bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterizing the role of pulmonary veins in pulmonary hypertension
Authors: Bazaz Abhishek , Chen Yen-Lin , Daneva Zdravka , Sonkusare Swapnil 
Published: May 2023

Pulmonary veins (PVs) transport oxygenated blood from lungs back to the heart. Small PVs can play a crucial role in the pathogenesis of pulmonary hypertension. Studies have also shown PV remodeling in pulmonary hypertension and heart failure. However, unlike pulmonary arteries (PAs), which have been a major focus of pulmonary vascular studies, the signaling mechanisms in PVs have not been investigated under normal conditions and in pulmonary hypertension. We hypothesized that the vascular wall composition and cellular signaling mechanisms in PVs are distinct from PAs. We imaged 4th order PVs (~ 50 mm) from C57BL6 mice using spinning disk confocal imaging along the z-axis. In direct contrast to PAs, where a single endothelial cell (EC) layer is surrounded by alpha actin-positive smooth muscle cells (SMCs), PV walls did not show SMCs. Cardiac troponin C staining of PVs identified cardiac myocyte-like (CML) cells with striations surrounding the EC layer. The CML layer was not observed in small PAs, vena cava, and mesenteric veins. Confocal calcium imaging showed spontaneous calcium signals in CML cells from PVs that were inhibited by ryanodine (1 mM), a ryanodine receptor inhibitor. Cannulated PVs in pressure myography experiments showed spontaneous pulsatile constrictions, which were also inhibited by ryanodine. Collectively, our results suggest that ryanodine receptor calcium signals in CML cells underlie spontaneous contractions in small PVs. Our findings also indicate that signaling mechanisms in CML cells could be potential targets for therapy in pulmonary hypertension. 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.
Neonatal Alveolar Type 1 Cells Produce a Pro-inflammatory Response to LPS and TNF-alpha
Authors: Mohammadi Atefeh , Higazy Randa , Ivanovska Julijana , Tran Harvard , Ivanovski Nikola , Gauda Estelle 
Published: May 2023

Introduction: Bronchopulmonary dysplasia (BPD) is the most common lung disease in premature infants. Inflammation and oxidative stress during the early stages of lung development damage alveolar Type 1 (AT1) and Type 2 (AT2) epithelial cells that line the alveoli, leading to decreased alveolarization and surfactant production. Unlike AT2 cells, the role of AT1 cells in inflammation is not understood. Since inflammation initiates BPD pathogenesis, we sought to characterize the profile of inflammatory markers produced by neonatal AT1 cells in response to lipopolysaccharide (LPS) and tumour necrosis factor α (TNF-α). Methods: AT1 cells were isolated from neonatal rats on postnatal day 4 using fluorescence activated cell sorting. Cells were serum starved for 24hrs and then exposed to LPS (5, 10, 25μg/mL), TNF-α (5, 10, 25ng/mL), or a combination of LPS and TNF-α (10μg/mL and 5ng/mL) for 18h in vitro. Conditioned media was collected for cytokine and chemokine analysis by multiplex ELISA. Results: AT1 cells exposed to both LPS and TNF-α produced a larger inflammatory response than those exposed to LPS or TNF-α alone. After 18h, AT1 cells from the combined LPS and TNF-α group increased the production of IL-6 by 243-fold, CCL2 by 34-fold, and CCL3 by 9-fold in comparison to the control (all p<0.05, n=4). IL-1β and IFN-γ, and the anti-inflammatory cytokines, IL-4 and IL-10, were not detected in any experimental groups at this time point. Conclusion: This is the first study that characterizes the response of neonatal AT1 cells to inflammatory stimuli. Our preliminary findings show that LPS and TNF-α stimulate the production of the pro-inflammatory cytokines and chemokines IL-6, CCL2, and CCL3 in primary AT1 cells. These inflammatory markers are strongly associated with the development of BPD and are predictors of adverse pulmonary outcomes in neonates. Developing therapies that regulate the inflammatory response produced by AT1 cells may be beneficial in mitigating BPD pathogenesis. This work was funded by the Women's Auxiliary of the Hospital for Sick Children. 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.
