bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of carbohydrate source in a higher protein diet on body weight, body composition, and metabolic health outcomes in adults at risk for type 2 diabetes
Authors: Thomas Ada-Miette , Hayat Mariya , Boudrey Sydney , Hawley Aubrey , Baum Jamie
Published: May 2023

Objective: The objective of this study was to determine the impact of carbohydrate source in higher protein diets on body composition and markers of metabolic health in adults at risk for type 2 diabetes. We hypothesized that carbohydrate source would not impact body composition or markers of metabolic health. Methods: Male and female participants between the ages of 25 and 50 years old were recruited to participate in this 16 week, randomized, controlled, parallel design study (n=21; 14 females and 7 males; age 35.5 ± 10.5). To qualify participants had meet the following criteria: two or more characteristics of metabolic syndrome (body mass index (BMI) > 25, abdominal obesity, triglyceride level over 150 mg/dl, HDL cholesterol < 40 mg/dl in men and 50 mg/dl in women, systolic blood pressure of 130 mm Hg or diastolic blood pressure of 85 mm Hg, and/or fasting glucose > 100 mg/dL) and were consented to participate in this study. Participants were randomized to one of two treatments groups: 1) higher protein diet containing white potatoes (WP; n=11) or 2) higher protein diet with starch carbohydrate (SC; n=10). All diets were isoenergetic within individual participants. Energy content for weight maintenance per individual was calculated using the Harris Benedict equation x 1.35. Each participant was instructed to follow a macronutrient ratio of 30% protein, 30% fat, and 40% carbohydrates. Body composition was measured via DXA at baseline and 16 weeks. Biomarkers of metabolic health were measured at baseline, 4, 8, 12, and 16 weeks. Ethical approval for this study was obtained from the Office of Research Compliance Institutional Review Board of the University of Arkansas (Fayetteville, AR). This study was registered at clinicaltrials.gov (NCT03935048). Written consent was obtained from all participants prior to beginning the study. Results: There was no effect of carbohydrate source on fasting total cholesterol, HDL cholesterol, LDL cholesterol, triglycerides, glucose, or blood pressure after 16 weeks of dietary intervention. There was a significant effect of time and diet (p<0.05) on body weight (WP:-2.06±4.62; SC: +2.90±6.20 lbs) and an effect of diet on (p<0.05) on BMI (WP: -0.39±0.74; SC: 0.42±1.06). Participants following SC had increased loss of fat mass and an increase in fat-free mass compared to WP, but this change was not significantly different. Conclusion: Preliminary data suggests that carbohydrate source in a higher protein diet may influence body composition with no effect on biomarkers of metabolic health.

Alliance for Potato Research and Education

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.
Viral infections such as SARS-CoV-2, HIV, and EBV can alter nonsense-mediated decay and impact cellular processes unique to an individual's genome
Authors: Prokop Jeremy , Palo Anna , Mitchell Jackson , Cook Taylor , Bupp Caleb , Rajasekaran Surender , Chesla Dave , Hartog Nicholas
Published: May 2023

Throughout the last few years, understanding the physiological mechanisms to viral infections has highlighted individuals' unique outcomes. While SARS-CoV-2 and other pathogens can cause hospitalization and mortality, some individuals remain asymptomatic, and others will suffer from years of altered diverse physiological pathways (such as long COVID). Our team, through transcriptomics, has built a hypothesis that many of the individual-level responses are due to the interaction of a virus with a process known as nonsense-mediated decays (NMD) and how suppression of NMD interacts with an individual's genomic variants to drive diverse physiological response. This hypothesis has been built on nearly five hundred clinical transcriptomes of infants with RSV infection, newborns with genomic disorders, kids with multiple organ dysfunction syndrome, and adults with hospitalized COVID-19 paired with >16,000 publicly deposited blood transcriptomes of broad pathologies. Several virus interactions with human genomics have been observed within our work. First, a patient with EBV had an acute activation of viral-induced genetics through suppression of NMD, resulting in elevated RNASEH2B dominant-negative human protein resulting in Hemophagocytic lymphohistiocytosis (HLH), a mechanism of a rare transient disorders. Second, we have observed multiple individuals with viral infections that resulted in either the activation or suppression of interferon cascades correlated to common variant alleles altered by NMD changes, such as ISG15 and cytokines. Third, we show that several of these cytokine modulation genetics can elevate the risk of NMD-regulated Neutrophile Extracellular Trap (NET) production associated with long-term endocrine and hemodynamic modulation. Finally, we show that when a virus suppresses NMD (SARS-CoV-2, HIV, EBV), multiple individuals with latent infections can have an elevation of the dormant virus transcripts, including EBV and Torque teno virus. Thus, individuals can have multiple viruses activated that change physiological outcomes simultaneously. Overall, it is essential to physiology and medicine to refine each individual's precision and unique outcomes based on the complex interaction of a virus with NMD and genomic variants to modify cellular, systems, and inflammatory responses.

