bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigating the contribution of cytokinesis to population-based measurements of epithelial Leak Pathway permeability
Authors: Monaco Ashley , Amsler Kurt 
Published: May 2023

The mechanism mediating the paracellular movement of macromolecules across epithelial cell layers, the Leak Pathway, remains poorly understood. Two recent studies have demonstrated that epithelial cell cytokinesis allows the transient paracellular passage of macromolecules (Stephenson et al. 2019. Dev Cell 48:445-459, Richter et al. 2022. Ann NY Acad Sci 1516:151- 161). It is unclear, however, if this cytokinesis-mediated transepithelial passage of macromolecules can contribute significantly to the Leak Pathway permeability measured in a post-confluent epithelial cell population. The renal epithelial cell line, Madin Darby Canine Kidney (MDCK II), develops tight junctions and forms a typical paracellular permeability barrier upon reaching a confluent density. MDCK II cells have been reported to maintain a basal rate of cell proliferation, even in post-confluent cell populations. To investigate the role of cytokinesis in contributing to population-based measurements of Leak Pathway permeability, we examined the effect of arresting and releasing cytokinesis in post-confluent populations of MDCK II cells on Leak Pathway permeability. We confirmed that post-confluent populations of MDCK II cells exhibit a low level of cell proliferative activity. Leak Pathway permeability was determined by measuring the flux of 20 kDa fluorescein-dextran across post-confluent populations of MDCK II cells grown on permeable membrane filters. Inhibiting cytokinesis of MDCK II cells by overnight treatment with RO-3306, a CDK-1 inhibitor, decreased modestly the paracellular flux of 20 kDa fluorescein-dextran compared to untreated cell populations. Washing out RO-3306 1 hour prior to the flux assay produced an increase in paracellular flux of 20 kDa fluorescein-dextran to a level higher than that observed in untreated cell populations. Our results support the working hypothesis that cytokinesis can contribute to Leak Pathway permeability measured in epithelial cell populations. They suggest that more proliferative epithelial cell populations will exhibit higher rates of Leak Pathway permeability compared to epithelial cell populations with very low levels of proliferative activity. The significant Leak Pathway permeability measured in MDCK II cell populations maintained in the presence of RO-3306 suggests that cytokinesis is not the sole mechanism mediating Leak Pathway permeability across epithelial cell populations. 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.
TUDCA treatment restores anticontractile function of perivascular adipose tissue (PVAT) in post-weaning protein-restricted mice
Authors: Davel Ana , Freitas Israelle , Victorio Jamaira , Carneiro Everardo 
Published: May 2023

Healthy perivascular adipose tissue (PVAT) has anticontractile, anti-inflammatory and antioxidant actions that can be disrupted by cardiometabolic risk factors. In the present study we hypothesized that protein restriction in the early phases of development could result in PVAT dysfunction and tauroursodeoxycholic acid (TUDCA) could be beneficial by inhibiting endoplasmic reticulum stress (ERS). To test this hypothesis, post-weaning male and female mice fed a normoprotein (NP, 14% protein) or a low protein (LP, 6% protein, isocaloric) diet for 15 weeks. In the last 2 weeks, some NP and LP animals received TUDCA (300 mg/kg/day) or vehicle. At the end of treatment, thoracic aorta was isolated to assess vascular responses with or without adjacent PVAT, as well as PVAT gene expression and histology. As results, the presence of PVAT reduced the phenylephrine-induced contraction in aorta of female NP and LP and male NP but not in male LP, suggesting LP-induced PVAT dysfunction in males only. In males, aortic PVAT from LP group showed less lipid content and increased collagen deposition. Decreased expression of PRDM-16, PPAR-γ, PGC-1α and leptin was observed in PVAT of LP group. These functional and morphological PVAT alterations in males were reversed by TUDCA treatment. Because TUDCA inhibits ERS, next we evaluated gene expression of ERS markers. There was an increased expression of GRP78, ATF4/6, IRE1α, and CHOP in PVAT from LP group, which was normalized by TUDCA. Also, TUDCA treatment normalized the reduced PVAT expression of the TUDCA receptor FXR in LP group. In conclusion, our data suggest that post-weaning protein-restriction impairs PVAT function and structure in males. These changes were associated with decreased expression of adipogenesis and adipocyte differentiation factors, and increased ERS markers. TUDCA reversed protein-restriction-induced PVAT abnormalities. Therefore, TUDCA emerges as a potential therapy for vascular complications associated with early undernutrition. The authors have nothing to disclose. 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.
Primary Isolated Mouse Aortic Smooth Muscle Cells Phenotypic Characterization and Mitochondrial Respiration
Authors: Sakamuri Anil , Kamau Anne , Ogola Benard 
Published: May 2023

