bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of MYOCYTER and MUSCLEMOTION in the analysis of Induced Pluripotent Stem Cell Derived Cardiomyocyte Contractility
Authors: Anfinson Melissa , Liang Huan-Ling , Kodgi Suraksha , Atkinson Grant , Li Irene , Mitchell Yukiko , Holland Hayden
Published: May 2024

Patient-specific induced pluripotent stem cells (iPSCs) differentiated into cardiomyocytes (CMs) offer tremendous opportunities for cardiac disease modeling and advancements in precision medicine. There is a need for technologies that allow noninvasive and precise measurements of CM function, such as contractility, to increase throughput for drug screening and testing efforts. Hypoplastic Left Heart Syndrome (HLHS) is a rare and complex congenital heart defect characterized by hypoplasia of the left ventricle, proximal aorta, as well as stenosis or atresia of the mitral and/or aortic valves. Previously it was demonstrated that iPSC-CMs from an HLHS patient with a genetic variant in the alpha myosin heavy chain ( MYH6 gene) exhibited an impaired cardiomyocyte phenotype (dysmorphic sarcomere structure, compensatory expression of MYH7, and altered contractility). Gene editing using CRISPR/Cas9 rescued the phenotype, demonstrating the utility of MYH6 iPSC-CMs as a useful disease model for HLHS. Critical parameters of CM function include contraction and relaxation, assessing systolic and diastolic dysfunction, respectively, in iPSC-CMs. The aim of this study is to compare features from two open-source macros for ImageJ: MYOCYTER and MUSCLEMOTION. MYOCYTER improves upon previous plugins available by allowing for users to select parameters. Both methods allow measurement of movement from high-speed movies. MYOCYTER enables the user to select an optimal threshold, size, and cell count to minimize disturbances such as cellular fragments, background noise, and floating bubbles, to maximize precision during analysis. MUSCLEMOTION allows rapid and easy measurement of movement from high- speed videos and can measure and compare relative or absolute parameters. This study will determine whether a systolic or diastolic dysfunction phenotype is observed under different magnification settings and evaluate the effect of dosing with pharmaceutical compounds. Finally, benefits and drawbacks of both macros will be investigated.

Children's Research Institute.

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.
Programming of neutrophil transcriptome by endothelial ERG maintains anti-inflammatory vascular niche in the lungs
Authors: Vellingiri Vigneshwaran , BR Vijay Avin , Joshi Jagdish Chandra , Akhter Zahid , Anwar Mumtaz , Banerjee Somenath , Pinho Sandra
Published: May 2024

Neutrophils, the predominant blood leukocyte and first responders to the infection, reside as the marginated pool in the lungs. Vascular hyperpermeability and activation of infiltrating neutrophils is the hallmark of lethal acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). However, signaling nodes that govern crosstalk among these ontologically distinct cell types to maintain tissue homeostasis remain unclear. Here, we identify the ERG transcription factor, which maintains endothelial cell (EC) lineage, as the instructor of anti-inflammatory neutrophils. We show that ERG is highly expressed in lung EC, but the expression was reduced markedly during neutrophilic injury by bacterial pneumonia. Intravital imaging and FACS analysis of mice lungs conditionally lacking ERG in the endothelium (iEC-ERG−/−mice) showed increased neutrophil retention and activation due to rewiring of their transcriptome (hereafter referred to as EC-ERG null neutrophils). RNA sequencing of EC-ERG null neutrophils showed genes enriched with inflammation (IL-1β, TNF-α, MIP-2α), survival (RelB, CD47), and retention (CXCR4) markers. Neutrophils isolated from the blood of ARDS patients similarly showed increased expression of IL-8, TNF-α, and CXCR4 expression. EC-ERG null neutrophils induced lung injury when adoptively transferred into a naïve mouse. EC-ERG loss elicited an immune migratory and chemotactic program by activating the NF-κB-IL8 cascade, exacerbating ALI in a mouse model. We show that ERG in endothelium preserves neutrophil activation and infiltration by upregulating the multipurpose deubiquitinase A20 expression in mouse and human lung endothelial cells (EC). Rescuing A20 deubiquitinase or suppressing IL8-CXCR2 axis through small molecule inhibitor, Reparixin, reversed hyperpermeability, and neutrophilic injury. In summary, our study identifies specialized ERG-instructed anti-inflammatory ‘immune niche’ to prevent neutrophilic inflammation and lung injury.

National Institutes of Health (NIH) Grants HL060678, HL084153.