This research was funded by the Gerber Foundation, National Institutes of Health (K01ES025435 and R01AI171984), Michigan Department of Health and Human Services, and Michigan State 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.
TRPC6 deficiency impairs middle cerebral artery myogenic response and brain spatial memory
Authors: Wang Zhen , Zhang Huawei , Fan Fan , Sears Jaylan , Fu Yiling , Dai Xuemei , do Carmo Jussara , da Silva Alexandre , Mouton Alan , Omoto Ana , Li Xuan , Hall John
Published: May 2023

Transient receptor potential channel 6 (TRPC6) is a nonselective cation channel belonging to the TRP ion channel family and expressed in vascular smooth muscle cells. TRPC6 regulates calcium influx in response to vascular wall mechanical stretch. A previous study reported that TRPC6 is critical for the myogenic response of the middle cerebral artery (MCA). Impaired MCA myogenic response is implicated in cerebral blood flow dysfunction and may promote cognitive deficits. In this study, we investigated whether TRPC6 contributes to the MCA myogenic response at pressure range (from 40 to 180 mmHg) in 12-week-old male wild-type (WT) and whole-body TRPC6 knock-out (TRPC6 KO) mice (n=5-8). Cognitive function (spatial learning and reference memory) was examined at 22 weeks of age using the Morris water maze test. Myogenic response in MCA was similar in WT and TRPC6 KO mice when perfusion pressure was increased from 40 to 80 mmHg. At higher pressures (>120 mmHg), however, TRPC6 KO mice displayed significantly reduced myogenic response compared to WT mice (3 % less of myogenic tone in TRPC6 KO compared to WT) which was further exacerbated when perfusion pressure was increased to 180 mmHg (9 % less of myogenic tone in TRPC6 KO compared to WT). There were no significant differences in wall thickness, wall-to-lumen ratio, vascular distensibility, incremental distensibility, or elastic modulus curves in MCA between WT and TRPC6 KO mice. Compared to WT mice, TRPC6 KO mice displayed similar spatial learning curves after 4 days of training but showed significantly impaired reference memory (14±1 % vs 29±4 % in the target quadrant) and reduced frequency (1.0±0.3 vs 2.1±0.4 in the target area crossing) compared to WT. These findings suggest that TRPC6 deficiency impairs myogenic response at higher perfusion pressures and spatial memory, even at a young age.

(AG050049 (F.F), AG057842 (F.F), AG079336 (F.F), NIDDK R00DK113280, R01DK121411, NIGMS P20GM104357 and NIGMS U54GM115428)

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.
Changes in DNA methylation patterns during high-altitude acclimatization
Authors: Frost Shyleen , Pham Kathy , Heinrich Erica
Published: May 2023

High altitude is a physiologically stressful environment, in part due to reduced atmospheric oxygen pressure leading to hypoxemia. While the physiological changes that occur during acclimatization to high altitude are well characterized, it is unknown what role epigenetic gene regulation may play in these processes. Therefore, the objective of this study was to measure global changes in DNA methylation in response to acute high-altitude exposure, as well as changes in key hypoxia-inducible factor (HIF) pathway genes including EPAS1[E1] (HIF-2α) and EGLN1 (PHD2). Previous studies suggest that EPAS1 and EGLN1 may play key roles in high-altitude adaptation by promoting erythropoiesis, angiogenesis, and modulating metabolic pathways. We hypothesized that acute high-altitude exposure would produce global hypomethylation, as well as increased methylation of the EGLN1 promoter region and decreased methylation of the EPAS1 promoter region, resulting in increased expression of HIF-2α and increased HIF-pathway activation. To test this hypothesis, 15 (5 women, 10 men) healthy participants of sea-level ancestry were recruited (age = 25 ± 4.8). DNA was isolated from venous blood samples which were collected during fasting at sea level and over the course of three days of acclimatization to 3800 m elevation at Barcroft Station (Bishop, CA). DNA methylation levels were measured at CpG sites across the genome using the Illumina Infinium MethylationEPIC chip, and local DNA methylation for EPAS1 and EGLN1 was obtained using a high-resolution melt technique. We identified several CpG sites throughout the genome that were differentially methylated during high-altitude exposure. The top gene ontology terms for differentially methylated sites include bone cell development, DNA damage repair pathways related to p53, and myeloid cell development. There were also significant decreases in CpG sites within HIF-pathway genes such as CD44 and FOXP1. Finally, DNA methylation levels within EPAS1 and EGLN1 changed significantly throughout the process of high-altitude acclimatization, with methylation levels increasing in some regions and decreasing in others. In conclusion, high-altitude exposure leads to complex changes in DNA methylation patterns throughout the genome. These changes likely play a key role in acclimatization and adaptation to chronic hypoxia and future studies will explore these mechanisms. This work has implications for understanding the role of epigenetics in diseases associated with hypoxia such as COPD, COVID-19, sleep apnea, and reproductive diseases such as preeclampsia and endometriosis.

This work was funded by a UCR Regent's Faculty Fellowship to ECH and by the UCR School of Medicine.

