bluuebunny/crossref_metadata_2025 huggingface dataset:
Mesenchymal Stem Cells improve phenotype of induced pluripotent stem cell (iPSC)-derived cardiomyocytes in Hypoplastic Left Heart Syndrome
Authors: Liang Huan-Ling , Anfinson Melissa , Mahnke Donna , Pereckas Michaela , Pan Amy , Tefft Brandon , Lincoln Joy
Published: May 2024

Hypoplastic left heart syndrome (HLHS) is a clinically and anatomically severe form of congenital heart disease (CHD). We previously demonstrated that genetic variants in the alpha myosin heavy chain (MYH6) gene are significantly associated with HLHS as well as poor outcomes in patients. Additionally, induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) carrying an MYH6-R443P head domain variant demonstrated an impaired CM phenotype including dysmorphic sarcomere structure, altered contractility, and upregulated MYH7 expression. Mesenchymal stem cells (MSCs) and their secretome are currently being explored as a potential therapeutic for cardiac injury. In this study, a possible treatment strategy for iPSC-CMs with a MYH6 tail domain variant was examined through investigation of co-culturing umbilical cord tissue derived MSCs from a healthy newborn. iPSC-CMs from an unaffected family member were included as a normal control to compare cellular RNA and protein changes observed in the MYH6-E1584K line. The MYH6-E1584K variant line demonstrated significant upregulation of sarcomere, calcium channel, and inflammation/immune related gene expression in both mRNA and protein levels. Co-culturing with MSCs rescued expression of several genes and was confirmed through label free proteomic analysis. Co-culturing iPSC-CMs with MSCs also significantly improved contraction (contraction maximum displacement and velocity) in MYH6-E1584K iPSC-CMs. Finally, measurements of microRNA, cytokines, and exosomes secreted into cultured media indicated significant changes. This study suggests that MSC secreted factors improve CM expression and function and may elucidate a new mechanistic target for patients with HLHS.

AHW/HHI Innovation Pilot Award.

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.
Consequences of Transient YAP Signaling in the Liver
Authors: Alcedo Karel , Samey Oksanna , Biju Isaac , Sun Liang , Camargo Fernando
Published: May 2024

The transcriptional co-activator YAP plays a complex role in liver homeostasis and disease development. In response to liver injuries and hepatotoxins, YAP is transiently activated to promote liver regeneration by coordinating cell proliferation and metabolism. By contrast, chronic activation of YAP in experimental models has been associated with liver diseases and cancer. These primary responses to YAP are well established; however, it is presently unknown how acute YAP signaling contributes to the eventual development of liver diseases. Here, we developed an in vivo model of dynamic YAP signaling using a doxycycline-inducible system to control the transient expression of a constitutively active YAP mutant in hepatocytes. We found that while YAP-dependent effects on liver growth and cell proliferation are reversible, there are metabolic changes in the liver that remain stable even after YAP inactivation. By coupling RNAseq and ATACseq analyses, we unraveled persistent changes in gene expression and chromatin accessibility, particularly those involved in lipid metabolism. Furthermore, we demonstrated that transient YAP signaling sensitizes the liver to develop more severe liver injuries than normally induced in an unprimed liver. These data suggest that transient YAP signaling imparts a form of lipid metabolic memory that promotes susceptibility to liver diseases. Overall, our current work reveals long-term consequences of acute YAP signaling that may influence the development of liver diseases.

5R01HL128850-07 (FC) and 5T32DK007477-40 (KA).

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.
Impact of modulating pulmonary artery pressure on resting right ventricular function in endurance-trained and untrained individuals
Authors: Brotto Andrew , D'Souza Andrew , Foulkes Stephen , Rampuri Zahrah , Kesslar Keanne , Fuhr Desi , Haykowsky Mark
Published: May 2024

Prolonged endurance training is associated with critical adaptations to right ventricular (RV) structure and function that facilitate the achievement of higher exercise capacity, peak cardiac output, and RV stroke volume in the face of large increases in pulmonary artery pressures (afterload) and RV wall stress. Compared to the left ventricle, the RV is more sensitive to increases in afterload during exercise. However, the independent effect of increased afterload on RV function in endurance trained (Trained) vs untrained individuals remain unknown. Trained were considered those with a maximal oxygen consumption ( V̇O2max) >60ml/kg/min (male) or >55ml/kg/min (female) while untrained were defined as V̇O2max <45ml/kg/min. Using echocardiography, this retrospective study sought to evaluate RV systolic function (RV global longitudinal strain [GLS]) and ventriculo-arterial coupling (ratio of RV GLS to pulmonary artery systolic pressure [PASP]) in Trained and untrained individuals while manipulating PASP. Ten participants (5 Trained and 5 Untrained) underwent resting echocardiography while breathing moderate (pressure of inspired oxygen; PiO2=89 mmHg) and severe hypoxia (PiO2=79 mmHg; order randomized) to increase PASP. Separately, eight participants (4 Trained and 4 untrained) inhaled nitric oxide (iNO; 40ppm) during echocardiography to lower PASP. Moderate and severe hypoxia increased PASP by 2.3 ± 1.3mmHg and 3.5 ± 1.8mmHg, respectively, while iNO decreased PASP by 2.6 ± 2.4mmHg, with no between group differences observed. Cardiac output was not different between any condition. A fitness-by-hypoxia interaction was observed in RV GLS in moderate hypoxia suggesting Trained had lower RV function during moderate hypoxia as compared to untrained (Untrained: -23.1 ± 4.4% vs. Trained: -20.2 ± 2.7%; p<0.01). No differences in RV GLS were observed with iNO (p=0.98). The ratio of RV GLS to PASP was significantly different between groups at moderate hypoxia (Untrained: -1.06 ± 0.09%/mmHg vs. Trained: -0.85 ± 0.12%/mmHg; p=0.04) but not severe hypoxia (p=0.78). These findings suggest reducing PASP did not alter RV function or ventriculo-arterial coupling, however, Trained individuals experienced differential RV function responses when PASP is experimentally increased with hypoxia.