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.
Cortical Sources And Autonomic Nervous System Response Of Listening To North Indian Classical Music
Authors: Sahoo Abhisek , Tayade Prashant , Muthukrishnan Suriyaprakash , Kaur Simran , Sharma Ratna , Nayyar Madhavi
Published: May 2024

BACKGROUND: Music can affect the human brain and qEEG with its sub-second resolution can be used to study brain activity. The North Indian classical music’s (NICM) effect on brain activity is largely undiscovered. OBJECTIVE: To find out the cortical sources activated along with the autonomic nervous system response while listening to NICM. Methods: 30 Indian subjects (Mean age- 26.1 and (SD) - 1.4 years) were asked to listen to 4 NICM ragas of 5 minutes each with increasing minor note to major note ratio i.e., M1(0), M2(0.16), M3(0.4), M4(1.33).128 channel of EEG signal was recorded which was preprocessed and cortical source localization was done using sLORETA.The autonomic nervous system response while listening to each music excerpt was assessed using Heart Rate Variability parameters by measuring lead II electrocardiography. RESULTS: The cortical sources analysis showed increased activation in cortical regions associated with the extraction of acoustic features of music (superior, middle, and inferior temporal gyruses in addition to fusiform and supramarginal gyrus), emotion generation (precuneus and inferior frontal gyri) and Default Mode Network (posterior cingulate cortex, medial prefrontal cortex, and inferior parietal lobule) while listening to M1. There was a decreased activation in these areas while listening to M2, M3 & M4 (as the minor notes increased).The mean heart rate was significantly higher while listening to M4. There was a reduction in HF while listening to M4 and M3.There was a significant decrease in RMSSD while listening to M4 as compared to the resting state. CONCLUSION: Music can affect brain activity and autonomic function. Music with major notes causes activation of DMN areas causing mind wandering and self-referential mental activity than music with minor notes which decreases DMN activity.In terms of autonomic function increase in minor notes caused decrease in RMSSD and HF signifying an increase in stress and reduced parasympathetic tone.

The authors declare no competing interest. The study was approved by the Institutional Review Board (IRB). No Grant was used.

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.
Renal Intercalated cells: allien cells inside us?
Authors: Graciano Miguel
Published: May 2024

Mammalian renal intercalated cells (ICs) are known for their role in acid secretion and acid- base regulation. Based on previously published data, we discussed the theoretical reasons behind the development of additional renal IC biology characteristics, tracing them back phylogenetically to the simplest animals and protozoa. ICs have the following additional functions or attributes: (1) they play immunological roles in protecting the kidneys against both infective and aseptic kidney damage; (2) they are energized by V-ATPases in a similar fashion to protozoa; (3) they possess a T-antigen that is common in embryonic and cancer cells, which confers invasiveness ability to those cells; and (4) they exhibit plasticity and the ability to regenerate other epithelial cells (i.e., they exhibit stem cell behavior). Renal ICs may derive from amoeboid cells sharing these characteristics that originated from an evolutionary line that includes protists, or even the Last Eukaryotic Common Ancestor (LECA).

None.

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.
Lysophosphatidic Acid Receptor 3 Activation Is Involved in the Regulation of Erythrocyte Differentiation Through Ferroptosis
Authors: Huang Yi-Xun , Lee Hsinyu
Published: May 2024

Ferroptosis, a unique form of programmed cell death trigged by lipid peroxidation and iron accumulation, has been implicated in embryonic erythropoiesis and aging. Our previous research demonstrated that lysophosphatidic acid receptor 3 (LPA3) activation mitigated oxidative stress in progeria cells and accelerate the recovery of acute-anemia in mice. Given that both processes involve iron metabolism, we hypothesized that LPA3 activation might mediate cellular ferroptosis. In this study, we used LPA3 agonists 1‐Oleoyl‐2‐O‐methyl‐rac‐glycerophosphothionate (OMPT) to activate LPA3 and examine its effects on the ferroptosis process. OMPT treatment elevated anti-ferroptosis genes protein expression, including solute carrier family 7 member 11 (SLC7A11), glutathione peroxidase 4 (GPX4), heme oxygenase-1 (HO-1), and ferritin heavy chain (FTH1) in erastin-induced cells. Furthermore, OMPT reduced lipid peroxidation and intracellular ferrous iron accumulation, as evidenced by C11 BODIPYTM 581/591 Lipid Peroxidation Sensor and FerroOrange staining. These observations were validated by applying LPAR3 siRNA in the experiments mentioned above. In addition, the protein expression level of nuclear factor erythroid 2-related factor (NRF2), a key regulator of oxidative stress regulator, was also enhanced in OMPT treated cells. Lastly, we verified that LPA3 plays a critical role in erastin-induced ferroptotic human 25 erythroleukemia K562 cells. OMPT rescued the erythropoiesis defect caused by erastin in K562 cells through using Gly A promoter luciferase assay. Taken together, our findings suggest that LPA3 activation inhibits cell ferroptosis by suppressing lipid oxidation and iron accumulation, indicating that ferroptosis could potentially serve as a link between LPA3, aging and erythropoiesis.

MOST 110-2311-B-002-026 MOST 111-2311-B-002-007.