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.
Differential angiogenic response contributes to sexual dimorphism in right ventricular adaptation in male and female Fischer CDF rats subjected to pulmonary artery banding model
Authors: Chaudhary Ketul , Seelemann Erica , Panchakshari Sheethal , Wolverton Maxwell , Deng Yupu , Stewart Duncan
Published: May 2023

Background: Female sex has been associated with better right ventricular (RV) adaptation and survival in patients with elevated RV afterload; however, the mechanisms underlying these differences remain unclear. Therefore, we studied the mechanisms underlying sex differences in RV remodeling and development of RHF using the rat pulmonary artery banding (PAB) model. Methods: Adult male and female Fischer CDF rats were subjected to PAB or sham surgery and echocardiography was performed at 1- or 2-weeks post-PAB to evaluate RV structure and function. RV systolic pressure (RVSP) was measured using a pressure catheter and Fulton Index (RV/ left ventricle + septum) was measured to evaluate RV hypertrophy (RVH). To explore the mechanisms, a focused PCR array was performed to assess the expression of angiogenic genes in the RV of male and female rats subjected to sham or PAB procedure. RV endothelial cells (RVECs) were isolated from Fischer CDF rats and effects of female sex hormones on angiogenic ability of RVECs was assessed using Matrigel network formation assay. We also assessed the role of sphingosine kinase-1 (Sphk1) inhibitor, PF-543, in mediating the effects of female sex hormones on angiogenic potential of RVECs. Results: At 1- and 2-week post-PAB, RVSP and RVH were significantly elevated in PAB rats compared to control rats; however, no differences were observed between male and female rats. Cardiomyocyte surface area (330 vs 234 mm2, p<0.05) and fibrosis (6.96 vs 4.58%, p<0.05) were both significantly higher in male compared to female rats. RV end-diastolic diameter was also increased in male rats compared to female rats (3.33 vs 2.05 mm; p<0.05). On the contrary, RV function was preserved in female rats as indicated by higher cardiac index and fractional area change compared to male rats. Up-regulation of angiogenic genes, including Sphk1, was observed in the RV of female rats compared to male rats at 2 weeks post-PAB. Estradiol treatment increased network forming ability of RVEC isolated from Fischer CDF rats and this effect was inhibited by PF-543. Conclusions: Female Fischer CDF rats develop adaptive RV remodeling in response to PAB compared to mal-adaptive RV remodeling in male rats. Moreover, the better RV adaptation in female rats involves increased RV angiogenesis and these effect may be mediated through Sphk1.

Research Nova Scotia, Dalhousie 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.
TRPM7 contributes to TGF-ß signaling in renal fibroblast
Authors: Khan Abdul , Mankuzhy Pratheesh , Adebiyi Adebowale
Published: May 2023

Mammalian transient receptor potential melastatin (TRPM), the non-selective cation channel subfamily, has eight members and is extensively expressed in excitable and non-excitable cells where they perform diverse functions, including sensory transduction, magnesium reabsorption, cell adhesion, and vascular reactivity. TRPM channels have been detected in the kidney, and they participate in regulating osmotic and ion homeostasis. Members of the TRPM family contribute to ischemic kidney injury, but their function in renal fibroblast, a principal mediator of renal fibrosis associated with progressive kidney failure, is unclear. Hence, this study aimed to explore the expression and function of TRPM channels in primary mouse renal fibroblast. We demonstrated that among all TRPM channels, only TRPM 4, 6, and 7 are expressed in the cells. However, the expression of TRPM7 was at least 60% more than TRPM 4 and 6. TRPM7 is a bifunctional protein characterized by ion channel and kinase activity. Treatment of renal fibroblasts with transforming growth factor β(TGF-β) increased the expression of TRPM7. Considering the critical role of renal fibroblast in the development of renal fibrosis and TGF-βas a factor that drives fibrosis in chronic kidney disease, we examined the effect of siRNA-mediated knockdown of TRPM7 on pro-fibrogenic markers and mediators. We demonstrated elevated expression of fibrotic markers fibronectin, vimentin, and collagen type 1 in TGF-βtreated renal fibroblast, an effect attenuated by TRPM7 knockdown. The TGF-β-induced increase in fibrosis markers was accompanied by activation of SMAD3- and STAT3-mediated fibrotic signaling pathways with markedly elevated expression of phosphorylated SMAD3 and STAT3. Knockdown of TRPM7 attenuated expression of phosphorylated SMAD3 and STAT3 in TGF-β-treated renal fibroblast. Migration and proliferation of the cells were elevated when treated with TGF-β. Interestingly, the knockdown of TRPM7 diminished TGF-β-induced renal fibroblast migration and proliferation. Overall, this study suggests that TRPM7 is essential for the profibrotic signaling in renal fibroblast, which is associated with activating the canonical SMAD3 and non-canonical STAT3 pathways of fibrosis.