Natural Sciences and Engineering Research Council of Canada.

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.
PERK specific inhibitor AMG-44 protects against Trimethylamine N-oxide (TMAO)-induced Endoplasmic Reticular Stress and Endothelial Dysfunction
Authors: Koka Saisudha , Pasham Sindhura , Boini Krishna M.
Published: May 2024

The gut microbiota is known to release metabolites detrimental to the endothelial cell lining of the vascular wall leading to endothelial dysfunction. We have earlier reported that Trimethylamine N-oxide (TMAO), an intestinal microbe derived metabolite, caused endothelial dysfunction. In the present study we hypothesized that protein kinase R-like endoplasmic reticulum kinase (PERK)/eIF2α/ATF4 signaling is involved in TMAO-induced endoplasmic reticular (ER) stress and that treatment with PERK inhibitor AMG-44 protects against TMAO-induced ER stress. The endothelial cells were treated with a range of increasing doses of TMAO (0-300 μM) to induce ER stress. PERK inhibitor AMG-44 (20 – 200nM) was used to treat the TMAO treated and control cells. TAMO showed a dose-dependent upregulation of ER stress marker proteins involved in the PERK/eIF2α/ATF4 ER-stress signaling pathway. Western blot analysis showed significant increase in p-PERK/PERK, p-eIF2α/eIF2α, and IRE1α, AFT-4 protein expression which was further confirmed by immunofluorescent analysis in endothelial cells. Treatment with AMG-44 significantly attenuated the PERK/eIF2α/ATF4 axis also protected against increased endothelial cell permeability induced by TMAO (n=6/group; p<0.05). Our results demonstrate that TMAO-induced endothelial dysfunction via the ER stress-mediated PERK- eIF2 α -ATF4 signaling pathway and that treatment with PERK specific inhibitor AMG-44 could be a novel therapeutic strategy in protection against TMAO-induced ER stress and endothelial dysfunction.

NIH R01HL148711 to Dr. Sai Sudha Koka.

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.
Freshly isolated bone marrow monocytes from mice lacking βENaC or ASIC2 have sex-linked reduced chemotactic migration responses
Authors: Wasson Robert , McLin Je'la , Hildebrandt Emily , Drummond Heather
Published: May 2024

The monocyte-macrophage system plays an important role in phagocytosis of pathogens and cellular debris following infection or tissue injury. Circulating monocytes differentiate into macrophages which can be polarized into pro- or anti-inflammatory phenotypes. A previous study from our laboratory demonstrated the RAW cell monocyte-macrophage line express α and β Epithelial Na+ Channel (ENaC) subunits which contribute to chemotactic migration and polarization. Here we tested the hypothesis that freshly isolated bone marrow monocytes also express ENaC and related Acid Sensing Ion Channel transcripts which may contribute to monocyte migration. Using qRT-PCR, we found α, βENaC and ASIC1-5 are similarly expressed in freshly isolated bone marrow monocytes from wild-type male and female mice. We also examined chemotactic migration in monocytes isolated from global βENaC hypomorph mice and ASIC2 knockout mice. We found migration was differentially inhibited in male and female animals. In ASIC2−/− monocytes, migration was inhibited to 76±2% and 86±2% of control in male and female animals, respectively. In βENaC hypomorph monocytes, migration was inhibited to 74±2% and 56%±3 of control in male and female animals, respectively. These findings suggest that βENaC and ASIC2 contribute similarly to monocyte migration in males, however, βENaC plays a greater role in migration (than ASIC2) in females. The in-vivo role of βENaC and ASIC2 to monocyte responses associated with inflammation has not been addressed.

This research was supported by NIH R01HL136884, P20GM104357, P30GM149404, P20GM121334, and P20GM103476.

