bluuebunny/crossref_metadata_2025_split huggingface dataset:
Peripheral blood mononuclear cells isolated from e-cigarette users have a greater inflammatory cytokine response to LPS stimulation compared to controls
Authors: Wetzel Elizabeth , Cho Josalyn , Stanhewicz Anna 
Published: May 2024

Chronically elevated inflammation is a contributing factor in the development and progression of chronic disease, including cardiovascular disease. Biomarker studies suggest that chronic e-cigarette use is associated with elevated circulating inflammatory cytokines and overall vascular inflammation. However, few studies have examined measures of immune cell activity in e-cigarette users. We hypothesized that healthy young adults (18-24 years) who chronically (history of use ≥6 months) and exclusively use e-cigarettes (EC) would have higher plasma concentrations of the inflammatory cytokine TNFα compared to healthy controls (HC), and that peripheral blood mononuclear cells (PBMC) isolated from EC would release more TNFα when stimulated with lipopolysaccharide (LPS) compared to PBMC isolated from HC. 9 HC (20±2 years) and 10 EC (20±1 years; 4±2 years of e-cigarette use) participated in 1 study visit in which we collected 20mL of whole blood via venipuncture and isolated plasma and PBMC. PBMC were incubated in RPMI and 10% FBS with or without 1mg/mL LPS (37°C, 5% CO2). PBMC supernatants were collected at 4 and 24 hours and TNFα concentrations were quantified in plasma and supernatant samples via ELISA. EC had greater plasma TNFα concentrations compared to HC (HC: 1.7±1.5 vs. EC: 3.1±2.7 pg/mL; p=0.03). PBMC supernatants from EC had elevated TNFα following 4 (HC: 28.0±16.9 vs. EC: 52.1±46.5 pg/mL; p=0.04) and 24 (HC: 87.7±71.6 vs. EC: 178.9±121.0 pg/mL; p=0.04) hours of LPS stimulation compared to HC. There were no group of time differences in TNFα in supernatants from unstimulated PBMC (all p>0.05). These data agree with prior findings that chronic e-cigarette use is associated with elevated circulating inflammatory cytokines and suggest that mononuclear cells of e-cigarette users have a greater cytokine response to inflammatory stimuli. NIEHS/NIH P30 ES005605. This is the full abstract presented at the American Physiology Summit 2024 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.
SARS-CoV-2 Decreases Neuronal Activity in Brainstem Respiratory Centers in C57BI6/J Mice
Authors: Restivo Luke , Pasley India , Miller Ryan , Yakoub Abraam , Tseng Chien-Te K , Lazartigues Eric 
Published: May 2024

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), also called COVID-19, targets the respiratory system, leading to symptoms such as cough, fever, and diffculty breathing. As the mechanisms behind SARS-CoV-2 infections continues to be studied, understanding of how this virus targets specific tissues becomes more apparent. Angiotensin-converting enzyme-2 (ACE2), the target of SARS-CoV infections and a functional receptor for SARS-CoV-2 invasions, is highly expressed in many tissues throughout the body, including the lungs, kidneys, and brain. Notably, our group previously reported that neurons are the main cells within the brain expressing ACE2. Accordingly, we hypothesized that neuronal infection of brainstem respiratory centers by SARS-CoV-2 could contribute to respiratory symptoms associated with COVID-19, specifically respiratory failure. C57BI6/J mice were mock infected or received SARS-CoV-2 (7.5x103 or 1.5x104) intranasally in a BSL-3 facility (University of Texas in Galveston) and were euthanized by CO2 hypoxia after 5 days post infection. The heads were harvested and immersed in formalin for 3 days before being transferred to LSU Health-NO for processing. Brains were carefully dissected out and preserved in optimal cutting temperature (OCT) before sectioning on a cryostat. Sections (30 μm) containing the retrotrapezoid nucleus (RTN) were selected as its neurons are part of the pontomedullary regions that generate the respiratory rhythm and pattern. Immunohistochemistry for c-Fos, a marker of neuronal activity, was used to assess neuronal activity in the RTN. Sections were incubated overnight with a primary monoclonal antibody (rabbit anti c-Fos, 1:1000) followed with a secondary goat antirabbit fluorescent IgG (GFP, 1:200, 1h) antibody. Sections were then mounted to slides in the dark to preserve the fluorescence and observed under the microscope. Images of neurons present in the RTN were captured and neurons were then hand counted and averaged. Neuronal activity in the RTN was decreased with the dose of SARS-CoV-2 used to infect cells in the brain. The greater the dose of SARS-CoV-2, the lower the number of c-Fos-positive neurons was detected in the RTN. Mock brains had the greatest number of neurons and brains infected with 1.5x104 SARS-CoV-2 had the lowest number of neurons in the RTN. This was demonstrated by counting neurons at 3 different intervals and taking the average. We conclude that SARS-CoV-2 targets neurons in respiratory centers, possibly contributing to impaired respiratory function in infected patients. NIH/NHLBI HL163814. This is the full abstract presented at the American Physiology Summit 2024 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.