NIH: R01 HL151735-01

This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.
Acute Intermittent Hypoxia and Respiratory Strength Training to Improve Respiratory Function in Individuals with Chronic Spinal Cord Injury: Preliminary Outcomes
Authors: Vose Alicia , Welch Joseph , Nair Jayakrishnan , Michela Mir , Kathryn Cavka , Wauneka Clayton , Brunetti Gina , Snyder Hannah , Demark Lou , Mitchell Gordon , Fox Emily
Published: May 2023

Spinal cord injury (SCI) disrupts neural pathways to respiratory motor neurons, causing paralysis and breathing impairment, a major cause of illness and death in SCI. Acute intermittent hypoxia (AIH) is a promising therapeutic modality that elicits spinal synaptic plasticity, improving breathing in rodent models of SCI. AIH also elicits plasticity in limb motor systems in both rodent models and humans with chronic SCI, where functional gains are greatest when paired with task-specific training. The impact of similar combinatorial treatments on breathing ability is unknown. Here, we report preliminary breathing outcomes in seventeen adults with chronic SCI who received AIH and task-specific training (respiratory strength training; RST). Seventeen males with chronic SCI (33.7 ± 15 yrs of age; 1-28 yrs post-SCI; 12 cervical, 5 thoracic injuries; C1-T6 AIS A-D). Respiratory function was 52% ± 19% of the age-predicted normative function for expiratory pressure generation and 123% ± 32% of normative values for inspiratory function. Participants completed four random ordered 5-day protocols of AIH, Sham, RST, and AIH+RST, >3 weeks apart. AIH consisted of 15, 1-minute episodes of breathing a hypoxic gas mixture (9% oxygen), interspersed with 1.5-minute episodes of breathing room air (21% oxygen). Thirty minutes after AIH, RST involved both inspiratory and expiratory training; 4 sets of 6-12 breaths with the pressure threshold device set to 80% of each individual’s maximum. Sham treatments replicated AIH but used room air. A linear mixed model was used to test for differences in maximal inspiratory pressure (MIP), maximal expiratory pressure (MEP), and forced vital capacity (FVC) prior to and 1 day post-intervention. MIP increased 10±15.6% (pre 120±34cmH20, post 129±36 cmH20) 1 day after RST (p=0.001) and 6±10.5% (pre 123±34cmH20; post 131±34cmH20) 1 day after AIH+RST (p=0.04), but did not change after AIH or Sham. MIP increased by >10% in 5/17 participants following AIH+RST and 9/17 participants following RST. Neither MEP nor FVC changed following any block. Although there were no significant differences between AIH+RST and RST intervention blocks, there was a medium effect size (0.44). Since RST and AIH+RST preliminary outcomes suggest functional respiratory benefit, future steps will determine if the combinatorial treatment elicits greater gains. Examination of biomarkers associated with outcomes will provide insight into outcome variability.

Department of Defense CDMRP W81XWH1810718

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.
Putatively adaptive missense variant at Adrenergic Receptor Alpha-1A associated with decreased risk of Chronic Mountain Sickness in Andean highlanders
Authors: Gu Wanjun , Lawrence Elijah , Moya Esteban , Villafuerte Francisco , Simonson Tatum
Published: May 2023

Andean highlanders living at high altitude (>4200 m) for hundreds of generations exhibit distinct cardiovascular and ventilatory traits in response to environmental stress. Adrenergic Receptor Alpha-1A ( ADRA1A), a gene coding for the Alpha 1-A adrenergic receptor, has been previously shown to be under positive natural selection in the Andeans. ADRA1A has also been demonstrated to have a protective effect against cardiovascular complications in other lowland populations. We hypothesized that putatively adaptive single nucleotide variants (SNVs) of strong functional impact can be found in ADRA1A and associated with cardiovascular traits in the Andean highlanders.We examined data from the Composite of Multiple Signals test in 40 high-coverage whole genomes of Andean highlanders living in Cerro de Pasco, Peru (~4340 m), specifically focusing on SNVs with strong predicted functional impact. Genetic variants of interests were then genotyped and tested for phenotypic associations in an extended Andean cohort (132 males, 46 females). The presence of Chronic Mountain Sickness (CMS), a maladaptive syndrome observed in Andean highlanders characterized by excessive erythrocytosis, and resting heart rate during hypoxia were prioritized for the regression analysis. The genotype-phenotype association analysis adapted a multivariate linear model with sex as a stratum and age as a covariate.A missense variant (rs1048101, A>G) in the second exon of ADRA1A with strong predicted functional impact was tagged by the Composite of Multiple Signals analysis. In Andean males, the rs1048101 A allele was associated with 1.52-fold decreased risk for CMS (p<0.018) and attenuated resting heart rate at room air (~10% inspired O2 ) and at 21% inspired O2 (room air: p<0.019, 21% O2 : p<0.012). In women, the association between ADRA1A rs1048101 and CMS was not significant (p>0.917). In addition, women with more copies of the putatively adaptive A allele demonstrated increased heart rate both at room air and 21% inspired O2 (room air: p<0.033, 21% O2 : p<0.044) in contrast to observations in men.In conclusion, the putatively adaptive missense variant rs1048101 at ADRA1A demonstrated a protective effect against Chronic Mountain Sickness and was further associated with decreased resting heart rate in Andean males. The lack of replicability of these associations in females suggests potential sex-dependent effect of ADRA1A. Further experiments functionalizing the variant and validating the associations in large genome cohorts may shed light on the mechanisms of the gene.

