bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessment of Mitochondrial Function in a Mouse Model of Mild Chronic Kidney Disease Induced by High-Fat and High-Salt Diet
Authors: Paula Venisia , Decker Stephen , Stuart Deborah , Opurum Precious , Ramkumar Nirupama , Funai Katsuhiko
Published: May 2024

Intro: Kidneys are known for high energy demands involved in active transport and are thus highly oxidative organs, consuming the second-highest amount of oxygen per gram of tissue at rest (only exceeded by the heart). Chronic kidney disease (CKD) is a complex disorder that presents substantial challenges in understanding its pathophysiological mechanisms, including mitochondrial alterations. However, there are no established mouse models that recapitulate the CKD phenotype observed in humans.Hypothesis: We hypothesized that a high-fat, high-salt diet would induce a mild CKD phenotype and mitochondrial dysfunction in mice. Methods: We subjected C57Bl/6 mice to a high-fat (42%) and high-salt (8% NaCl) diet (HF/HNaCl) or standard chow diet for 16 weeks (n=4 per group). Additionally, we conducted comprehensive investigations into mitochondrial function, focusing on state 3 mitochondrial oxygen consumption (Oroboros O2K) and adenosine triphosphate (ATP) production (Horiba Fluoromax). Differences between groups were determined using Student’s t-tests. Results: HF/HNaCl feeding resulted in polyurea indicated by an increase in 24-hour urine output (Chow: 1.5 ± 0.2 mL; HF/HNaCl: 3.7 ± 0.8 mL; p=0.05) and a 30% reduction in glomerular filtration rate compared to chow-fed animals (Chow: 911.2 ± 107.8 μL/min/100g; Hf/HNaCl: 639.5 ± 25.9 μL/min/100g; p=0.08), indicative of the development of mild kidney disease. Although subtle changes were observed in mitochondrial oxygen consumption and ATP production, the alterations were not statistically significant. Discussion: Our findings suggest that the induced mild CKD state via the dietary regimen led to moderate renal impairment without substantial impacts on mitochondrial respiratory capacity and ATP synthesis. The establishment of this mouse model provides a valuable platform for further investigations into the complex interplay between renal dysfunction and mitochondrial dynamics in the context of mild CKD, offering insights that may pave the way for the development of targeted therapeutic interventions for this prevalent and debilitating condition.

This project was supported by grants from the National Institutes of Health.

This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.
OxLDL/LOX-1 Mediated Sex, Age, and Cell Dependent Alterations in Mouse Thoracic Aortic Vascular Reactivity, Stiffness, and Remodeling
Authors: Wendt Trevor , Gonzales Rayna
Published: May 2024

Elevated oxidized low-density lipoprotein (oxLDL) is a risk factor and component that worsens cardiovascular disease states. OxLDL can elicit its detrimental action, via lectin-like oxLDL receptor 1 (LOX-1) and has been shown to disrupt vascular function. In this study, we determined whether oxLDL, via LOX-1, alters aortic vascular reactivity and determined if sex differences exist. Thoracic aortic endothelium-intact or -denuded ring segments were isolated from intact C57BL/6J female and male mice and incubated with oxLDL ex vivo (50ug/dL; 2h). Using wire myography, cumulative concentration-response curves to phenylephrine (PE) were generated to determine contractile responses. From these curves, the EC50 was determined and used to contract rings to assess acetylcholine (ACh) dependent relaxation. Calculated aortic stiffness and remodeling, as well as mRNA expression of vasoactive and pro-inflammatory mediators were assessed. BI-0115 (10μM; selective LOX-1 inhibitor) was used to determine LOX-1 dependence. In this study, we investigated the effects of oxidized low-density lipoprotein (oxLDL) via the LOX-1 receptor on murine thoracic aortic vasoreactivity, stiffness, and remodeling across age and sex. Our results demonstrate a differential sex, age, endothelial cell, and LOX-1 dependent alterations to the effcacy of PE-induced contractile responses and ACh-mediated vasorelaxation in the thoracic aortic rings following oxLDL exposure. Additionally, we observed a distinct sex and age effect on thoracic aortic stiffness following exposure to oxLDL. There was also a sex effect on calculated vessel diameter, as well as an age effect on oxLDL-mediated inward remodeling that was LOX-1 dependent. We also observed an oxLDL and age dependent increase in LOX-1, IL-6, endothelin-1 (ET-1), and ET-1 receptor alpha and beta mRNA expression. Thus, LOX-1 inhibition and the resulting attenuation of oxLDL/endothelial-mediated alterations in aortic function suggests that there are differential sex differences in the role of oxLDL/LOX-1 in the thoracic aorta of male and female mice. In conclusion, acute exposure to oxLDL led to altered vasoreactivity, endothelial dysfunction, and changes in aortic stiffness and remodeling. These effects were in-part age, sex, endothelial, and LOX-1 dependent. This study reveals potential complex interactions in oxLDL/LOX-1-mediated vascular responses that could serve as potential therapeutic intervention for vascular diseases such as atherosclerosis.