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.
Is improved pulmonary vasodilation why endurance trained individuals have elevated diffusing capacity compared to untrained individuals?
Authors: Ehnes Cameron , Collins Sophie , Brotto Andrew , Fuhr Desi , Thompson Stephanie , van Diepen Sean , Stickland Michael
Published: May 2024

Contrary to our traditional understanding, the pulmonary vasculature may adapt to endurance training. Improved pulmonary vasodilation may be the principal mediator for trained individuals who exhibit greater diffusing capacity (DLCO), capillary blood volume (VC; representing recruitment and distension) and membrane diffusing capacity (DM; representing recruitment) at rest and during exercise as compared to untrained. Potential functional differences may be investigated using pulmonary vasodilators ( e.g., oral sildenafil). The purpose of this study was to examine the effects of sildenafil on DLCO, VC, and DM, in trained and untrained participants. We hypothesized that sildenafil would increase rest and exercise DLCO, VC, and DM, with a lesser relative response in trained due to improved baseline pulmonary vascular function. In this randomized, double-blind, placebo-controlled cross-over design (NCT: 04985929), DLCO was measured at rest (supine and seated) and during cycle ergometry (60 Watts, 30%, 60%, and 90% of V̇O2peak). DLCO was conducted using the modified Roughton-Forster multiple FiO2 breath-hold technique over 6 visits, where participants were given either oral placebo or sildenafil (50 mg, single dose, 30 min wash-in). To date, 18 participants (6 female) (56% target sample size) have been recruited into two groups: trained (T) and untrained (UT) (Mean V̇O2peak = 66.6 ± 7.2 mL.kg−1.min−1 and 37.8 ± 3.2 mL.kg−1.min−1, respectively). Estimated PASP was reduced between placebo and sildenafil across all participants at rest (mean Δ = -2.7 mmHg; p<0.01), indicating effective pulmonary vasodilation. Under placebo, T had higher DLCO at rest (supine), 30%, 60%, and 90% of V̇O2peak (p<0.05), consistent with previous literature. There was no effect of sildenafil on DLCO, VC, or DM (all p>0.200) or drug by workload interactions (all p>0.189) in either group. These preliminary results suggest that pharmacological augmentation of the nitric oxide vasodilatory pathway does not increase DLCO regardless of training status. We speculate that this pathway may not be the primary driver responsible for the elevated DLCO observed in endurance trained participants.

Natural Sciences and Engineering Research Council of Canada.

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.
Hypoxia impairs Kv7 channel function in the coronary microcirculation
Authors: Self Trevor , Heaps Cristine
Published: May 2024

Ischemic heart disease (IHD) is a multifaceted pathological manifestation that continues to press an extensive burden on individuals and healthcare resources. The strenuous weight of this disease affects more than 80 million people in the United States, with an annual economic cost of more than $300 billion in healthcare expenses and lost productivity. Understanding the progression of this disease and the underlying regulatory mechanisms is essential for dampening the substantial socio-economic burden it poses by supporting the development of novel therapeutic strategies for afflicted patients. Myocardial perfusion is largely controlled by the microcirculation, consisting of small arteries and arterioles. Under physiological conditions, an increase in myocardial metabolic activity stimulates coronary vasodilation and increased vascular perfusion. However, pathological coronary stenosis of the conduit arteries impairs downstream flow and O2 delivery that must be compensated by collateral supply from neighboring nonoccluded regions. The ability of the vasculature to dilate in response to a reduction in flow is paramount for improved perfusion from the collateral circulation. Voltage-gated potassium (Kv) channels present as significant end effectors of vasodilation for many signaling axes, including reactive oxygen species, which are reported to be upregulated under ischemic conditions. Using the clinically relevant swine model for the current study, we isolate a reduction in oxygen tension, ex vivo, as a single characteristic of an otherwise complicated disease and test the hypothesis that hypoxic insult impairs Kv7 channel function. Isometric tension wire myography and perforated patch voltage clamp were used to investigate Kv7 channel contribution to H2O2-mediated vasodilation and Kv channel currents in response to hypoxic insult. Our data reveal that hypoxic conditions impair H2O2-mediated vasodilation and that this impairment is attributable, at least in part, to a loss of Kv7 channel activation. Further, protein kinases are known to associate with and activate Kv7 channels in other tissue types. Inhibition of protein kinase A (PKA) yields a similar inhibitory response to blockade of Kv7 channels. Taken together, these studies reveal Kv7 channels as potential targets of hypoxic insult, and their reduced contribution may be responsible for impaired vasoreactivity in the coronary microcirculation in response to hypoxic insult.

Funding: NIH RO1 HL139903.

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.
Age Comparisons of Cardiac Work During Exercise in Women: Insight from Acute β1 Adrenergic Blockade
Authors: Bowlus Christine , Studinski Matthew , Delgado Spicuzza Jocelyn , Gosalia Jigar , Pawelczyk James , Muller Matthew , Mookerjee Swapan
Published: May 2024