Resident macrophages in kidney medulla are critical in cleaning intratubular sedimentary particles
Authors: Shen Xiao (Gregory) , he jian , Shi Peng 
Published: May 2024

During the passage of the glomerulus filtrate through the renal tubular system, various microscopic sedimentary particles, including mineral crystals resulting from urine concentration, are generated. Dislodging these particles in the intratubular compartment is critical to ensure free flow of filtrate and the final formation of urine. However, it is generally assumed that particle removal is solely attributed to urine flush and whether there is other devoted mechanism is unknown. In this study, we uncovered that most macrophages in the kidney medulla of mice constitutively formed transepithelial protrusions and were “sampling” urine contents, as revealed by high-resolution confocal microscopy. This phenomenon was less pronounced in the cortex. The transepithelial protrusions of medulla macrophages were formed in a transcellular route instead of between epithelial cells, so the overall junctional architecture of tubular epithelium was intact. Juxtatubular macrophages were effcient in sequestering and phagocytosing intraluminal particles through their transepithelial protrusions, and would make transmigration to the tubule lumen to "escort" the excretion of sediment particles, as documented by live two-photon microscopy recording. In accordance, abundant particle-carrying macrophages could be detected in the urine. As such, specifically depleting renal macrophages precipitated kidney stone formation in a hyperoxaluria model. Moreover, naïve mice with underrepresentation of renal macrophages were prone to developing various intratubular sediments. RNA-seq analyses unveiled that medulla macrophages were enriched with genes associated with cell adhesion relative to cortex macrophages. Mechanistically, we found that integrin β1-mediated ligation to the tubular epithelium was crucial to the transepithelial behaviors of medulla macrophages, as evidenced by both pharmacological and genetic approaches. This study unveils a previously unappreciated role of renal medulla macrophages in keeping the tubular system unobstructed by removing intratubular particles. These findings may pave way for developing novel therapeutics for nephrolithiasis. National Natural Science Foundation of China (32170894, 31970898 and 82170441) and the Natural Science Foundation of Zhejiang Province (LZ22C080001). This is the full abstract presented at the American Physiology Summit 2024 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.