Sexual dimorphism is demonstrated in cardiovascular disease (CVD). Vascular dysfunction is a critical player in CVD involving mitochondrial respiration in aortic smooth muscle cells. In this study, we characterized contractile and synthetic gene expression, and mitochondrial respiration by sex in aortic smooth muscle cells (ASMC). We hypothesize that female than male ASMC have increased contractile genes and better mitochondrial energetics. Adult male and female C57BL6J mice were euthanized, and thoracic aorta excised. Aortic tissue sections were subject to enzymatic digestion and cultured for subsequent experiments. The 2-delta delta CT method using beta actin as housekeeping gene was used for analysis. For mitochondrial respiration, confluent (70%) cells were trypsinized, enumerated, and seeded in Seahorse mini-culture plates (20,000 cells/well). After overnight incubation mitochondrial stress test was performed to measure basal respiration, maximal respiration, spare capacity, ATP production, proton leak, and non-mitochondrial respiration. All mitochondrial respiratory parameters were expressed as oxygen consumption rate normalized with protein levels (OCR, picomoles/L of O2 per microgram protein, n=8-10 wells/group). Unpaired t-test was used for statistical analysis and P<0.05 was considered significant. To characterize the sex of isolated cells (n=6-8/group), we used sex specific primers that showed significantly higher Sry (P<0.001) and Xist (P<0.001) gene expression of male and female ASMC, respectively. Next, we assessed contractile and synthetic genes including myocardin, alpha actin, and myosin heavy chain 11 that were higher in female than male ASMC (P<0.05). However, myosin heavy chain 10 was higher (P=0.002) in male than female cells. The basal respiration and ATP production were significantly high in female ASMC by 79% and 77%, respectively, when compared with male ASMC (2.48 ± 0.13 vs. 1.38 ± 0.15, P= 0.0001; 2.11 ± 0.11 vs. 1.19 ± 0.11, P= 0.0001). Female cells indicated increased spare respiratory capacity compared to male ASMC (1.67 ± 0.31 vs. 1.1 ± 0.23, p= 0.01). The maximal respiration and proton leak were significantly higher in female than male cells by 69% and 109% (4.21 ± 0.33 vs. 2.49 ± 0.31, P= 0.001: 0.42 ± 0.02 vs. 0.2 ± 0.04, P= 0.001). Female and male cells did not show any significant difference in non-mitochondrial respiration. Based on these results, female than male ASMC exhibit increased contractile gene expression and better mitochondrial energetics at basal and stressed conditions. The sex-specific differences in mitochondrial function may attribute to sex bias in CVD. R00HL155841 and R25HL105400 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.
High-resolution temporal transcriptomic profiling of the distal convoluted tubule identifies an early adaptive response to furosemide
Authors: Jung Hyun Jun , Tahaei Ebrahim , Welling Paul 
Published: May 2023