Postmenopausal women exhibit exaggerated increases in blood pressure during activities of daily living and exercise. The decreased size and increased stiffening of postmenopausal women's hearts elevate myocardial oxygen demand when compared to age-matched men and younger cohorts. Together, this poses a risk to the safety of, and capacity for, exercise in postmenopausal women. We recently studied the effects of esmolol, a fast-acting, cardio-selective β1 antagonist, on oxygen transport variables during dynamic exercise in healthy young (Y) and older (O) women to better understand differences in cardiovascular responses to exercise. Objective: Determine the effects of acute cardiac specific blockade on myocardial oxygen demand (rate pressure product, RPP) and cardiac work (CW) in healthy young premenopausal and older postmenopausal women. Methods: Thirteen healthy young (20-32 yr) and older postmenopausal (58-70 yr) women performed moderate (85% of lactate threshold) and heavy (50% between lactate threshold and the respiratory compensation point) recumbent leg cycling exercise during IV infusion of saline or esmolol in randomized order. Whole body oxygen consumption (VO2, indirect calorimetry), brachial systolic blood pressure (SBP, automated cuff), heart rate (HR, ECG), and cardiac output (CO, bioimpedance) were measured continuously. RPP (HR×SBP), CW (CO×SBP), and cardiac effciency (CE, CW/VO2) were calculated. Mixed model repeated measures ANOVAs were used to determine the effect of treatment and age group. Results: Power outputs were lower in O vs. Y at both moderate (45±9W and 72±15W, p<0.001) and heavy (81±21W vs. 117±32W, p<0.001) intensities. During the saline trial CO was lower (p<0.001), and RPP was higher (p<0.001) in the O vs. Y group during both intensities. There was a main effect of treatment on RPP, CW, and CE. Esmolol reduced RPP (4638±775 SD, p<0.001), CW (547±89, p<0.001) and CE (1682±62, p<0.001) in both O and Y. There was a main effect of age group on CE, pairwise comparisons showed CE was lower in O than Y (441±112, p<0.001). Conclusions: Older postmenopausal women experience higher myocardial oxygen demand and perform more cardiac work for a given whole body liter oxygen consumed during dynamic leg exercise compared to younger premenopausal women. Acute β1 adrenergic blockade narrows the gap between central cardiovascular function in young and old women and provides a powerful tool to investigate age-related cardiovascular differences.

NIH R21 AG054940.

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.
Deletion of Irisin Mitigates HDAC4 Inhibitor-Elicited Protective Effect in Hemorrhage
Authors: Kulthinee Supaporn , Zhang Ling , Wang Lijiang , Zhao Ting
Published: May 2024

Introduction: Histone deacetylate inhibition contributes critically to modulating insulin resistance and cardiovascular function. It remains unknown whether inhibition of specific HDAC isoform 4 could improve cardiac function and attenuates inflammatory response and whether HDAC4 inhibition-induced protection is related to irisin. The objective of this study is to investigate whether HDAC4 inhibition induced protective effect against hemorrhage-induced detrimental effects would be diminished by deletion of irisin. Method: Irisin knockout (irisin−/−) mice was generated by using the CRISPR/Cas-9 genome-editing system. Hemorrhage was induced in mice by achieving a mean arterial blood pressure of 35-45 mmHg for one hour, followed by two hours of resuscitation. Experimental groups were divided as followings: I) Wild type (WT)+Hemorrhage (control) (N=7): WT mice were subjected to hemorrhage for 60 minutes followed by resuscitation; II) NVS-HD-1+Hemorrhage (n=7): The same as the group I except that NVS-HD1, a selective HDAC inhibitor (3mg/kg) was infused during resuscitation; III) Irisin −/− +Hemorrhage (n=6): Irisin −/− mice underwent hemorrhage and resuscitation; IV) NVS-HD-1 + Irisin−/−+Hemorrhage (n=6): The same as the groups III except that NVS-HD-1 was given to Irisin −/− during resuscitation. Myocardial function and hemodynamics were assessed using echocardiography and femoral artery catheterization, respectively. Cytokine releases from serum were measured using Enzyme-linked immunosorbent assay (ELISA). Histological assessment was performed to determine tissue damage in both myocardium and skeletal muscles. TUNEL was carried out to assess apoptotic signal in tissues. Results: As compared to control group, HDAC4 inhibitor significantly improved the cardiac function and recovery of hemodynamics, which was associated with the decreased release of IL6 and TNF-α in hemorrhage. The infiltration of inflammatory cells and TUNEL positive apoptosis in muscles were mitigated by inhibition of HDAC4. However, HDAC4 inhibitor-induced myocardial protection and suppression of inflammation against hemorrhage was lost by genetic deletion of irisin. Conclusion: Selective inhibition of HDAC4 produced protective effects with an improvement in myocardial function and attenuation of inflammation against hemorrhage, which is dependent on irisin.

The work is supported by the National Institute of General Medical Sciences (R01GM 141339), United States; the National Heart, Lung, and Blood Institute Grants (R01 HL089405), United States.

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.
Alteration of the bile acid pool attenuates neuroinflammation in the EAE mouse model of Multiple Sclerosis
Authors: Comiskey Shane , Qazi Aisha , Calzadilla Nathan , Eathara Abhijith , Natarajan Anbazhagan Arivarasu , Saksena Seema , K Dudeja Pradeep
Published: May 2024