Streptococcus pneumoniae infection promotes the long-term development of an atherosclerotic phenotype in atheroprone ApoE-deficient mice
Authors: Peters Lisa , Simmons Szandor , Ginsbach Laura F. , Ramezani Rad Pegah , Brack Markus C. , Nageswaran Vanasa , Behrendt Ulrike 
Published: May 2024

Background: Epidemiological studies have identified pneumonia to be closely linked to an increased risk for cardiovascular events. Potential causality of this association, however, remains to be established, and underlying mechanisms are yet to be resolved. Here, we tested the hypothesis that prior pulmonary infection with Streptococcus pneumoniae accelerates the development of an atherosclerotic phenotype in mice. Such a phenotype would explain the increased cardiovascular risk in the epidemiological data. Methods: Atheroprone ApoE−/− mice were fed a high fat diet, and after 6 weeks nasally infected with either 2.5 x 107 S. pneumoniae or vehicle control. Antibiotic therapy was initiated 60h post infection (p.i.) by s.c. injections of ampicillin on 5 consecutive days followed by oral administration of amoxicillin for 10 days. At days 35 or 90 post-infection, aortas were harvested and assessed for vasoreactivity and arterial stiffness by wire myography. Morphological changes of the aortic vessel wall and eNOS expression levels were quantified by western blot and histological stainings. Results: Unexpectedly, 35 days p.i. aortas of infected mice presented with decreased aortic stiffness, increased endothelial-independent vasorelaxation and decreased wall thickness due to lower collagen-1 expression and reduced elastin fragmentation when compared to sham animals. After 90 days, however, these effects had reversed and animals with prior pneumonia showed increased aortic stiffness, attenuated endothelial dependent vasorelaxation that was associated with reduced eNOS protein expression and phosphorylation, and increased atherosclerotic plaque burden relative to vehicle control. Conclusion: Single episodes of pneumonia promote a delayed pro-atherogenic phenotype that manifests as endothelial dysfunction, aortic stiffening and enhanced plaque burden. Underlying mechanisms are currently under investigation to identify risk predictors for patient stratification and clinical targets for prevention of cardiovascular disease following pneumonia. Funding: German Ministry of Education and Research (BMBF) in the framework of SYMPATH (01ZX1906A). This is the full abstract presented at the American Physiology Summit 2024 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.
Elucidation of the Molecular Signal Linking Psychological Trauma to T-lymphocyte Inflammation
Authors: Natour Tamara , Lauten Tatlock H. , Reed Emily C. , Case Adam J. 
Published: May 2024

Post-traumatic stress disorder (PTSD) is a psychiatric disorder that not only exhibits significant behavioral pathology, but also increases the likelihood of comorbid inflammatory conditions such as autoimmune and cardiovascular diseases. While PTSD patients experience heightened systemic inflammation, the exact link between psychological trauma and immune dysregulation remains to be elucidated. Our group has recapitulated the psychological trauma-induced inflammatory phenotype in a pre-clinical murine model of PTSD known as repeated social defeat stress (RSDS). Importantly, a key site of this inflammation appears to originate from T-lymphocytes in the spleen, and targeted splenic nerve denervation was able to completely prevent splenic T-lymphocyte inflammation after RSDS (p<0.0001). This critical observation suggests the T-lymphocyte response to psychological trauma is neural derived as opposed to circulating, therefore, we began systematic investigation into possible neural-derived signals that may lead to enhanced T-lymphocyte inflammation. To investigate whether the signal involves the T-cell receptor (TCR), we utilized OT-I and OT-II mice that possess non-mouse antigen-restricted TCRs. RSDS induced T-lymphocyte inflammation in these mice similar to wild-type, therefore, suggesting the signal is not antigenic in nature (p>0.05). Next, we examined the role of norepinephrine and adrenergic signaling using both pharmacological blockade and genetic knockouts of both alpha and beta adrenergic receptors, but this too was insuffcient to reverse the RSDS-induced T-lymphocyte inflammation (p>0.05). Following this, we examined the role of damage associated molecular patterns (DAMPs) by pharmacological blockade of the toll-like receptor 4 (TLR4), yet again, this intervention did not attenuate T-lymphocyte inflammation after RSDS (p>0.05). Last, our data suggests interleukin 6 (IL-6) is upregulated early after psychological trauma; therefore, we examined the role for cytokine-induced T-lymphocyte inflammation. Using anti-IL-6 antibodies during RSDS, T-lymphocyte inflammation appeared blunted compared to wild-type animals (p<0.05). Moreover, T-lymphocytes treated with only IL-6 expressed similar inflammation gene profiles as those from RSDS animals (p<0.05). Taken together, our data suggest IL-6 may be the T-lymphocyte inflammation-inducing signal, but additional studies are warranted to understand the exact source of IL-6 and mechanisms underlying IL-6’s ability to drive T-lymphocyte inflammation. R01HL158521. This is the full abstract presented at the American Physiology Summit 2024 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.