The distal convoluted tubule (DCT) undergoes hypertrophy and hyperplasia to increase salt absorption in response to physiologic and pathological stresses, and has been implicated in the development of loop-diuretic resistance. However, the molecular mechanisms underlying DCT remodeling are unknown. We investigated progressive changes in the transcriptome of the early DCT (DCT1) in a time series (12, 24, 48, and 96 hours) after the administration of furosemide to identify initiating gene regulatory pathways. For high-resolution coverage, RNAseq was performed on isolated DCT1 segments, identified using a DCT1-specific Cre-driven fluorescent protein, tdTomato. An average of 17 million sequences were read per sample, providing genome-wide coverage of the DCT transcriptome (15499 genes). Sequence reads aligned on the mouse transcripts were quantified using Salmon, and differential gene expression analysis was performed using edgeR. All samples were enriched with known DCT-specific genes and lacked other nephron segment specific markers, indicating uniform purification of DCT tubules. Pathway and pattern clustering analysis of the time-resolved DCT transcriptome profiles revealed the early-induced genes were highly enriched in gene sets associated with cell cycle progression and cell proliferation. Meta-analysis of transcription factor binding enrichment at promoters of the early-induced genes revealed enrichment of genomic binding sites of Hypoxia-inducible factor 1 (HIF-1) signaling components (HIF1A, STAT3, RELA) across the early-induced gene promoters. Immunoblot analysis in kidney cortical tissues confirmed rapid activation of the HIF-1 signaling components following furosemide treatment. In summary, a core transcriptional regulatory axis in the DCT is activated rapidly after loop-diuretic treatment to drive a program of cell proliferation in the DCT. The results identify HIF1 signaling as a proximal pathway in the initiation of proliferative DCT remodeling. NIDDK, LeDucq Foundation 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.
Sex-specific impact of angiotensin II on arterial pressure and LV mass during angiotensin converting enzyme inhibition in spontaneously hypertensive rats
Authors: Floyd Dana , Garvin Alexandra , Hale Taben 
Published: May 2023

Sex differences in arterial pressure responses to angiotensin II (AngII) have been noted, particularly in normotensive animals. In addition, sex-specific changes in renin angiotensin system (RAS) components have been implicated in differential regulation of arterial pressure between males and females. The present study evaluated the sex-specific responses to AngII infusion, angiotensin converting enzyme inhibitor (ACEi) treatment, and AngII infusion during ACEi treatment on mean arterial pressure (MAP) and left ventricular hypertrophy (LVH) in spontaneously hypertensive rats (SHR). Young adult male and female SHR were treated with the ACEi, enalapril (30mg/kg per day, p.o.) alone or in combination with AngII at a low (200 ng/kg per min) or high (400 ng/kg per min) dose for two weeks. MAP was measured by radiotelemetry and data presented as percent change from pre-treatment baseline. At time of sacrifice, left ventricles were excised and weighed and normalized to body weight. ACEi induced equivalent percent reductions in MAP between male (-21 ± 1.2%) and female (-23 ± 1.9%) SHR. AngII (high) infusion significantly increased MAP, with a tendency toward a greater effect in male compared to female SHR (male: 29 ± 4.6% vs. female: 17 ± 3.6%, p=0.09). During ACEi, low dose Ang II did not significantly impact the antihypertensive effect of ACEi in males or females. However, administration of the high dose of AngII during ACEi resulted in a marked sex difference whereby the male SHR exhibited an increase in arterial pressure (ACEi: -21.22% ± 1.21, ACEi+AngII high: +39.49% ± 1.39, p<0.05), while in females AngII had no impact on the depressor response to ACEi alone (ACEi: -22.59% ± 1.89, ACEi+AngII high: -18.14% ± 0.88, p>0.05). Evaluation of left ventricular hypertrophy (LVH) revealed a similar sex difference. The low dose of AngII prevented the reversal of LVH induced by ACEi in male (Con: 2.54 ± 0.09, ACEi: 1.99 ± 0.04*, ACEi+AngII: 2.34 ± 0.13†, *p<0.05 vs. Con, †p<0.05 vs. ACEi), but not female rats (Con: 2.95 ± 0.02, ACEi: 2.43 ± 0.04*, ACEi+AngII: 2.46 ± 0.09*, *p<0.05 vs. Con). In summary, ACEi produces equivalent reductions in arterial pressure and LVH in male and female SHR when the endogenous RAS is intact. However, inhibition of the RAS reveals a marked sex difference in the responsiveness to AngII both with respect to arterial pressure and cardiac hypertrophic responses. Gaining a greater understanding of sex differences in blood pressure control will ultimately lead to improved antihypertensive cardioprotective therapies for women. R01HL153112-02 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.
Social Anxiety, Academic Self-Efficacy, and Course Performance in Pre-Nursing Students Enrolled in Human Anatomy and Physiology I and II
Authors: Flotte Elizabeth 
Published: May 2023