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.
Lifespan Effects of Muscle-specific Androgen Receptor Overexpression on Body Composition of Male and Female Rats
Authors: Barsky Sabrina Tzivia , Monks Douglas Ashley
Published: May 2024

Androgenic actions of gonadal testosterone are thought to be a major mechanism promoting sex differences in body composition across the lifespan. However, this inference is based largely on studies of androgen receptor (AR) function in late adolescent or emerging adult rodents. Here we assess body composition and quantify AR expression in skeletal muscle of rats at defined ages, comparing wild-type (WT) to transgenic HSAAR rats which overexpress AR in skeletal muscle. Male and female HSAAR and WT Sprague Dawley rats (N=288) underwent DEXA scanning and tissue collection at post-natal day (PND) 1, 10, 21, 42, 70, 183, 243, and 365. As expected, sex differences in body composition and muscle mass largely onset with puberty (PND-21), with no associated changes to skeletal muscle AR protein. In adulthood, HSAAR increased tibialis anterior (TA) and EDL mass in males, and reduced the expected gain in gonadal fat mass in both sexes. In WT rats, AR protein was reduced in soleus, but not TA, throughout life. Nonetheless, soleus AR protein expression was greater in males than females at all ages of sexual development, yet only at PND-70 in TA. Overall, despite muscle AR overexpression effects, results are inconsistent with major sex differences in body composition during sexual development being driven by changes in muscle AR, but rather suggest that changes in ligand promote sexual differentiation of body composition during pubertal timing. Nonetheless, increased skeletal muscle AR in adulthood can be suffcient to increase muscle mass in males, and reduce adipose in both sexes.

This work was supported by an NSERC Grant awarded to D.A.M. (RGPIN 312458).

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.
Allometric scaling of the parameters characterizing venous return surface in the generalized framework of circulatory equilibrium
Authors: Sato Kei , Peterson Jon , Uemura Kazunori , Nishikawa Takuya , Yokota Shohei , Matsushita Hiroki , Morita Hidetaka
Published: May 2024

Study objective: In the generalized framework of circulatory equilibrium (GCE), the integrated cardiac output (CO) curve characterizes the pumping abilities of the left and right hearts, whereas the venous return (VR) surface characterizes the preloading properties of the systemic and pulmonary circuits. Equilibrium CO (= VR), left (PLA) and right (PRA) atrial pressures are predicted from the intersection between the CO curve and VR surface. In VR surface, VR is theoretically related with stressed blood volume (V), PLA and PRA as: VR =V/W − Gs × PRA − Gp × PLA, where Gs and Gp is a ratio of systemic (Cs) and pulmonary (Cp) vascular compliance to W (time constant of the systemic and pulmonary circuits), respectively. However, there was a concern whether the standard parameters can be applicable to animals with different body size including human. The objective of this study is to experimentally investigate whether an allometric scaling of the parameters (Gs, Gp, W, Cs, Cp) of the VR surface is feasible. Hypothesis: Kleiber’s law indicates that an animal's metabolic rate scales to the 3⁄4 power of the animal's body weight (BW). Based on this, we hypothesize that Cs and Cp may be proportionate to BW, W may be proportionate to BW1/4. Hence, Gs and Gp may be proportionate to BW3/4. Methodology: Seven mongrel dogs (BW 26±2.8 kg) and 4 beagles (BW 9±0.5 kg) were anesthetized, and their left and right hearts were replaced by dual mechanical pumps. While V was kept constant, by controlling the speed of the fluid pumps, VR (ml/min), PLA and PRA (mmHg) were changed variably over a wide range to obtain six sets of VR, PLA and PRA. After the change of a known amount of V (4 mL/kg), six sets of VR, PLA and PRA were obtained in a similar manner. Using 12 sets of VR, PLA and PRA, we obtained Gs, Gp, W, Cs, and Cp using regression analysis in each animal. Finally, we analyzed relations between BW and all these parameters using regression analysis over the 11 animals. Data: Gs (r2=0.73, p value for independent variable piv<0.01; p value for intercept, pi=0.57) and Gp (r2=0.81, piv<0.01, pi=0.64) were proportionate to BW3/4. Cs (r2=0.37, piv=0.027, pi=0.40) and Cp (r2=0.61, piv<0.01, pi=0.48) were proportionate to BW. However, W (r2=-0.11, piv=0.90, pi=0.17) was not associated with BW1/4. Summary of results: All parameters characterizing VR surface except for W were significantly associated with BW. W did not show a significant association with BW, potentially due to the low variations of BW. Conclusions: Allometric scaling of VR surface may be feasible and effective in future clinical application of GCE.

NTT Research, Inc.

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.
Enhanced DNA Damage Response in a Clade of Long-Lived Bats Resolved Using Chromosome-Length Genome Assemblies
Authors: Vazquez Juan , Lauterbur M Elise , Capel Samantha , Enard David , Buchalski Michael , Sudmant Peter
Published: May 2024

Lifespan is one of the most variable traits across the entire tree of life, and especially in mammals. Differences in lifespans between closely-related species provides a promising avenue for discovering novel pro-longevity pathways using evolutionary techniques. Previous studies focused on the evolution of longevity-associated traits, such as DNA damage response, have been hampered by a combination of low-quality genomes, low-phylogenetic coverage, or long evolutionary times, all of which can negatively affect their power to detect genes associated with longevity. In order to comprehensively study the evolution of aging and aging-associated traits in bats, we generated chromosome-level reference genomes and primary cell line libraries from a 10-million-year-old clade of 9 California Myotis species spanning a 3-fold range of lifespans. Increases and decreases in longevity independent of body size have evolved multiple times in this clade, providing a dynamic range which can be studied through functional genomics. Leveraging both genomes and cell lines, we identify several pathways specifically associated with longevity, in addition to other longevity-associated traits such as DNA repair and immunity; and show that these changes are associated with cellular resistance to various forms of chemically-induced DNA damage. These pathways represent new targets for exploration using primary cell cultures, and contribute to our understanding of how both agonistic and antagonistic pleiotropy play a role in the evolution of longevity.