Machine learning techniques for predicting microvascular network hemodynamics
Authors: Ebrahimi Saman , Bagchi Prosenjit 
Published: May 2024

Existing techniques to image microvascular networks in vivo do not allow a direct and accurate measurement of several hemodynamic variables such as the wall shear stress (WSS). They cannot also provide a full 3D characterization of blood velocity and red blood cell (RBC) concentration profiles in every vessel in a microvascular network. Such physiological parameters however play critical roles in blood flow regulation, disease progression, angiogenesis, and hemostasis. Theoretical models of network blood flow, often used for hemodynamic predictions in experimentally acquired images of the microvascular network, cannot provide the full 3D blood velocity, RBC concentration and WSS profiles as these models assume one-dimensional flow governed by Poiseuille’s law. In contrast, high-fidelity computational models that simulate flow of blood as a suspension of deformable RBCs and model the 3D vessel geometry can readily predict such physiological variables with high accuracy. Such high-fidelity computational models have recently been applied to predict hemodynamic variables in microvascular networks in silico composed of many vessels and vascular junctions. Such models, however, tend to become computationally expensive with increasing size of the network; therefore, they are not feasible for use in large networks at organ scale. To overcome this limitation, we developed a machine learning (ML) approach that can predict hemodynamic variables in 3D and with high accuracy. The ML models are based on artificial neural network and convolution-based U-net models. Using experimentally acquired images of the microvascular networks, inputs at a few inlets, and a “bank” of database that we have developed, these ML models can predict flow and RBC distribution in all vessels in the network, 3D blood velocity and RBC concentration profiles over the cross-section of every vessel, 3D WSS profiles, and time-dependent variations in blood flow in any vessel. The prediction from the ML models compare very well against the true data. Also, the prediction time using ML is significantly less than that of the high-fidelity models. The current ML models, which to our knowledge are the first of their kind, are highly promising for image-based predictions of sub-cellular resolved capillary hemodynamics in organ-scale networks. This study paves the way for AI to make hemodynamic predictions in organ-scale capillary vessel networks while retaining the sub-cellular scale details and overcoming the limitations of the in vivo imaging techniques, with potential applications in hematological and microvascular disorders, angiogenesis, and vascular-mediated drug delivery. Funded by NIH (R01-EY033003) and NSF (CBET 2302212). This is the full abstract presented at the American Physiology Summit 2024 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.
Role of ERK and NF-KB pathway in neurally mediated enhanced expression and traffcking of SGLT2 in congestive heart failure
Authors: Patel Tapan , Zheng Hong , Patel Kaushik 
Published: May 2024

Congestive heart failure (CHF) is characterized by the activation of neurohumoral systems concomitant with avid fluid retention. Recently we showed enhanced expression of sodium-glucose cotransporter 2 (SGLT2) in rats with CHF. However, the exact molecular mechanism linking enhanced sympathetic tone and enhanced expression and translocation of SGLT2 in CHF is not clear. The objective of this study was to investigate the role of enhanced sympathetic tone on the expression and traffcking of SGLT2 via activation of protein kinase A (PKA), extracellular signal-regulated kinases (ERK), and nuclear factor kappa B (NF-KB) in the renal cortex of CHF rats. Male Sprague Dawley rats were subjected to either the left coronary artery ligation for the CHF group or Sham surgery. Four weeks after surgery, expression of protein levels (PKA, ERK and NF-KB) were assessed by Western blotting, whereas the location of SGLT2 expression was determined by immunohistological and immunofluorescent staining in the cortical region of kidneys from Sham and CHF rats. Effect of exogenous norepinephrine (NE) (10μM for 24hrs) on expression and traffcking of SGLT2, phosphorylation of ERK and NF-KB in HK2 cells were examined in an in vitro model. Expression of SGLT2 was