This study investigates the effects of social anxiety and academic self-efficacy on course structure preference, exam scores, and final grades. The study included 25 students enrolled in accelerated Human Anatomy and Physiology I and II college courses offered consecutively within the Fall 2022 semester. Students were surveyed three times throughout the semester and responses regarding anxiety, self-efficacy, and preference for course structure (lecture-based or active learning instruction) were compared to academic performance. Levels of social anxiety did not seem to affect overall course structure preference or course performance, although students indicated a variety of course activities that cause them anxiety. Students with higher levels of academic self-efficacy, however, displayed increased academic performance. The relationship between academic self-efficacy and performance was strongest on lecture exams with the greatest emphasis on physiology. This study supports the importance of building self-efficacy for success in courses covering complex topics and demonstrates a need to better understand the role of student anxiety. 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.
Loss of tissue inhibitor of proteinase 3 (TIMP3), but not TIMP4, worsens abdominal and thoracic aortic aneurysm
Authors: Hu Mei , Hu Mei , Meganathan Ilamaran , Kassiri Zamaneh 
Published: May 2023

Background: Aorta exhibits regional heterogeneity (structural and mechanical), while different etiologies for thoracic and abdominal aortic aneurysm (TAA, AAA) are recognized. Tissue inhibitor of metalloproteinases (TIMPs) regulate vascular remodeling through different mechanisms. TIMP3 and TIMP4 have shown region-dependent functions in aortic pathologies. We investigated the region-specific function of these TIMPs in development of TAA versus AAA. Methods and Results: TAA or AAA was induced in male or female mice lacking TIMP3 ( Timp3-/-), TIMP4 ( Timp4-/-) or wildtype (WT) mice by peri-adventitial elastase application. Loss of TIMP3 exacerbated TAA and AAA severity in males and females. Timp3-/- mice exhibited a greater increase in proteinase activity, smooth muscle cell phenotypic switching post-AAA and -TAA whereas inflammation increased in the media post-AAA, but in the adventitia post-TAA. Timp3-/- mice showed impaired intimal barrier integrity ( in vivo) following AAA, but a greater adventitial vasa-vasorum branching post-TAA, which could explain the site of inflammation in TAA versus AAA. Timp4-/- mice responded similarly to TAA and AAA induction as the WT. In vitro, Timp3 knockdown in human aortic EC more severely compromised the EC monolayer permeability compared to Timp4 knockdown and control groups following elastase treatment. In human aorta specimens, TIMP3 showed a region-specific expression pattern in TAA versus AAA consistent with the impact of its loss in the impaired intimal barrier in AAA, and the adventitial region in TAA. Conclusions: TIMP3 plays a protective role in both AAA and TAA, whereas loss of TIMP4 has minimal impact on the severity of aneurysm formation. TIMP3 loss in the aneurysmal aorta could be responsible for the inflammation, adverse remodeling and aortic dilation in AAA and TAA, through different mechanisms. Support: CIHR, Heart and Stroke. CIHR, Heart and Stroke. 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.
NCC regulation by WNK/SPAK pathway is influenced by alkalosis
Authors: Al-Qusairi Lama , Shin Ella , Welling Paul 
Published: May 2023