Bile acids are critical signaling molecules that mediate gut crosstalk with other organs, including the brain. The primary bile acids, such as chenodeoxycholic acid (CDCA), are synthesized in the liver and modified by gut bacteria to generate secondary bile acids like the 12α-hydroxylated deoxycholic acid (DCA). Bile acids are effciently absorbed in the distal ileum, and recent studies have implicated them in neuroinflammation and the pathophysiology of several neurological diseases such as Multiple Sclerosis (MS). However, the specific effects of different types of bile acids on MS have not been thoroughly investigated. We hypothesize that bile acids differentially affect neuroinflammation and that treatment with cholestyramine (bile acid sequestrant) modulates astrocyte activation in a mouse model of MS. Methods: Primary astrocyte cultures were prepared from 6-10-week-old C57BL/6 mice and incubated with cytokines in the presence and absence of bile acids. The expression of inflammatory and astrocyte activation markers was assessed by real-time qPCR. The effects of blocking bile acid absorption on MS were examined using the established Experimental Autoimmune Encephalomyelitis (EAE) mouse model of MS in 8-week-old female mice (C57BL/6). Mice were fed either a standard chow diet or a standard chow diet supplemented with 2% cholestyramine, a bile acid sequestrant, to block bile acid absorption. Statistical significance between groups was determined by an unpaired T-test. Results: Astrocytes treated with cytokines (TNF-α, 10 ng/mL, IL1-β, 10 ng/mL, 24 h) significantly increased the mRNA expression of TNF-α and IL1-β and markers of astrocyte activation, lipocalin 2 (LCN2), and Serpina3n. Co-treatment with cytokines and CDCA but not DCA (50 μM, 24 h) significantly decreased TNF-α (~56%, p<0.01), IL1-β (~40%, p<0.01), LCN2 (~26%, p<.001), and Serpina3n (~44%, p<.001), vs cytokines alone. The taurine-conjugate, TCDCA, also resulted in significant decreases in the expression of TNF-α (~72%, p<0.001), IL1-β (~53%, p<.001), LCN2 (~30%, p<0.05), and Serpina3n (~16%, p<0.01), suggesting an anti-inflammatory effect specific to CDCA and its taurine conjugate on astrocytes. Cholestyramine treatment in EAE mice was associated with significant reductions in the mRNA expression of TNF-α (~40%, p<0.05) and Serpina3n (~30%, p= 0.217) in the frontal cortex of the brain. Together, these data imply that altering the composition of the bile acid pool may be a viable therapeutic strategy for MS patients by attenuating neuroinflammation.

University of Illinois at Chicago, JBVMC, Chicago, IL.

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.
Luminal flow-stimulated superoxide participates in connecting tubule-glomerular feedback
Authors: Romero Cesar , Wang Hong , Ortiz Pablo
Published: May 2024

Increasing NaCl concentration in the connecting tubule (CNT) dilates the afferent arteriole (Af-Art) through the connecting tubule-glomerular feedback (CNTGF). CNTGF is mediated by Na+ transport via epithelial Na+ channels (ENaC) in the CNT. It is unknown if CNTGF is mainly activated by NaCl concentration or sodium delivery or if there is an independent luminal flow effect. Previous studies showed that luminal flow stimulates superoxide (O2−), and O2− can activate ENaC. Thus we hypothesized that increasing luminal flow in the CNT induces CNTGF via O2− generation and ENaC activation. Rabbit Af-Arts with the adjacent CNTs were microdissected and perfused in vitro. Protocols consist of two consecutive dose-response curves to flow rate in the same preparation. When the CNT was perfused with 5mM NaCl, increasing flow rates from 5 to 10, 20, and 40 nL/min caused flow rate-dependent Af-Art dilatation (p<0.01). Adding an ENaC blocker benzamil to the perfusate blocked flow-induced Af-Art dilatation, indicating a CNTGF response. Using mathematical modeling, an increased tubular flow controlled by NaCl delivery into the CNT independently increases CNTGF vasodilation. However, when CNT was perfused with 0 mM NaCl, increasing the flow rate did not induce CNTGF vasodilation. The O2− dismutase mimetic tempol reduced flow-induced CNTGF. In the presence of L-NAME (NOS inhibitor), the reduced CNTGF mediated by tempol was unaffected. We concluded that increasing luminal flow in CNT induces CNTGF activation via ENaC, partly due to flow-stimulated O2− production and independently of NOS.

1K01HL155235.

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.
Colostrum Supplementation to Rescue Antibiotic-Induced Dysbiosis and Reduce Long-Term Obesity Risk
Authors: Antunes Karen , Leathem Cameron , Mims Tahliyah , Willis Nathaniel , Pierre Joseph
Published: May 2024