This project is funded by R01HL145470.

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 A Metalloproteinase and Disintegrin 15 leads to exacerbated myocardial hypertrophy and dilation through activation of the calcineurin pathway in male but not female micev
Authors: Aujla Preetinder , Hu Mei , Kranrod Joshua , Viveiros Anissa , Kilic Tolga , Owen Caroline , Oudit Gavin , Seubert John , Kassiri Zamaneh
Published: May 2023

Cardiac dysfunction associated with cardiomyopathies is characterized by myocardial hypertrophy and dilation involving many cellular and molecular signalling events. A disintegrin and metalloproteinases (ADAMs) are membrane-bound proteinases with diverse functions, whose role in heart disease remains underexplored. ADAM15 is expressed in the heart and is downregulated in the failing human heart. In left ventricular (LV) specimens, ADAM15 levels did not change in patients with concentric hypertrophy (preserved ejection fraction) but was markedly decreased in hypertrophic and dilated failing cardiomyopathy. We investigated the role of ADAM15 in pressure overloaded cardiomyopathy in both male and female C57BL/6 mice. Loss of ADAM15 alone did not cause cardiomyopathy in both male and female mice up to 1 year of age. Male and female wildtype (WT) and ADAM15 knockout ( Adam15-/- ) mice were subjected to cardiac pressure overload by transverse aortic constriction (TAC) at 8 weeks of age. Adam15-/- female mice had comparable cardiac function and hypertrophy to their WT controls while, Adam15-/- male mice exhibited worsened decompensated hypertrophy and dilation with increased activation of mitogen activated protein kinases (pJNK, pERK1/2) compared to WT. Expression of integrin-α7 (but not integrin β1) increased significantly more in male Adam15-/- -TAC hearts, while the interaction of integrins with basement membrane (laminin) decreased consistent with increased LV dilation. Activity of calcineurin was higher in male Adam15-/- -TAC hearts along with greater de-phosphorylation of its target transcription factor, NFAT1. Calcineurin inhibition (cyclosporin A) blocked the excess hypertrophy and dilation in male Adam15-/- mice post-TAC. Calcineurin signalling has been shown to be inhibited by 17β-estradiol (E2), the circulating form of estrogen. Thus, the sex-dependent phenotypic differences in male and female Adam15-/- mice following pressure overload could be attributed to the inherent increased inhibition of calcineurin-mediated signalling due to the increased expression of estrogen in female mice.

Research supported by Canadian Institutes of Health Research (CIHR) grant

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.
Modulation of opioid overdose susceptibility due to context-dependent tolerance
Authors: Ayyalaraju Anika , Szujewski Caroline , Sullere Shivang , Garcia Alfredo
Published: May 2023

The US is in the midst of an opioid epidemic, which is primarily being driven by repeat opioid use (ROU). The primary cause of opioid overdose is opioid-induced respiratory depression (OIRD). It has been shown that the risk of overdosing, and subsequently death, can change depending on the environment in which the user takes the drug. This phenomenon is called context-dependent tolerance. However, how OIRD changes depending on the location of drug delivery is not known. The objective of this pilot study is to investigate context-dependent respiratory tolerance to OIRD and overdose. We repeatedly paired an injection of fentanyl (0.7 mg/kg/day i.p.) with a distinctive environmental context (fentanyl-paired (FP) environment) and saline with another distinctive context (saline-paired (SP) environment) in adult mice for five days while monitoring breathing via unrestrained whole-body plethysmography. The ROU protocol was followed by two test days where fentanyl was administered in both environments and breathing was measured. We found that minute ventilation was greater during OIRD in the FP environment as compared to the SP environment (n=4). In the second set of mice (n=6?), we tested overdose susceptibility following ROU by administering a high dose of fentanyl (5mg/kg) in both contexts. In contrast to the FP environment where no mice overdosed (n=0/6), n=4/6 mice overdosed in the SP environment. These data suggest a greater susceptibility to OIRD and overdose when in an environment not previously paired with fentanyl administration. This context-dependent effect on OIRD may be a significant psychophysiological factor driving opioid-related deaths in the ongoing opioid epidemic.

NIH: R01NS107421; R01HL163965; R01DA057767.

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.
Protective role of short chain fatty acids against Angiotensin II-induced mitochondrial dysfunction in brain endothelial cells: Potential role of Heme Oxygenase 2
Authors: Ait-Aissa Karima , Munkhsaikhan Undral , Abidi Ammaar H. , Kassan Adam , Kassan Modar
Published: May 2023