The WNK/SPAK “potassium-switch” pathway provides a homeostatic mechanism that activates the sodium chloride cotransporter, NCC, to limit urinary potassium excretion in dietary potassium deficiency at the expense of increasing salt-sensitivity and blood pressure. Although it is well understood that high dietary potassium turns off the switch, and decreases NCC activity, several reports suggest the counter anion in potassium-rich diets may have an influence on the pathway. The goal of the present study was to determine if the chronic response to a high K diet depends on the counter anion. Wild-type C57BL6J mice were randomized to control (1%K+), potassium chloride (KCl: 5%K+), or potassium bicarbonate (KHCO3: 5%K+) diets, and physiological, molecular, and imaging analyses were performed at 4 and 10 days of diet consumption. In contrast to the classic response to high KCl diet, characterized by reduced NCC phosphorylation and membrane localization, NCC phosphorylation and apical localization increased after 10 days on the high KHCO3 diet. This response was paralleled by increased phosphorylation of the downstream potassium-switch kinase, SPAK, which in turn phosphorylates NCC. Immunofluorescence imaging revealed WNK4 bodies were more numerous and larger in the high KHCO3 group compared to the control, consistent with activation of upstream WNK signaling. Urine excretion studies revealed mice on the high KHCO3 retain more Na+ than mice on control or KCl diets, paralleling enhanced NCC activation. Unlike mice on the high KCl diet, mice on the high KHCO3 diet develop and maintain metabolic alkalosis and do not exhibit profound hyperkalemia, coincident with more robust activation of ENaC and ROMK than with the high KCl diet. In summary, these data identify an unexpected NCC activation mechanism that may limit distal sodium delivery to prevent excessive potassium losses when alkalosis super activates potassium secretion in more distal segments. NIDDK, LeDucq Foundation 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.
Sex-specific differences in the circulatory response to postural stress among young adults with adverse childhood experiences (ACEs)
Authors: Iannarelli Nathan , Wade Terrance , Dempster Kylie , O'Leary Deborah 
Published: May 2023

Adverse childhood experiences (ACEs)—a highly prevalent assortment of traumatic childhood events (e.g., abuse)—are strongly linked to adult cardiovascular disease (CVD), though differently among males and females. Biological sex differences in the circulatory response to physiological stress (e.g., postural stress) have been well-characterized; however, whether ACEs affect this response differently among males and females remains unclear. This study tested the hypothesis that ACEs affect the circulatory response to head-up tilt (HUT; postural stress) differently among males and females. Three hundred ( n = 156 female; 22.4 ± 1.8 years) young adults recruited through the Niagara Longitudinal Heart Study (NLHS) were included in the current analyses. ACEs were assessed (Childhood Trust Events Survey 2.0) and participants were dichotomized into high (≥4 ACEs) and low (<4 ACEs) exposure groups. Beat-by-beat mean arterial pressure (MAP; finger photoplethysmography) and heart rate (HR; electrocardiogram) were recorded during 10-minutes of supine rest and 5-minutes of 60° HUT. Sex-stratified, mixed-model regression analyses assessed the effect of ACEs on changes (Δ) in MAP and HR from supine rest to HUT, adjusting for age, body mass index, physical activity, and smoking status. During HUT, MAP increased to a similar extent in males with high and low ACEs exposure (ΔMAP: 11.5 ± 10.8 mmHg vs. 10.1 ± 10.9 mmHg, respectively; p > 0.05). In contrast, MAP increased to a greater extent in females with high ACEs exposure compared to females with low ACEs exposure (ΔMAP: 11.3 ± 10.4 mmHg vs. 5.9 ± 9.8 mmHg, respectively; p = 0.003). HR increased during HUT in males with both high and low ACEs exposure; however, it increased to a lesser extent in males with high ACEs exposure compared to males with low ACEs exposure (ΔHR: 14.7 ± 7.5 bpm vs. 18.7 ± 8.1 bpm, respectively; p = 0.015). In females, HR increased to a similar extent during HUT in those with high and low ACEs exposure (ΔHR: 16.5 ± 8.1 bpm vs. 17.6 ± 8.9 bpm, respectively; p > 0.05). These data suggest that ACEs affect the circulatory response to postural stress differently in males and females. Further, these data imply that sex-specific differences in circulatory regulation can be observed as early as young adulthood in those reporting high ACEs exposure. This work was supported by the Canadian Institute of Health Research (CIHR) and Brock University 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.