Role of Piezo2 in mechanosensation by vagal esophageal afferent fibers
Authors: Nair Sanjay , Hadley Stephen , Patil Mayur , Taylor-Clark Thomas 
Published: May 2023

The esophagus is densely innervated by extrinsic sensory afferents projected from the dorsal root and vagal ganglia capable of sensing mechanical and chemical stimuli. In particular a major subset of vagal afferents innervating the esophagus are low-threshold mechanoreceptors whose activation by esophageal stretch regulates homeostatic processes like peristalsis and upper and lower sphincter muscle movements in addition to swallowing and vomiting reflexes. Importantly, the identity of specific proteins that mediate mechanotransduction within the esophageal afferents is not known. Previous studies have identified Piezo2 as a mechanosensitive ion channel expressed in various sensory afferent subsets that is required for sensing lung and bladder inflation. Hence, we hypothesize that esophageal afferent fibers from the vagal ganglia sense mechanical distention through mechanically-gated Piezo2. Here, we used two-photon imaging of neuronal GCaMP6s fluorescence in an ex vivo vagal-esophageal preparation to measure the activation of esophageal afferents in response to pressure-evoked distension of the esophagus. For control studies, GCaMP6s was expressed from the knockin ROSA26 gene under the control of cre recombinase (B6.129S6-Gt(ROSA)26Sor-tm96(CAG-CGaMP6s)Hze), following cross with the Pirt-cre (which expresses Cre in all sensory neurons). To assess the role of Piezo2, we injected retrograde AAV (rgAAV2) vector encoding Cre recombinase with a tdTomato reporter into the esophagus of Piezo2fl/fl mice, combined with an intranodose injection of an AAV9 vector encoding GCaMP6s Ca2+-indicator. Only tdTomato-expressing neurons (i.e. cre expressing) were included in the GCaMP6s analysis of the Piezo2fl/fl mice. Our preliminary data from PIRT-GCaMP6s mice studies show that distention of the esophagus with 5, 10 and 30 mmHg caused profound Ca2+ influx in a select population of neurons in the vagal (nodose) ganglia (118 neurons analyzed), consistent with our previous electrophysiological studies of tension mechanoreceptors. However, we saw a reduction of >85% in the Ca2+ influx in response to esophageal distention (5, 10 and 30 mmHg) in the tdTomato+ esophageal afferent population following cre-mediated knockout of the Piezo2 channel (99 neurons analyzed). Our findings support our hypothesis that Piezo2 is required for sensing mechanical distention by esophageal afferents arising from the nodose ganglia. 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.
Nlrp3 inflammasome in the heart of hypothyroid mice
Authors: Parletta Aline , Vieira Junior Denival , Senger Nathalia , Barreto-Chaves Maria Luiza 
Published: May 2023

Cardiovascular diseases are the most common cause of death worldwide and thyroid diseases are frequently associated with cardiac function impairment. Hypothyroidism is related to dilation of the ventricles, fibrosis and consequent reduction in cardiac contractility, as well as an increased risk of heart failure. Recent studies have demonstrated the participation of the NLRP3 inflammasome, an important mechanism of the innate immune response, in cardiovascular diseases, such as myocardial infarction and atherosclerosis. There is evidence in the literature that hypothyroidism is accompanied by increased levels of cytokines and oxidative stress, processes that can activate the inflammasome. The aim of the present study is to evaluate the role of the NLRP3 inflammasome in the heart of hypothyroid mice. For this, Wild Type (WT) mice treated with methimazole (0.05% added to drinking water for 12 weeks) were used (N=4-6). All protocols used in this study were approved by the