The prevalence of metabolic disease in the United States has increased from 30.4% to 41.9% in the past decades, with rising rates among children. Emerging evidence implicates intestinal microbiome function as contributing to metabolic disease risk, with dysbiosis being associated with overweight and obese status. While sometimes lifesaving, antibioticssuch as azithromycin cause microbiota ecological instability and are significantly associated with a greater risk ofmetabolic disease and obesity in children. Since antibiotics are often necessary, the identification of nutritional interventions to restore microbial membership and function has a high potential value for millions of patients. Colostrum is the first milk produced by mammals immediately after birth and shapes intestinal colonization patterns, specifically enriching Bifidobacterium, Lactobacillus, and limiting the colonization of Proteobacteria. Bovine colostrum containsimmunomodulators, lactoferrin, oligosaccharides, bioactive compounds, and macronutrients. The compounds are similar across mammalian species. Considering the impact of colostrum in the sterile early-life gut, we hypothesized that bovine colostrum provided as a supplemental nutraceutical therapy would augment gut microbial recolonization following antibiotic exposures and mitigate long-term metabolic consequences. Specific pathogen-free (SPF) C57BL/6 mice (male, three weeks old, Jackson Laboratory) were housed under standard laboratory conditions with a 45% high-fat diet. Tylosintartrate antibiotic (ABX) was administered to some mice in drinking water 3 days/week over three weeks, with four days washout/week. To examine colostrum, some animals were provided colostrum gavage during or immediately following ABX exposures. After intervention, body composition and metabolic phenotypes were monitored for 16 weeks.Compared with ABX alone, colostrum following ABX maintained similar body composition and glucose tolerance as controls, while colostrum during ABX appeared similar to ABX alone. Examination of the gut microbiome showed unique enrichment of Akkermansia and Sutterella with decreased Enterobacteriaceae in mice treated with ABX followed by colostrum. Analysis of the gut mucosa demonstrated ABX decreased goblet cell numbers per villi (7.2/villus) compared with control (9.8/villus), and colostrum following ABX elevated goblet cells (8.6/villus). These data suggest colostrum may stimulate epithelial responses that foster host-microbial symbiosis at the mucosal surface and play a role in intestinal recolonization to benefit long-term homeostasis.

Dairy Innovation Hub, UW-Madison.

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.
Novel role of dual oxidase 2 as a mediator of podocyte injury in the diabetic environment
Authors: Ybarra Seleste , Marsh Megan , Hecker Jacqueline , Castro Aracely , Ford Bridget
Published: May 2024

Glomerular injury is a prominent pathological feature of diabetic nephropathy (DN). In glomerular epithelial cells, or podocytes, hyperglycemia alters slit diaphragm proteins and causes foot process effacement, apoptosis and cell detachment. Oxidative stress has emerged as an important pathogenic mechanism in the development of glomerular injury in DN. However, the mechanisms by which these factors exert their action remain poorly understood. We provide evidence that the NADPH oxidase of the Nox family, Dual oxidase 2 (Duox2), is present in cultured glomerular cells, including podocytes. Exposure of cultured podocytes to high concentrations of glucose (HG) elicited a rapid upregulation of Duox2 protein expression. Inhibition of Duox2 with specific siRNA prevented the HG-induced increase in intracellular reactive oxygen species (ROS) generation and hydrogen peroxide (H2O2) production in cultured podocytes. In additional experiments, we established a functional link between Duox2-derived ROS generation and podocyte injury in response to HG. Impairment of Duox2 function nearly abolished HG-mediated DNA fragmentation, apoptosis and decrease in/reorganization of slit diaphragm protein expression in podocytes, indicating that Duox2 is required for the deleterious effects of glucose in podocytes. Our study demonstrates, for the first time, that Duox2 is responsible for increased ROS generation and subsequent alteration of podocyte function in response to HG. Our work serves as proof of concept to demonstrate the utility of targeting Duox2 as a future therapeutic intervention to reduce diabetes-mediated glomerular lesions.

Research reported in this poster was supported by the University of the Incarnate Word Offce of Research and Graduate Studies and the National Institute of General Medical Sciences of the National Institutes of Health under Award Number SC2GM136569. The content is solely the responsibility of the authors and does not necessarily represent the offcial views of the National Institutes of Health.

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.
Beta-Adrenergic Signaling Induces Arrhythmias and Cardiac Dysfunction in Paclitaxel-Treated Mice
Authors: Gaul-Muller Kelli , Thomas Andrew , Contreras Jorge
Published: May 2024

In the past two decades, chemotherapy-related cardiac dysfunction (CRCD) has emerged as a dangerous complication in cancer survivors. Despite recent advancements, the mechanisms underlying the development and progression of CRCD remain poorly understood. Paclitaxel (PTX), an antimicrotubular agent, is known to produce dysrhythmia in 29% of patients when used as monotherapy. Since cardiac stress via β-adrenergic signaling is known to exacerbate arrhythmias, here we examine the action of a single isoproterenol (ISO) injection in wild-type mice treated with low and high therapeutic doses of PTX (8mg/kg and 12.5mg/kg, respectively). Male mice were treated with 4 intraperitoneal (IP) injections of PTX or vehicle (1:1:4 ratio of ethanol: Kolliphor: saline) per week for 4 weeks and a remote telemetry device was surgically implanted. Following treatment, mice were challenged with one IP injection of 5mg/kg ISO and ambulatory electrocardiography was performed. Over the course of PTX treatment, low- and high-dose PTX-treated mice displayed significant weight loss compared to vehicle-treated mice (-9.65% vs -0.52%, p=0.0018 and -10.99% vs 0.93%, p=0.0016, respectively). While low-dose PTX-treated mice did not show statistically significant differences in heart weight to body weight ratio compared to vehicle-treated mice (5.56mg/g vs 5.16mg/g, p=0.14), high-dose PTX-treated males showed increased cardiac hypertrophy compared to vehicle-treated mice (5.20mg/g vs 4.89mg/g, p=0.081). Prior to ISO challenge, there was no difference in arrhythmia severity between groups (0.0 vs 0.0, p=0.45 and 0.0 vs 1.0, p=0.99). One hour following ISO challenge, all mice treated with either a low or high dose of PTX showed higher arrhythmia severity than vehicle-treated mice (4.0 vs 2.5, p=0.0087 and 4.0 vs 3.0, p=0.0079, respectively). Additionally, low and high-dose PTX-treated mice experienced more atrioventricular block than vehicle-treated mice in the first hour following ISO challenge (9.17 vs 0.67, p=0.01 and 4.0 vs 1.0, p=0.06, respectively). After 24-hours, differences in arrhythmia severity returned to baseline (0.5 vs 1.0, p=0.99 and 1.0 vs 0.0, p=0.4). Our data indicates that chronic treatment of male mice with therapeutic levels of PTX predisposes to cardiac stress-induced atrial arrhythmias. This finding might have important implications for the treatment of CRCD.