significantly enhanced in the renal cortex of rats with CHF versus Sham (0.83±0.06 vs. 0.58±0.02). Also, the translocation of SGLT2 was significantly enhanced towards the membrane in CHF rats (0.92±0.11 vs. 0.33±0.07). Phosphorylation of PKA (0.05±0.01 vs. 0.01±0.01), ERK (0.32±0.02 vs. 0.23±0.02) and NF-KB (0.71±0.14 vs. 0.08±0.06) were significantly enhanced in CHF compared to Sham. NE treatment significantly increased expression of SGLT2 (0.26±0.03 vs. 0.15±0.02), traffcking of SGLT2 (0.45 ± 0.09 vs. 0.15 ± 0.03) towards membrane, phosphorylation of ERK (0.38±0.05 vs. 0.14±0.02) and NF-KB (0.61±0.08 vs. 0.17±0.07) in HK2 cells. Thus, NE treatment enhanced the phosphorylation of ERK, NF-kB as well as traffcking of SGLT2. Immunohistological and immunofluorescent staining demonstrated increased expression of SGLT2 in the kidneys of rats with CHF. Similar results were observed in immunofluorescent staining of human kidney cells treated with NE. In conclusion, these findings indicate that NE activates ERK and NF-KB pathways which leads to enhanced traffcking and overexpression of SGLT2 in CHF. These results provide a molecular link between enhanced sympathetic tone, ERK and NF-KB pathway and the traffcking of SGLT2 to the luminal membrane of renal proximal tubular cells and consequent increase in sodium retention in rats with CHF. This study was funded by NIH R01-DK-129311. This is the full abstract presented at the American Physiology Summit 2024 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 role of PPP1R3G in promoting necroptosis in ischemia reperfusion induced acute kidney injury
Authors: Tran Minh , Parris Colby , Wang Lei 
Published: May 2024

Recent discoveries have revealed necroptosis as a major contributor to the pathogenesis of acute kidney injury (AKI). Protein phosphatase 1 regulatory subunit 3G (PPP1R3G) has been linked to the essentiality of RIPK1-dependent apoptosis and type I necroptosis. Nonetheless, the involvement of PPP1R3G in the regulation of necroptosis during ischemia reperfusion-induced acute kidney injury (IR-AKI) has yet to be elucidated. Here, we investigated the role of PPP1R3G in the regulation of necroptosis in IR using an in vitro cellular I/R model and in vivo IRI-AKI mouse model. Primary proximal tubular cells (PTCs) from C57BL/6 and Ppp1r3g−/− mice were cultured and cell I/R was induced through hypoxia/reoxygenation. Cell viability and necroptosis were analyzed using CellTiter-Glo assay and Annexin V-Cy3/ SYTOX green staining, respectively. The expression levels of necroptosis, oxidative stress, and inflammation factors were determined by real-time PCR, western blotting, immunofluorescence staining, and ELISA. In the in vivo IRI-AKI model, bilateral renal pedicles clamping was conducted in both C57BL/6 and Ppp1r3g−/− mice. The kidney injury and function were evaluated by plasma creatine, BUN, and KIM-1 levels and GFR values, respectively. Kidney morphological evidence of injury was assessed by PAS staining and cell death by immunofluorescent staining. We found that knockout of PPP1R3G in the primary tubular cells significantly preserved cell viability and attenuated tubular cell death. This protective effect was associated with the reduced expression and phosphorylation of necroptosis factors (RIP1, RIP3, and MLKL), and inflammatory factors (IL-6, IL-10 and TNF-α) in I/R injury cells. Deletion of PPP1R3G attenuated the I/R induced kidney injury indicated by 54% decrease in the plasma creatine (2.28±0.12mg/dL vs. 1.09±0.07mg/dL, p<0.0001, n=7) and 45% higher GFR values than WT mice at day 3 after reperfusion. Histology showed less diffuse renal tubular necrosis and casts comprising necrotic cells and debris in Ppp1r3g−/− mice, as well as 60% less cell death compared to WT mice. Moreover, the application of chemical compounds to prevent inhibitory phosphorylation of RIPK1 significantly reinstated cell death in Ppp1r3g−/− cells. In conclusion, our findings demonstrate, for the first time, that Ppp1r3g-mediated necroptosis significantly promotes IRI-AKI. Therefore, targeting Ppp1r3g to reduce necroptosis in the kidney holds promising potential for significant clinical benefits. National Institutes of Health Department of Molecular Pharmacology and Physiology, University of South Florida College of Medicine, Tampa, FL. This is the full abstract presented at the American Physiology Summit 2024 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.