NSF PRFB 2109915 NIH 5R35GM142916-03.

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.
Effect of Breathing Room Air Through a Two-Way Non-Rebreathing Valve on HRV in BI and NBI College-Aged Students
Authors: Poff Hannah , Talens Kate , Ehlert Luke , Wiseman Connor , Martino Paul , Miller Daniel P. , Miller Justin
Published: May 2024

Behavioral inhibition (BI) is a temperament associated with increased vulnerability to stress compared to non-behaviorally inhibited (NBI) individuals. Heart-rate variability (HRV) analysis to assess physiological stress has been growing in popularity due to its association with crucial physiological functions, including cardiac activity, autonomic nervous system activity, and physiologic stress. Previous studies in our lab have demonstrated that HRV in female college-age students expressing a BI temperament is significantly lower than in NBI individuals while breathing room air through a two-way non-rebreathing valve. These findings suggested that the parasympathetic nervous system is partially inhibited at rest in BI females; however, it is unknown if the parasympathetic nervous system in these individuals is inhibited prior to or after breathing through a breathing valve. Our current study will address this question by measuring HRV in BI and NBI individuals while breathing room air for 15 minutes without a breathing valve and for 10 minutes with a two-way breathing valve. Raw electrocardiogram signals will be collected throughout the study protocol and will be used to calculate HRV, which will be measured using a BIOPAC data acquisition system during the experiment. BI individuals will be identified through a series of self-reported questionnaires. Our preliminary results indicate that BI individuals have a lower HRV and are stressed throughout the duration of the study.

Thank you to Carthage College's Biology and Neuroscience Department for allowing this research project to be conducted.

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.
Phenotypic Sexual Dimorphism in Response to High Fat Diet in C57BL/6J Mice Lacking Liver Androgen Receptor
Authors: Rahman Md , Andrisse Stanley
Published: May 2024

Previous research has indicated that liver androgen receptors may play a role in modulating disease. This study aims to investigate the pathophysiology of high fat diet (HFD) induced dysglycemia in male and female liver androgen receptor knockout (LivARKO) mice. We performed metabolic tests on LivARKO female and male mice fed a high fat diet (HFD) or a control diet (CD) (from Research Diets Inc) during months 1 or 2 after starting the diet. Additionally, we performed western blot and qRT-PCR analysis on the livers of the mice to examine intermediates in the insulin signaling pathway. LivARKO-HFD female mice displayed no difference in glucose tolerance compared to female LivARKO-Control mice. Whereas in WT female mice, HFD impaired glucose tolerance (IGT). Our data suggests that starting at one-month LivARKO may be protecting female mice from HFD-induced metabolic dysfunction. LivARKO-HFD female mice displayed significantly worse insulin sensitivity at 15 minutes compared to LivARKO-Control (Con) female mice; but, strangely, LivARKO-HFD female mice had significantly better insulin sensitivity at 60 and 90 minutes compared to LivARKO-Con female mice. Despite protecting against IGT, LivARKO did not protect against HFD-induced hyperinsulinemia (HI) in female mice. In contrast to females, male LivARKO-HFD mice displayed impaired glucose tolerance (IGT) compared to male LivARKO-Con mice. Thus, LivARKO is not protective against HFD-induced glucose metabolic dysfunction in male mice. Lastly, LivARKO-HFD female mice maintained hepatic insulin sensitivity whereas LivARKO-HFD male mice displayed hepatic insulin resistance. These findings suggest that LivARKO delayed the onset of HFD-Induced dysglycemia in female mice.

Funding: S.A. grant support from the National Science Foundation (NSF) Inclusion across the Nation of Communities of Learners of Underrepresented Discoverers in Engineering and Science (INCLUDES, HRD-1931045). S.A. grant from the National Institutes of Health (NIH) 1R01DK126892-01A1.

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.
LOXL2 inhibition ameliorates pulmonary artery remodeling in pulmonary hypertension
Authors: Steppan Jochen , wang Huilei , Nandakumar Kavitha , Poe Alan , Pak Lydia , Brady Travis , Gadkari Mahin
Published: May 2024