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.
Fasting identifies SLIT2 as a novel driver of doxorubicin cardiotoxicity
Authors: Ozcan Mualla , Valenzuela Ripoll Carla , Lotfinaghsh Aynaz , Guo Zhen , Diab Ahmed , Ataran Anahita , Hajirezaei Hamid
Published: May 2024

Intermittent fasting strategies, including alternate day fasting (ADF), may attenuate aging phenotypes and reduce cardiovascular risk in part by stimulating brown adipogenesis. However, in the setting of cardiotoxic doxorubicin (Dox) chemotherapy, we recently described a novel toxicity of sustained ADF, which stimulated cachexia and cardiac atrophy in mice. Presently, we tested the effect of fasting initiated after Dox chemotherapy and found that fasting caused a decline in lean body mass and left ventricular mass index, but increased body fat content, liver weight, and brown adipose tissue (BAT) weight index vs Dox-treated mice. Dox + ADF induced SLIT2, which regulates thermogenesis and metabolic function in BAT. Dox plus recombinant SLIT2 decreased left ventricular ejection fraction vs Dox alone. Plasma proteomics from patients showed that SLIT2 was the top protein associated with Dox cardiomyopathy vs other non-ischemic cardiomyopathy. This study suggests that SLIT2, an activator of brown adipogenesis, is a novel driver of Dox cardiotoxicity.

This research was supported by NIH (R01HL155344, K08HL138262, P30DK056341, P30DK020579), Children's Discovery Institute of Washington University and St. Louis Children's Hospital (MC-FR-2020-919), and Longer Life Foundation.

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.
Our undergraduate program for physiology research, UPRIME (Undergraduate Physiology In Medicine and Education) will continue and further encourage and foster our majors in Human Physiology to enter careers in the health professions and physiology research
Authors: Wu Steven , Barnett Vincent , Anderson Lisa
Published: May 2024

We previously announced and reported on our undergraduate summer research program, UPRIME, funded by an American Heart Association Grant with departmental support, has been successful in the fostering of junior and senior undergraduates (UPRIME Scholars) for the health professions and research. UPRIME is a 13-week summer program that provides opportunities for biomedical research, educational support and career advising. Our hope is that this holistic approach builds a space for inclusive excellence in which UPRIME scholars can acquire the tools needed for success. During the past three years, we have selected UPRIME Scholars based on the strength of their applications. We have matched the research interests of the students with our departmental strengths and met with the scholars weekly to foster a peer-based community and augment their research efforts with scientific seminars and discussions. Additionally, our UPRIME Scholars were supported to present their work at local and national level meetings. Our companion program, INPUT (INtegrative Biology & Physiology Undergraduate Training) which is designed for freshmen and sophomores with strong interest in physiology, is also part of our department’s commitment to inclusive excellence. Here, we are updating the statuses of previous and current UPRIME Scholars. Previous UPRIME Scholars have graduated and entered either professional schools (including medical and dental) or continue to work in our research labs. In addition, our most recent 2023 UPRIME Scholars that will graduate between 2023 and 2024 are currently still working in their mentors’ labs. Our department will continue to support UPRIME. In addition, we are committed to expanding our program to the regional and national levels. We seek highly motivated applicants from around the nation to apply to UPRIME for the opportunity to gain meaningful experiences in physiology research.

American Heart Association.

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.
Placental IL-1β inhibits PKM2 and leads to endothelial barrier injury in preeclampsia
Authors: Li Qinghua , Su Hang , Liu Xinlu , Huang Haiqin , Lv Xin , Yang Weiwei
Published: May 2024

Preeclampsia, a life-threatening hypertensive disorder of pregnancy, continues to be a major global health concern. Maternal endothelial dysfunction induced by components from the impaired placenta is a key hallmark of preeclampsia (PE). Increased levels of IL-1β have been observed in preeclamptic placentas, but its association with endothelial dysfunction has remained uncertain. Our hypothesis was that IL-1β released from the placenta links the placental abnormalities with maternal endothelial dysfunction in PE. Our investigation revealed elevated levels of IL-1β in preeclampsia placentas, which were negatively correlated with reduced VE-Cadherin expression in endothelial cells, indicating consistent endothelial dysfunction. Moreover, we identified the glycolytic enzyme pyruvate kinase 2 (PKM2) as a key regulator of glycolysis involved in the regulation of junctional VE-Cadherin in endothelial cells. Rescue assays further demonstrated that the overexpression of PKM2 was necessary to ameliorate endothelial barrier injury induced by IL-1β. Our study provides novel insights into the molecular mechanisms driving preeclampsia, highlighting the regulatory roles of IL-1β, PKM2, and VE-Cadherin in endothelial cells. These identified interactions may play a crucial role in the pathogenesis of preeclampsia, offering potential targets for therapeutic interventions to preserve endothelial integrity and alleviate the condition.