Animal Ethics Committee of the Institute of Biomedical Sciences (9768300119). Thyroid hormones were quantified by bead-based immunoassay Luminex to confirm the efficacy of experimental model. Fibrosis was analyzed by histology, using picrosirius red staining. Cardiac function was evaluated in mice by plethysmography and in isolated hearts after ischemia/reperfusion by the Langendorff method. Protein expression of NLRP3 inflammasome components was evaluated by Western Blotting. Data were analyzed by one-way ANOVA or Student's t test. Results are presented as mean ± standard error of the mean, and p<0.05 was considered statistically significant. Increased TSH levels (control=92±33, hypo=369±62 (pg/ml)) and reduced T4 (control=1.16±0.38, hypo=0.03±0.01 (ng/ml)) confirmed the hypothyroid status of mice. The heart weight/tibial length ratio and fibrosis were not altered by hypothyroidism. Heart rate was reduced in hypothyroid mice (control=663±27, hypo=541±28 (bpm)). No differences were detected in the cardiac function parameters after Ischemia-Reperfusion injury: left ventricular developed pressure (LVDP), maximum (dP/dtmax) or minimum first derivative (dP/dtmin). Concerning to inflammasome, NLRP3 expression was reduced (control=100±16, hypo=29±14 (%)) and pro-caspase 1 increased (control=100±17, hypo=259±43 (%)) in hypothyroid hearts. These preliminary results showed characterization data for experimental hypothyroidism and that this condition can modulate inflammasome expression. Additional experiments are underway to confirm the role of the NLRP3 inflammasome on cardiac function in hypothyroid mice. FAPESP (grants nº 2021/06151-7 and 2019/17031-2) 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.
Development of an inquiry-based physiology lab activity analyzing salivary cortisol
Authors: Walton Kristen 
Published: May 2023

Many of the classic lab activities in undergraduate animal or human physiology courses use specialized physiology recording equipment and software, and provide valuable illustrations of complex physiological processes in nerves, muscles, and the heart. However, some of the basic skills and equipment typical of many bench research labs are not as frequently represented. With a goal of increasing the diversity of common laboratory skills gained by students in our upper-division animal physiology course, as well as expanding lab activity options in endocrine physiology, a lab activity centered on measuring salivary cortisol was designed, using a commercially available, 96-well plate-based, relatively inexpensive enzyme immunoassay (EIA) kit. This activity was designed to give students the opportunity to learn the principles of EIA, which is commonly used for measuring hormones or other soluble molecules, as well as gain experience in pipetting, using a plate reader, and graphing data. This project was approved by the Missouri Western State University IRB. Students who volunteered to provide saliva samples were given saliva collection vials and instructions on sample collection. Samples were stored and processed according to the manufacturer’s instructions. The next week, student groups performed the cortisol immunoassay according to the kit instructions and calculated cortisol concentrations in the saliva samples based on the standard curve. In one semester, students collected saliva samples in the morning and evening, and determined whether their measured cortisol levels aligned with the expected diurnal variation in cortisol levels. In the next two course offerings, in a more inquiry-based design, students were given unlabeled samples and were asked to predict, based on the measured cortisol concentration, whether the samples may have been collected in the morning or evening. Other possible directions for a more