Background: Conduit pulmonary arterial stiffening and the resultant increase in pulmonary vascular impedance has emerged as an important underlying driver of pulmonary arterial hypertension (PAH). Given that matrix deposition is central to vascular remodeling, we evaluated the role of the collagen crosslinking enzyme lysyl oxidase like 2 (LOXL2) in this study. Methods and Results: Human pulmonary artery smooth muscle cells (PASMCs) subjected to hypoxia showed increased LOXL2 secretion. LOXL2 activity and expression were markedly higher in primary PASMCs isolated from pulmonary arteries of the rat Sugen 5416 + hypoxia (SuHx) model of severe PH. Similarly, LOXL2 protein and mRNA levels were increased in pulmonary arteries (PA) and lungs of rats with PH (SuHx and monocrotaline (MCT) models). Pulmonary arteries (PAs) isolated from rats with PH exhibited hypercontractility to phenylephrine and attenuated vasorelaxation elicited by acetylcholine, indicating severe endothelial dysfunction. Tensile testing revealed a a significant increase in PA stiffness in PH. Treatment with PAT-1251, a novel small-molecule LOXL2 inhibitor, improved active and passive properties of the PA ex vivo. There was an improvement in right heart function as measured by right ventricular pressure volume loops in-vivo with PAT-1251. Importantly PAT-1251 treatment ameliorated PH, resulting in improved pulmonary artery pressures, right ventricular remodeling, and survival. Conclusion: Hypoxia induced LOXL2 activation is a causal mechanism in pulmonary artery stiffening in PH, as well as pulmonary artery mechanical and functional decline. LOXL2 inhibition with PAT-1251 is a promising approach to improve pulmonary artery pressures, right ventricular elastance, cardiac relaxation, and survival in PAH.

This work was supported by a NHLBI grant R01HL105296 (to D.E.B.), a NHLBI grant R01HL148112 01 (to L.S.), two Stimulating and Advancing ACCM Research (StAAR) grants from the Department of Anesthesiology and Critical Care Medicine, JHU (to L.S. and J.S.), NHLBI grants R01HL073859 and R01HL126514 (to L.A.S) and a NHLBI K08 grant K08HL145132 (to J.S.).

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.
Physiopathological Mechanisms of Type 1 Cardiorenal Syndrome Induced by Acute Myocardial Infarction
Authors: Cavalheiro Rollssman , Brognara Fernanda , Aguiar da Silva Carlos Alberto , Castania Jaci , Salgado Helio
Published: May 2024

Objectives: Cardiovascular diseases are the leading global cause of mortality. Approximately 20 to 31% of acute myocardial infarction (AMI) cases progress to renal dysfunction, indicating concurrent cardiac and renal alterations, characterizing Cardiorenal Syndrome Type 1 (CS1). Therefore, this study evaluates the CS1 onset and progression three days after AMI by examining renal and cardiac function and their inflammatory responses. The study hypothesizes that inflammatory mediators are a key component contributing significantly to the onset and progression of CS1 pathophysiology. Methods: Male Sprague-Dawley rats (250-300g) were divided into AMI-SHAM (undergoing sham surgery for AMI) and AMI (left coronary artery ligation) groups. Samples were collected three days post-AMI from blood, urine, heart, and renal tissues. Assessments included osmolality (plasma and urine), creatinine (plasma and urine), glomerular filtration rate (GFR), and tissue cytokine levels. Left ventricular end-diastolic pressure (LVEDP) represented cardiac function. Results are presented as mean ± standard error. Results: LVEDP measurements (mmHg) demonstrated similar results from SHAM (5.89 ± 0.61, n=14) and AMI groups (6.38 ± 0.43, n=6). Tumor Necrosis Factor-Alpha (TNF-α) levels (pg/mg of tissue) from the heart [SHAM (2.74 ± 0.50, n=10) vs AMI (5.05 ± 0.83, n=8)] and renal tissue [SHAM (2.37 ± 0.69, n=7) vs AMI (5.53 ± 0.41, n=5)] were significantly different (p<0.05) concerning their respective groups. Of note, molecular biochemical analyses revealed similar results. Plasma Osmolality (kgH2O): SHAM (310.8 ± 5, n=13) vs AMI (310.4 ± 2.57, n=10); Urinary Osmolality: SHAM (1653 ± 140, n=14) vs AMI (2054 ± 166.9, n=9); Plasma Creatinine (mg/dL): SHAM (0.35 ± 0.21, n=14) vs AMI (0.39 ± 0.25, n=10); Urinary Creatinine: SHAM (118.9 ± 12.35, n=14) vs AMI (126.5 ± 18.90, n=10). GFR (mL/min/100g) was also similar: SHAM (1.22 ± 0.18, n=14) vs AMI (1.22 ± 0.12, n=9). Conclusions: The study shows that the increase of TNF-α is contributing to the onset and progression of the pathophysiology of CS1, in line with the original hypothesis. On the other hand, because the three-day post-surgery timeframe addressed the primary mechanisms triggering the CS1, it seems that the functional impairment of the heart and kidneys was not manifest yet.

Support or Funding Information: FAPESP Process 2020/06043-7. CNPq Processes 306994/21-6 and 423999/21-4; FAEPA; CAPES/PROEX.

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.
Maternal Exercise Improves Infant Mesenchymal Stem Cell Lipid Storage and Oxidation, and Decreases Infant Adiposity
Authors: Claiborne Alex , Jevtovic Filip , Zheng Donghai , Biagioni Ericka , Wisseman Breanna , Krassovskaia Polina , Collier David
Published: May 2024