Objectives: Short chain fatty acids (SCFAs), the main metabolites released from the gut microbiota, are reduced during hypertension. SCFAs play a beneficial role on the cardiovascular system. However, the effect of SCFAs on cerebrovascular endothelial cells is yet to be uncovered. In this study, we used brain endothelial cells to investigate the in vitro effect of SCFAs on heme oxygenase 2 (HO-2) and mitochondrial function following Angiotensin-II treatment. Methods: Brain human microvascular endothelial cells were treated with Angiotensin II (Ang-II, 500nM for 24hours) in the presence and absence of SCFAs cocktail (1mM; acetate, propionate, and butyrate) and/or HO-2 inhibitor (SnPP 5 μM). At the end of the treatment, HO-2, endothelial markers (p-eNOS, NO production), inflammatory markers (TNFα, NFkB-p50 and -p65), calcium homeostasis, mitochondrial membrane potential, mitochondrial ROS and hydrogen peroxide (H2O2), and mitochondrial respiration were determined in all groups of treated cells. Results: Our data showed that SCFAs rescued HO-2 after Angiotensin II treatment. Additionally, SCFAs rescued Angiotensin II-induced eNOS reduction, mitochondrial membrane potential impairment and mitochondrial respiration damage. On the other hand, SCFAs reduced Angiotensin II-induced inflammation, calcium dysregulation, mitochondrial ROS, and H2O2. All these beneficial effects of SCFAs on endothelial cells and mitochondrial function occurred through HO-2. Conclusions: SCFAs treatment restored endothelial cells and mitochondrial function following Angiotensin II-induced oxidative stress. SCFAs exert these beneficial effects by acting on HO-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.
A trigger-substrate model of student engagement with learning
Authors: Witchel Harry
Published: May 2023

BACKGROUND: There is much controversy and disagreement about engagement with learning, in its definition, its causes and its effects. The recent APS book on “Technologies in Biomedical and Life Sciences Education” outlines these controversies. AIM: To develop upon previously proposed engagement models by using trigger and substrate interactions between contributory factors in order to explain how causative factors may have minimal or no effects on learning when required coincident factors are absent. METHOD: Trigger-substrate steps include a longer-lasting, undergirding substrate factor as well as a short-lived trigger factor, which together act as the cause for the outcome. RESULTS: The model that we propose has engagement, effort and use of resources resulting from the triggers of teaching and providing resources, with a substrate of internalized motivation and a sense of belonging. Continuing forward, engagement, effort and use of resources is a trigger for learning and other benefits, and these results require a substrate of strategies and preparedness in the student. Learning can lead to both positive and negative feedback effects via assessment, feedback (from instructors and the institution), and emotions, which can act via metacognition, incentives and social reinforcement, and achievement, identification (of the student with the learning and outcomes), and the educational climate. CONCLUSIONS: Trigger-substrate causality may help to clarify the inconsistencies seen in education results between traditional theories based on teaching and more recent theories that have focused on the learner.

The research has been funded by Brighton and Sussex Medical School

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.
Bitter melon extract affects cell-extracellular matrix interaction in human metastatic breast cancer cells
Authors: Bhetwal Bhupal , Bittar Elias , Throop Chase , Remedi Marissa , Kopecek Kalie
Published: May 2023

Introduction: Bitter melon extract (BME) is known to exhibit cytotoxic effects on breast cancer cells (MCF-7). However, the molecular mechanisms by which BME exerts cytotoxic effects are not established. Integrins (which are transmembrane cell surface proteins) are universally expressed in all cell types and play critical roles in anchoring cells to the extracellular matrix and hence their survival. Integrin proteins when activated in turn activates a cascade of intracellular signaling steps (such as activation of focal adhesion kinase, FAK) which facilitates cell attachment, migration, survival, division etc. Aims: We aimed to investigate if BME exerts cytotoxic effects on MCF-7 cells via inhibiting attachment of cells to the extracellular matrix. We hypothesized that BME decreases expression of integrins and hence activation of FAK leading to cell cytoxicity. Methods: Fresh bitter melons were purchased from an Asian grocery store and the extract (BME) was extracted, centrifuged, and filter sterilized. The MCF-7 cells were cultured in DMEM medium with 1% BME (v/v). After culturing cells for 48 hours, pictures of cultures were taken to confirm cytotoxic effects on cells. In our earlier experiments, BME induced decrease in cell viability was also confirmed using Trypan blue exclusion and MTT assays. The cells were harvested and changes in the protein expression of β1-integrin and phospho-FAK (activated FAK) were determined using anti-β1-integrin and anti-phospho-FAK antibodies in the western blotting. Results & Discussion: BME exerted cytotoxic effects on MCF-cells (N=4). BME also reduced expression level of β1-integrin protein by more than 50% (N=3 with duplicate gels). Also, BME reduced expression of phospho-Tyr 397-FAK to below 20% (N=3), and total FAK to below 40% (N=3). The loading control protein GAPDH was not affected by the BME treatment (N=3). The data together supports our hypothesis. In the future, we will be running more sets of experiments to confirm our findings.

FRD-MUCOM. All authors contributed equally to this work.