inquiry-based lab activity could include testing samples collected before and after an intervention such as heavy exercise, studying for an exam, or relaxation or meditation techniques. When surveyed about their opinions on this lab activity, 63% of students agreed or strongly agreed that they liked the activity, and 69% agreed or strongly agreed that they learned new skills and/or understood concepts better after this lab activity. Students who disliked the activity mainly commented about the long wait time (a 45 minute incubation). In summary, this salivary cortisol enzyme immunoassay is a relatively inexpensive lab activity that is relatively well-received by students, and is feasible in the context of an undergraduate physiology lab. This activity adds to the body of options for lab activities in endocrine physiology. 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 effect of low-density lipoprotein cholesterol on T-cell mitochondrial respiration
Authors: DeConne Theodore , Ward Houston , Edwards David , Fancher Ibra , Trott Daniel , Martens Christopher 
Published: May 2023

Aging is associated with an increase in chronic, sterile, low-grade inflammation, known as “inflammaging” that is implicated in the development of multiple diseases, including cardiovascular disease. Immune cells are the primary source of inflammaging, of which T-cells play a major contributing role. Mitochondria are essential for maintaining proper T-cell function and reduced mitochondrial respiration (MitoRESP) induces T-cell dysfunction and shifts T-cells towards a pro-inflammatory phenotype. Elevated low-density lipoprotein cholesterol (LDL-C) is cross-sectionally associated with lower MitoRESP in circulating immune cells and may contribute to the inflammaging phenotype, but whether LDL-C is causally related to impaired MitoRESP in T-cells is not known. We hypothesized that treating T-cells in vitro with a high concentration of exogenous LDL-C would mimic accelerated aging by impairing T-cell MitoRESP from young adults. Seven young adults were recruited for this study (6 female / 1 male, age: 23 ± 2 years, BMI: 23.29 ± 6.4 kg/m2, total cholesterol: 154 ± 16 mg/dl, high-density lipoprotein cholesterol: 59 ± 17 mg/dL, & LDL-C: 78 ± 14 mg/dL). CD4+ and CD8+ T-cells were separated from peripheral blood mononuclear cells isolated using magnetic bead separation (Miltenyi). CD4+ and CD8+ T-cells were treated exogenously with a physiologically normal (1.8 mMol/L) and high (4.9 mMol/L) concentration of LDL-C for 24 hours. MitoRESP was assessed using extracellular flux analysis (Agilent). Compared with the low LDL condition, the high LDL-C condition lowered basal (0.47 ± 0.06 vs. 0.35 ± 0.10 pMol/min/105 cells, p=0.031) and ATP-linked oxygen consumption rate (OCR) (0.51 ± 0.13 vs. 0.35 ± 0.12 pMol/min/105 cells, p=0.016) in CD8+ T-cells. High LDL-C also lowered non-mitochondrial OCR (0.71 ± 0.22 vs. 0.57 ± 0.20 pMol/min/105 cells, p=0.016) and augmented basal glycolysis (0.097 ± 0.049 vs. 0.14 ± 0.036 pMol/min/105 cells, p=0.031) in CD8+ T-cells. High LDL-C lowered ATP-linked OCR (0.69 ± 0.23 vs. 0.54 ± 0.22 pMol/min/105 cells, p=0.031) and non-mitochondrial OCR (0.80 ± 0.17 vs. 0.68 ± 0.21 pMol/min/105 cells, p=0.016), but did not statistically alter basal OCR (0.47 ± 0.056 vs. 0.35 ± 0.10 pMol/min/105 cells, p=0.063) or basal glycolysis (0.14 ± 0.031 vs. 0.18 ± 0.028 pMol/min/105 cells, p=0.063) in CD4+ T-cells. Treatment with a high LDL-C accelerated aging in T-cells from young adults by impairing MitoRESP and shifting T-cells towards glycolytic metabolism. Future studies should explore the relation between age-related impairments in T-cell MitoRESP and cardiovascular function in humans. Funding Sources: P20GM113125 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.