Rates of pediatric obesity are continuously rising and are likely to translate into high incidence of metabolic disease later in life. Maternal exercise during pregnancy has been established as a useful non-pharmacological intervention to improve infant metabolic health; however, mechanistic insight behind these adaptations remains mostly confined to animal models. Infant mesenchymal stem cells (MSCs) give rise to a multitude of infant peripheral tissue (e.g., skeletal muscle) and remain involved in mature tissue repair and maintenance. Importantly, these cells preserve the phenotype of an offspring donor and represent a model for the investigation of mechanisms behind infant metabolic health improvements. We used undifferentiated MSC collected during a randomized controlled trial to investigate if maternal exercise, regardless of exercise mode, affects infant adiposity and fatty acid oxidation. Compared to control, we observed >160% higher neutral lipid content in Ex-MSCs (p<0.01). However, this finding was coupled with significantly higher complete fatty acid oxidation to CO2 and lower incomplete fat oxidation (ASM production) in Ex-MSCs (p≤0.05). Infants in the exercise group had significantly lower body fat percentage compared to same age infants of controls at one month of age (p≤0.05). There was no difference in lean body mass volume (p>0.05) or infant one-month BMI (p=0.069). Together, these data indicate that maternal exercise exposure in utero is still associated with decreased infant adiposity one month after birth. MSC lipid content was positively associated with maternal fitness and exercise volume (p<0.01) during pregnancy. Finally, an increase in average maternal exercise volume (MET*min/wk; r=-0.4, p≤0.05) and total gestational MET*min (r=-0.36, p≤0.05), but not VO2max (p=0.07) was associated with infant 1-month body fat percentage. Together, these data showcase the influence of maternal exercise exposure on improvements in cellular metabolism and at 1 month of age. Collectively, our data suggests that exposure to maternal exercise could contribute to lower adiposity in early infancy.

This project was supported by the American Heart Association (18IPA34150006 to L.E.M.).

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.
Canine Cognitive Dysfunction Is Associated with Alzheimer’s Disease-Related Changes in the Brain Transcriptome and RNA Changes in Plasma Extracellular Vesicles
Authors: Osburn Shelby , McEntee Cali , McGrath Stephanie , Moreno Julie , LaRocca Thomas
Published: May 2024

Chronic, age-related diseases, such as Alzheimer’s disease (AD), can be diffcult to study longitudinally because humans have long lifespans and are highly heterogeneous. Recently, companion dogs have emerged as a promising model of AD because dogs: a) have a shorter lifespan than humans; b) are heterogeneous like humans; c) exposed to diverse human environments; and d) naturally develop canine cognitive dysfunction (CCD), similar to AD. However, the transcriptomic similarities between AD and CCD have not been evaluated, and emerging mechanisms of AD have not been explored in dogs. One such mechanism involves extracellular vesicles (EVs), ~100nm lipid bilayer particles that can package neurodegeneration-relevant cargo (e.g., RNAs, cytokines), export it to other cells, and contribute to aging/AD-relevant processes like inflammation. To better understand CCD and determine if EVs may play a role in it, we generated total transcriptome (RNA-seq) on cortex tissue and EVs isolated from plasma of young, old, and CCD dogs, and we evaluated cytokine expression in corresponding plasma samples via ELISAs. In the animals we studied, we observed functional differences between old healthy and CCD animals, reflected by Canine Dementia Scale scores (CADES; 6 and 57, respectively). In our RNA-seq analyses, we found marked age- and CCD-related transcriptome differences in the cortex (328 and 2673 differentially expressed genes, respectively), which mostly reflected changes in immune activation and neuronal health (similar to what has been observed in AD). Moreover, when we overlapped transcriptome data on the cortex and plasma EVs, we found a significant overlap in genes that were either up- or down-regulated in both samples (344 and 515, respectively). The processes related to these genes reflected changes in regulation of immune responses, as well as synaptic signaling. We also found evidence of CCL5 (RANTES, increased in AD) RNA in plasma EVs only in CCD samples, which corresponded with increased CCL5 expression in the brains of the same animals, although no differences were observed in plasma concentrations. While preliminary in nature, these results suggest that CCD is associated with AD-like transcriptomic changes in the brain, and with AD-relevant changes in EV cargo. Future studies are needed to determine the functional relevance of these data, but our results suggest the possibility of finding specific EV/RNA markers that could predict disease severity in CCD, and perhaps eventually in AD.

NIA R01AG078859; CSU Catalyst for Innovative Partnership 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.
Small-molecule AMPK activation preserves anabolic signaling in a C2C12 myotube cachexia model
Authors: Barbeau Jack E. , Stark Isaac S. , Summers Abigail E. , Gold Andrew B. , Dray Steven D. , Thomson David M.
Published: May 2024