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.
SKQ1 Improves Trimethylamine-N-Oxide-Induced Endothelial Dysfunction by Attenuating Oxidative Stress and Restoring Junctional Proteins
Authors: Koka Saisudha , Powers Zachary , Boini Krishna
Published: May 2023

In recent years, the role of microbiota and microbial metabolites in the progress of aging and age-related diseases has been attracting increased attention. In this context, trimethylamine N-oxide (TMAO) is a pro-atherogenic and pro-inflammatory metabolite derived from the gut microbial metabolism of trimethylamine and is found to be elevated in patients with age-related cardiovascular disorders. We identified that TMAO treatment in mice has enhanced mitochondrial ROS production, endoplasmic reticulum stress and caused significant endothelial dysfunction. The present study investigated whether mitochondria-targeted antioxidant SKQ1 protected against TMAO-induced endothelial dysfunction. Endothelial cells were treated with or without TMAO (30μM) in the cell culture media. TMAO treated cells showed significant increase in both total ROS as well as mito-ROS production compared to untreated control group (n=8/group; p<0.05). In addition, western blot analysis demonstrated that TMAO treatment significantly decreased tight junction proteins such as occludin, ZO-1 and VE-Cadherin which were restored upon SKQ1 treatment (150nM, 12h). TMAO (30μM) treatment for 24 h induced significant mitochondrial dysfunction as evidenced by decreased mitochondrial membrane potential, increased mitochondrial ROS levels, and enhanced endothelial cell permeability compared to the control group (n=8/group; p<0.05). Treatment with a SKQ1 (150nM, 12h) significantly inhibited TMAO-induced ROS production and protected against increased endothelial cell permeability and mitochondrial ROS production (n=8/group; p<0.05). In conclusion, mitochondria-targeted antioxidant SKQ1 protects against TMAO induced endothelial dysfunction by attenuating ROS production and disruption of tight junction proteins.

This work is supported by NIH R01 HL148711 award to Saisudha Koka

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.
17 Beta-estradiol impedes aortic root dilation and rupture in male Marfan mice
Authors: Saddic Louis , Escopete Sean , Zilberberg Lior , Kalsow Shannon , Egbhali Mansoureh , Parker Sarah
Published: May 2023

Background: Marfan syndrome causes a hereditary form of TAA with dilation of the aortic root. Male patients with Marfan syndrome are more likely than women to have aortic dilation and dissection and mouse models of Marfan syndrome demonstrate larger aortic roots in males compared to females even after adjustment for body size. In this study we examine the effects of estrogen17 β-estradiol on aortic dilation and rupture in a Marfan mouse model. Methods: Marfan male mice were administered estrogen17 β-estradiol pellets with 60 day release and the growth in aortic root size was measured every 2 weeks for 8 weeks. Aortic root tissue from vehicle and 17 b-estradiol mice were subjected to proteomic analysis and bioinformatics was used to ascertain enriched pathways. Marfan mice with and without 17 b-estradiol were also treated with continuous angiotensin II infusion and survival was determined for 30 days. Results: Male Marfan mice with estrogen17 β-estradiol had a significant reduction in the ratio of aortic diameter 8 weeks after pellet implantation to baseline aortic diameter compared to the same ratio in Marfan mice with sham surgery. Proteomic analysis demonstrated complement C3 and C4 protein upregulation in Marfan mice compared to wild type and Marfan mice treated with 17 b-estradiol. Aortic smooth muscle cells express complement components in vivo and in vitro and expression of these factors are regulated by cytokines and estrogen17 β-estradiol in vitro. Additionally, 17 b-estradiol and female sex protect against aortic rupture when Marfan mice are treated with continuous infusion of angiotensin II and this protection correlates with lower protein levels of C3. Conclusions: Our findings support a protective role of 17 b-estradiol in preventing the dilation and rupture of aortic roots in Marfan male mice and suggest that these therapeutic actions may develop through anti-inflammatory properties.

FAER Foundation for Anesthesia Education and Research

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.
Impaired endothelial function via fatty acids and the potential role of oxidative stress
Authors: Kovarik Jack , Holwerda Seth
Published: May 2023

Purpose: Excess plasma lipids promote oxidative stress and impaired vascular function. Therefore, we tested the hypothesis that a water-soluble antioxidant (ascorbic acid, AA) would attenuate reductions in endothelium-dependent dilation resulting from acutely elevated plasma fatty acids. Methods: A 20% IV fat emulsion (Intralipid) was administered for 2 hours to 8 healthy, middle-aged adults (2 men/6 women) with and without co-infusion of ascorbic acid (separate visits) in a double-blinded, crossover study design. Co-infusion of AA was administered at 0.06g/kg fat free mass in 100 ml saline at 5 mL/min over 20 min (bolus) followed by a drip infusion at 0.02 g/kg fat-free mass in 30 ml saline at 0.33 mL/min over 90 min. Endothelium-dependent dilation was assessed via brachial artery flow-mediated dilation (FMD) and expressed as % increase in diameter from baseline before forearm occlusion. Results: Lipid infusion significantly increase plasma fatty acid concentrations (w/o AA: +36 ± 18 vs. with AA: +41 ± 13 vs. μmol/L, P=0.84). AA infusion significantly increased plasma ascorbic acid concentrations (w/o AA: -1 ± 7 vs. with AA: +26 ± 11 μmol/L, P=0.04). Compared with baseline, FMD was significantly reduced following lipid infusion at (Baseline: 9.3 ± 1.1 vs. 20 min: 4.4 ± 1.3 vs. End: 5.3 ± 2.9 %, P=0.03), and when statistically adjusting for the stimulus (shear rate area under the curve) via analysis of covariance (P=0.02). FMD was also significantly reduced following lipid infusion with co-infusion of AA (Baseline: 8.9 ± 1.0 vs. 20 min: 5.3 ± 1.0 vs. End: 6.4 ± 3.8 %, P=0.02), but not when statistically adjusting for shear rate under the curve (P=0.08). Conclusions: Elevated plasma fatty acids impair endothelium-dependent dilation in healthy adults. However, co-administration of an antioxidant (ascorbic acid) limited the reduction in FMD when correcting for shear rate. Therefore, these preliminary data suggest that fatty acids may reduce endothelium-dependent dilation via an oxidative stress mechanism.