This project was funded by Natural Science Foundation of Shandong (ZR2022MH195 and ZR2023MH211), and the Graduate Student Research Grant from Weifang Medical University.

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.
Knock out of ELAVL1 affects steroid synthesis in adrenocortical carcinoma cell line NCI-H295R and leads to a less malignant phenotype
Authors: Brandau Max , Chernyakov Dmitry , Sbiera Silviu , Landwehr Laura-Sophie , Edemir Bayram
Published: May 2024

Introduction: Adrenocortical carcinoma (ACC) is a rare malignancy of the adrenal gland. With a 5-year-survival rate below 50% and no curative treatment options in advanced stages new therapeutic options in ACC are needed. Analyzing the ACC cohort of the cancer genome atlas we found a significant negative correlation of the expression level of a gene called Embryonic Lethal Abnormal Vision Like 1 (ELAVL1) and ACC patient survival. ELAVL1 has been described to be unfavorable in a lot of different tumor entities, but its function in ACC progression is still unknown. Methods: To evaluate the function of ELAVL1 in ACC progression we performed a CRISPR/Cas9 mediated knock out (KO) of the ELAVL1 gene in the ACC cell line NCI-H295R. The KO was confirmed on DNA level via Sanger sequencing and on protein level via immunofluorescence and western blot. Transcriptome changes were analyzed by next generation RNA sequencing (NGS). To characterize changes in cell function we performed soft agar colony forming assays and evaluated changes in steroid production via mass spectrometry. Results: Via CRISPR/Cas9 we knocked out ELAVL1 in NCI-H295R cells. NGS data showed 6926 significantly deregulated genes in ELAVL1-KO cells compared to control cells. There was an upregulation of 3468 genes, while 3458 genes showed a lower expression in ELAVL1 KO cells. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses showed a significant upregulation of 29 genes associated with aldosterone synthesis and a significant downregulation of 87 genes associated with pathways in cancer. Analyzing cell function via soft agar colony forming assays an impaired colony forming ability in ELAVL1 KO cells was seen. Furthermore, we could prove significant changes in steroid production. ELAVL1 KO led to an inhibition of androgen and glucocorticoid synthesis and an enhancement in mineralocorticoid synthesis. These changes could not only be proven by measuring steroid concentrations in cell culture supernatants, but also by NGS showing a downregulation of the genes CYP17A1 and CYP11B1 and an upregulation of CYP21A2 and CYP11B2. Conclusion: Our study showed that ELAVL1 affects the regulation of around 7000 genes in the ACC cell line NCI-H295R. Especially the inhibition of glucocorticoid synthesis shows that ELAVL1 may be a new target for therapeutic approaches in ACC treatment since hypercortisolism is one of the main symptoms in ACC and a negative prognostic factor for patient survival.

The authors have nothing to disclose.

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 pituitary adenylate cyclase-activating polypeptide neurons in the hypothalamic ventromedial nucleus and the cognate PAC1 receptor in the regulation of hedonic feeding
Authors: Sayers Sarah , Le Nikki , Wagner Edward
Published: May 2024

We explored the role of pituitary adenylate cyclase-activating polypeptide (PACAP) neurons in the hypothalamic ventromedial nucleus (VMN) in regulating hedonic feeding. We hypothesized that VMN PACAP neurons would inhibit reward-encoding mesolimbic (A10) dopamine neurons and thereby suppress impulsive consumption brought on by intermittent exposure to highly palatable food. Visualized whole-cell patch clamp recordings coupled with in vivo behavioral experiments were utilized in wildtype, PACAP- cre, TH- cre and TH- cre/PAC1 receptor-floxed mice. We found that optogenetic stimulation of VMN PACAP neurons inhibited postsynaptic targets in the ventral tegmental area (VTA), an effect replicated by bath application of exogenous PACAP during recordings from preidentified A10 dopamine neurons. These inhibitory actions were abrogated by the PAC1/VPAC2 receptor antagonist PACAP6-38, the KATP channel blocker tolbutamide, and by selective knockdown of the PAC1 receptor in A10 dopamine neurons. PACAP delivered directly into the VTA decreases binge feeding accompanied by reduced meal size and duration. These effects are negated by PACAP6-38, PAC1 receptor knockdown in A10 dopamine neurons, and apoptotic ablation of VMN PACAP neurons. These findings demonstrate that VMN PACAP neurons blunt impulsive, binge feeding behavior by activating PAC1 receptors and KATP channels to inhibit A10 dopamine neurons. As such, they impart impactful insight into potential treatment strategies for conditions such as obesity and food addiction. Work funded by PHS grant DA024314.

Work funded by PHS grant DA024314.

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.