AMP-activated protein kinase (AMPK) is a master metabolic regulator that responds to a decline in cellular energy status by promoting processes that generate ATP, while inactivating anabolic processes that consume ATP, thereby restoring the energy charge of the cell. In line with this general function, acute AMPK activation in healthy muscle cells potently inhibits anabolic signaling through the mechanistic target of rapamycin (mTORC1). However, treatment of atrophying muscle (from tumor-bearing mice and cells cultured in tumor cell-conditioned media) with the non-specific AMPK activator AICAR suggests that AMPK has a protective effect on muscle mass and anabolic signaling. We have identified MLX-0867 as a novel AMPK-activating small molecule (EC50 = 32.0 mM in C2C12 myotubes). We hypothesized that similar to AICAR, treatment with MLX-0867 would also preserve muscle mass and anabolic mTORC1 signaling in cultured muscle subjected to hyperinflammatory signaling. To test this, we treated C2C12 myotubes with control media (CM) or CM + 20 ng/mL TNF-ɑ and 100 U/mL interferon-γ (T/I) for 24 hours. Additionally, the cells were concurrently treated with 250 mM AICAR, 40 mM MLX-0867 (a novel AMPK activating small-molecule), or vehicle control during the treatment period. To visualize myotubes, myosin heavy chain (MHC) was detected by immunofluorescence, and average myotube diameter was measured. In a separate experiment, the protein was extracted from treated myotubes to determine the phosphorylation of p-70S6k and ribosomal protein S6 (rpS6) as markers of anabolic signaling through mTORC1. We found that T/I treatment significantly decreased myotube diameter. Neither AICAR nor MLX-0867 attenuated this atrophy. However, while T/I substantially reduced S6k and rpS6 phosphorylation, MLX-0867 (but not AICAR) partially preserved the phosphorylation of rpS6 and tended (p=0.11) to preserve p-70S6k phosphorylation under T/I treatment. In summary, MLX-0867 partially preserved anabolic signaling in T/I treated myotubes. However, this did not preserve muscle mass, at least under the conditions utilized in this experiment.

A Brigham Young University Widtsoe Grant and a sponsored research agreement with Biolexis Therapeutics funded this research.

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.
Transfer of Exercise-Microbiome Is Suffcient to Induce a Shift in the Skeletal Muscle Metabolomic Profile without an Exercise Stimulus
Authors: Kang Gyumin , Valentino Taylor , Wen Yuan , McCarthy John
Published: May 2024

Introduction: Skeletal muscle is a tissue that dynamically responds to disuse, which can induce rapid loss of mass and function. Identification of novel drug candidates will facilitate the development of supportive therapies for extended periods of decreased mobility, both planned and unanticipated. Recent findings from our lab as well as others indicate the important role of the gut microbiome in mediating the beneficial effects of exercise. Hypothesis: Transfer of microbiome from excise-trained mice into exercise-naïve mice will induce metabolic adaptations in the recipient skeletal muscle. Method: Sedentary and exercise-trained mice were used as donors for microbiome transfer. Exercise training consisted of 8-weeks of processive weighted wheel running. Exercise-naïve recipient mice were bowel cleansed with polyethylene glycol and transplanted with either sedentary (SED) or exercise-trained (EXER) donor microbiome. Recipient cecal content, serum, and gastrocnemius muscle were collected for untargeted metabolomics using liquid chromatography mass spectrometry. Results: Partial Least Squares Discriminant Analysis indicated significant metabolic discrimination between EXER and SED in all samples (cecal, serum, and muscle). Variable Importance in Projection scores identified several metabolites as significant discriminating metabolic features between EXER and SED, including ones involved in the TCA cycle, lysine and fatty acid degradation pathways. Conclusion: Transfer of microbial content from exercise-trained mice is suffcient to induce changes in muscle metabolite profile reminiscent of exercise in the absence of such a stimulus.

Funding: This work is supported by the National Institute on Aging (AG071888).

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.
Endurance training and essential amino acid intervention synergize to ameliorate fructose-induced metabolic dysfunction in mice
Authors: Kim Yeongmin , Kim Heejoo , Kang Minkyu , Yeom Taejin , Khin Phyu Phyu , Roy Sampriti , Wolfe Robert R
Published: May 2024

Purpose: Excessive fructose (FRU) consumption can rapidly produce multiple features of metabolic syndrome, including dysregulation of systemic metabolism, insulin resistance, and diabetes. Essential amino acids (EAAs) and endurance exercise training (ET) improve abnormal metabolism in various disease conditions, yet their combined effect and metabolic mechanism remain unclear. Thus, the current study aimed to investigate metabolic kinetic mechanism and the combined effect of EAA and ET on fructose-induced metabolic dysfunction. Materials and methods: Mice were randomly divided into 5 groups with an 8-week intervention: normal chow (CON), FRU, FRU+ET, FRU+EAA or FRU+ET+ EAA, followed by stable isotope tracer infusions ([U-13C16]palmitate, [D2]glucose, and [D5]glycerol) or D2O administration to determine substrate metabolic flux rates and their contribution to TCA cycle flux and protein synthesis rates of various organs, respectively. Summary of results: FRU-induced adverse changes in body weight and physical function were reversed by ET, EAA, or ET+EAA. In stable isotope tracing analysis, ET and ET+EAA alleviated hyperglycemia by suppressing hepatic glucose production rate, while EAA and ET+EAA normalized palmitate turnover and contribution to TCA cycle in various organs. Additionally, the altered protein synthesis measured using a D2O labeling method was normalized by ET and ET+EAA. Conclusion:These findings suggest that the combined treatment of dietary EAAs and ET more effectively mitigates fructose-induced metabolic dysfunction by normalizing hepatic glucose production rate, protein synthesis rates, and fatty acid metabolism.

This research was supported by a grant of the Korea Health Technology R&D Project through the Korea Health industry Development Institute (KHIDI), funded by the Ministry of Health & Welfare, Republic of Korea (HI22C2208), and the National Research Foundation of Korea (NRF), funded by the Korea government (MSIT) (No. 2021R1A2C3005801), and partially funded by MYOCARE INC.