Funding and support: R01HL159370-01 (S.W.H.). This work was also supported by a CTSA grant from NCATS awarded to the University of Kansas for Frontiers: University of Kansas Clinical and Translational Science Institute (# UL1TR002366). The contents are solely the responsibility of the authors and do not necessarily represent the official views of the NIH or CTSA.

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 novel Bexarotene analogs for treating cutaneous T-cell lymphomas
Authors: Warda Ankedo , Staniszewski Lech , Sabir Zhela , Livingston Sarah , Sausedo Michael , Reshi Sabeeha , Ron Eyal , Marshall Pamela , Wagner Carl , Jurutka Peter
Published: May 2023

Bexarotene, a drug approved for the treatment of cutaneous T-cell lymphoma (CTCL), is classified as a rexinoid due to its ability to act as a retinoid X receptor (RXR) agonist with high specificity. Rexinoids are capable of inducing RXR homodimerization leading to the induction of apoptosis and inhibition of proliferation in human cancers. Numerous studies have shown that bexarotene is effective in reducing viability and proliferation in CTCL cell lines. However, many treated patients present with cutaneous toxicity, hypothyroidism, and hyperlipidemia due to crossover activity with retinoic acid receptor (RAR), thyroid hormone receptor (TR), and liver X receptor (LXR) signaling, respectively. In this study, fourteen novel analogs were evaluated for their potential to bind RXR through modeling and then assayed in an RXR-RXR mammalian-2-hybrid (M2H) system and in RXRE-mediated luciferase reporter assays. In addition, these analogs were tested for their effectiveness to inhibit proliferation in CTCL cells relative to bexarotene. Furthermore, the most effective analogs were analyzed via qPCR to determine efficacy in modulating expression of two critical tumor suppressor genes, ATF3 and EGR3. Our results suggest that these new compounds possess similar or enhanced therapeutic potential as several of our novel rexinoids display more selective RXR activation with equivalent or greater reduction in CTCL cell proliferation, as well as the ability to induce ATF3 and EGR3. This work broadens our understanding of RXR-ligand relationships and permits development of more highly efficacious pharmaceutical drugs. Modifications of RXR agonists can yield agents with enhanced biological selectivity and potency when compared to the parent compound, potentially leading to improved patient outcomes.

NCUIRE Undergraduate Research Program (ASU) & National Institutes of Health (NIH) CA140285 (to PWJ, CEW and PAM)

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.
Vav1-HIF1α-Glut1, a novel axis to initiate neurodegenerative disorders
Authors: Hong Jaewoo
Published: May 2023

Vav1 is a Rho/Rac (Ras-related C3 botulinum toxin substrate) guanine nucleotide exchange factor (GEF) expressed in immune cells and endothelial cells involved in a wide range of cellular functions, including protumorigenesis and inflammation. Vav1 is unstabilized in normoxic conditions and stable in hypoxic conditions. When Vav1 is stable, Vav1 increases the accumulation of the transcription factor HIF (Hypoxia Inducible Factor)-1α, which activates the transcription of target genes on HIF-related element (HRE) to initiate a cellular response to low oxygen. One of the genes induced by HIF-1α is GLUT (Glucose Transporter)-1, the major glucose transporter expressed in vessels that supply glucose, the brain's energy source. Here, we identify a role for Vav1 in providing glucose to the brain to suppress neurodegeneration. We observed that Vav1 deficiency suppresses HIF-1α and GLUT-1 levels in endothelial cells, including blood-brain barrier cells. The decrease of GLUT-1, in turn, reduces glucose uptake to endothelial cells both in vitro and in vivo and reduces glucose transportation to neurons and astrocytes.Furthermore, endothelial cell-specific Vav1 conditional knock-out mice show glucose uptake deficiency as well as impaired brain coordination. Our findings suggest that Vav1 promotes learning and memory by activating HIF-1α and GLUT-1, thereby transporting glucose to the brain. We further demonstrate the importance of glucose transport by endothelial cells in brain functioning and reveal a potential new axis for targeting GLUT-1 deficiency syndromes and other neurodegenerative disorders.

This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF), funded by the Ministry of Education (No. 2021R1I1A3043909).

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.