LncRNA H19 Regulates Intestinal Serotonin Transporter (SERT) Expression
Authors: Natarajan Anbazhagan Arivarasu , Frank Griggs Theodor , Sharma Dhara , Kaur Prabhdeep , Priyamavada Shubha , Jayawardena Dulari , Kumar Anoop , Saksena Seema , Alrefai Waddah , Tan Xiao-Di , Dudeja Pradeep , Gill Ravinder 
Published: May 2023

Background: Serotonin transporter (SLC6A4; SERT) plays a key role in regulating the availability of 5-HT (5-hydroxytryptamine, a neurotransmitter and hormone) in the brain and the gut mucosa. A decrease in intestinal SERT expression, associated with increased availability of 5-HT, is implicated in the pathogenesis of infectious and inflammatory disorders of the gut. Therefore, it is critical to understand the regulation of SERT, as a novel target for the treatment of gastrointestinal disorders. In this regard, long noncoding RNAs (LncRNAs, small transcripts >200 nucleotides) are known to modulate gene expression via chromatin remodeling, transcriptional and posttranscriptional mechanisms. Notably, elevated levels of LncRNA H19 are observed in IBD patients and mouse models of inflammation and are known to promote mucosal regeneration and wound healing and restore the intestinal homeostasis. Whether LncRNA H19 regulates SERT expression remains unknown and was the focus of the current study. Methods: Caco-2 cells were transiently transfected with either H19 mammalian expression vector or H19 siRNA using Lipofectamine 2000. Protein and mRNA expression was measured by immunoblotting and real-time PCR, respectively. Age-matched H19 lncRNA- deficient mice and wild-type (WT) littermates were used to determine the role of genetic deletion of H19 on SERT expression in ileum. Results: H19 overexpression in Caco-2 cells increased SERT mRNA levels (~13-fold; p<0.05) at 48h post-transfection compared to an empty vector. Consistent with the mRNA levels, H19 also increased SERT protein expression (~2-fold, p<0.05). Furthermore, siRNA-mediated knockdown of H19 in Caco-2 cells resulted in a significant decrease in SERT mRNA levels (~80%, p<0.05). Parallel to the in vitro results, H19 deficient mice also showed a significant decrease in SERT mRNA expression (~69 %, p<0.05) in the ileum compared to the WT mice. Interestingly, in comparison to WT, the expression of other key transporters involved in intestinal NaCl absorption (SLC9A3, SLC26A3, and SLC26A6) remained unaltered in H19 deficient mice. Conclusion: These data demonstrate a novel role of LncRNA H19 in regulating the expression of SERT in the intestine under physiological conditions. We speculate that H19 mediated increase in SERT expression may provide valuable insights into the mechanisms restoring decreased SERT expression in inflammatory or infectious diseases of the gut. (Supported by VA/NIH). VA and NIH 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.
Investigating microvascular outcomes with ischemic pre-conditioning and passive stretch
Authors: Fenn Sarah , Walker Maxwell , Bekkedal Lukas , Bundy Rob , Bratsch Amanda , Caldwell Jacob 
Published: May 2023

INTRODUCTION: Passive stretching (PS) elicits hypoxia of the skeletal muscle that is similar to limb occlusion like that shown with ischemic pre-conditioning (IPC). However, the magnitude of responses between PS and IPC as they pertain to vascular outcomes are unknown. The purpose of this study is to investigate intermittent passive stretch to intermittent ischemic pre-conditioning on microvascular responsiveness. Given the increased metabolic activity during PS, we hypothesized that passive stretch will be a more effective method to improve microvascular function than IPC. METHODS: 5 preliminary college-aged subjects participated in this randomized, crossover, study that included 2 lab visits with a one-week washout period. Each visit started with a rest period where baseline blood pressure and heart rate were taken. A post occlusive reactive hyperemia (PORH) test was performed prior to and after each intervention. An intervention of PS or IPC consisting of 5-minutes “on” 5-minutes “off” four times through occurred after pre-testing. IPC consisted of bilateral cuff inflation on the upper thigh to 220mmHG to ensure full occlusion. PS consisted of splinting devices placed bilaterally on the subject’s feet where they were stretched to a degree of moderate discomfort. The PORH was repeated after each intervention. A 2-way repeated measures ANOVA was performed to compare group (PS vs. IPC) by time (pre vs. post). Statistical significance was set at p<0.05. RESULTS: Our preliminary data suggest a main effect of time for IPC (p=0.04) (pre: 0.071 ± 0.029 %/s-1), (post 0.095 ± 0.028 %/s-1) and posed a tendency (p=0.11) for PS (pre: 0.064 ± 0.040 %/s-1), (post: 0.080 ± 0.030 %/s-1) to increase microvascular responsiveness. In either group, slope 1; resting muscle metabolism was not significantly different (p>0.05). CONCLUSION: The current preliminary results suggest that PS, a foreseeable asset to macrovascular modulation, may also present itself as an impactful facilitator for microvascular responsiveness when compared to IPC. However, more data is needed to further solidify this relationship. This study was funded through supported start-up funds by the University of Wisconsin-La Crosse. 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.