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.
Interleukin-1β triggers muscle-derived extracellular superoxide dismutase expression and protects muscles from doxorubicin-induced atrophy
Authors: Okutsu Mitsuharu , Yamada Mami
Published: May 2024

Oxidative stress plays an important role in skeletal muscle atrophy. Doxorubicin, a conventional chemotherapeutic agent prescribed for cancer, causes skeletal muscle atrophy and adversely affects mobility and strength. Since doxorubicin-induced muscle atrophy is primarily attributable to oxidative stress, its effects could be mitigated by antioxidant-focused therapies; however, these protective therapeutic targets remain ambiguous. This study aimed at demonstrating that doxorubicin triggered severe muscle atrophy via upregulation of oxidative stress (4-Hydroxynonenal and Malondialdehyde) and atrogenes (Atrogin-1/MAFbx and Muscle RING Finger-1) in association with decreased expression of the antioxidant enzyme, extracellular superoxide dismutase (EcSOD), in cultured C2C12 myotubes and mouse skeletal muscle. EcSOD recombinant protein supplementation elevated EcSOD levels on the cellular membrane of cultured myotubes, consequently inhibiting doxorubicin-induced oxidative stress and myotube atrophy. Furthermore, doxorubicin treatment reduced interleukin-1β (IL-1β) mRNA expression in cultured myotubes and skeletal muscle, while transient IL-1β treatment increased EcSOD protein expression on the myotube membrane. Notably, transient IL-1β treatment of cultured myotubes and local administration in mouse skeletal muscle attenuated doxorubicin-induced muscle atrophy, which is associated with increased EcSOD expression. Collectively, these findings reveal that the regulation of skeletal muscle EcSOD via maintenance of IL-1β signaling is a potential therapeutic approach against doxorubicin-and oxidative stress-mediated muscle atrophy.

This study was supported by Grant-in-Aid for Scientific Research (B) (15H03080, 18H03153, 21H03326), Grant-in-Aid for Exploratory Research (20K21766), Suzuken Memorial Foundation, Toyoaki Scholarship Foundation, The Nakatomi Foundation, and The Uehara Memorial Foundation (to M.O.). This research was also supported by Grant-in-Aid for JSPS Fellows (20J15551), Grant-in-Aid for Early-Career Scientists (22K17733), Suzuken Memorial Foundation, The Nakatomi Foundation, and The Uehara Memorial Foundation (to M.Y.).

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.
Endothelin-A Receptor Activation Stimulates Th17 Cell Differentiation
Authors: Luong Tha , Molina Patrick , Colson Jackson , Pollock David , Pollock Jennifer
Published: May 2024

Th17 cells are a major contributor to many pro-inflammatory disease conditions. Endothelin 1 (ET-1) through the ETA receptor promotes inflammation, however its role in T cell differentiation, especially T helper 17 (Th17) cells, is not fully understood. Importantly, ET-1 has been shown to be elevated in people with autoimmunity, diabetes, and salt-sensitive hypertension in which augmented Th17 cells are known to contribute to the pathogenesis. Therefore, we hypothesized that ETA receptor activation mediates Th17 cell differentiation. To test our hypothesis, we first treated C57BL/6J male mice (8–12-week-old, normal chow) with the ETA receptor antagonist (ABT-627, 10mg/kg/day) in the drinking water for five weeks. We measured Th17 cells in the colon and kidneys by flow cytometry. We found that ETA receptor blockade reduced the number of Th17 cells compared to that in vehicle control mice. Indeed, the absolute number of Th17 cells decreased from 461±61 Th17 cells/per two kidneys in vehicle control to 146±29 Th17 cells per two kidneys in the ABT-627 treated group (p=0.004), and from 8372±1454 Th17 cells to 3378±936 Th17 cells (p=0.028) in the whole colon. To determine whether this observation is a direct effect on IL17A induction, we evaluated ETA receptor antagonism under Th17 polarizing conditions in vitro. Naïve CD4+ T cells were isolated from the spleen and cultured under Th17 polarizing conditions (TGFβ and IL-6) in the presence or absence of ETA receptor antagonist (BQ-123, 1μM). We found that ETA receptor blockade directly attenuated Th17 differentiation in vitro. The frequency of IL17A-expressing cells within CD4+ T cells reduced from 11.37±0.68% in media control to 9.87±0.60% in BQ-123 treated cells (p=0.0006). Similarly, the relative mean fluorescence intensity (MFI) analysis revealed a reduction in IL17A production following ETA receptor blockade from 8937±871 relative units in media control to 7132±725 relative units in BQ-123 treated cells (p=0.0136). These data taken together support our hypothesis that the ETA receptor plays a key role in Th17 differentiation. Because of the critical role of Th17 cells in pathophysiology, our findings warrant further investigations for the use of ETA receptor antagonist in pro-inflammatory conditions.

Tha Luong - U2C/TL1 Deep South KUH PRIME U2C DK133422 & TL1 DK139566 from the NIH/NIDDK Patrick Molina - F31HL151264 David & Jennifer Pollock - R01 DK134562.

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.