University of Arizona Valley Research Partnership Grant VRP37 P2 (RJG), American Heart Association 19AIREA34480018 (RJG), UA VRP Grant VRP55 P1a (TSW).

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.
Coronary Vascular Rarefaction in Heart Failure
Authors: Fopiano Katie Anne , Hardell Davis J , Patel Vijay S , Bagi Zsolt
Published: May 2024

Coronary vasculature rarefaction has been thought to play a role in the development of heart failure (HF), causing reduced myocardial perfusion; understanding the role that coronary rarefaction plays within HF presents an avenue for therapeutic strategies. We assessed the coronary microvascular and small vessel networks in left atrial appendage (LAA) samples to determine differences based on HF status. LAA samples were obtained from 15 consecutive patients during cardiac surgery (BMI: 22.8-37.9, age: 51-82, M:F: 9:6, NonHF:HF: 11:4). LAA samples were paraffn-embedded or flash frozen whereby 40 μm thick sections were then immunolabelled using DyLight 594 fluorescent tomato-lectin dye and z-stack images were rendered using microscopy. Z-stack images were input into Vesselucida360 and the vessel networks were three-dimensionally reconstructed via unbiased automatic tracing with multiple quantitative endpoints calculated. LAA samples were also used for proteomic analysis via LC-MS followed by statistical and pathway analyses to determine differences in protein expression and pertinent pathways as well as in a wide-scale gene expression array (NanoString) to further study underlying molecular targets. We found that the number of branching nodes and total vessel length in the coronary vascular network was decreased in HF compared to NonHF patients. Whereas the total volume and surface area were similar between HF and NonHF patients. Proteomic analysis and principal component analysis identified differences in protein profiles in the two groups, with pathway analysis identifying cardiac contraction and metabolism, along with hydrogen peroxide catabolic pathways downregulated in HF. Gene expression profiling identified numerous hypoxia response and oxidative stress response markers as downregulated in HF LAA samples. The data obtained show coronary vascular rarefaction occurring in HF patients, implying potential implications in the progression of HF. Additionally, proteomic data point to the downregulation of hydrogen peroxide response pathways as a potential mechanism for coronary microvascular rarefaction that we want to elucidate in future studies.

T32 HL155011 (KAF) F31 NS132564 (KAF).

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.
Role of CFTR in Polycystic Kidney Disease
Authors: Cebotaru Liudmila , Ciobanu Cristian
Published: May 2024

Introduction: Polycystic kidney disease (PKD) causes numerous cysts to grow in the kidneys, liver and pancreas. These cysts are filled with fluid. In the United States about 600,000 people have PKD, which is the fourth leading cause of kidney failure. The two main types of PKD are autosomal dominant PKD (ADPKD), which is usually diagnosed in adulthood and autosomal recessive PKD (ARPKD), which can be diagnosed in the womb or shortly after a baby is born. ADPKD is associated with the slow but relentless formation of multiple renal cysts. CFTR is known to be involved in secreting fluid in ADPKD through its localization in the apical membrane. Thus, the plasma membrane is the expected site where CFTR functions. Here, we show that CFTR unexpectedly is located in primary cilia and plays a role in cilia length. ARPKD is associated with systemic and portal hypertension, fibrosis of the liver and kidney and enlarged kidneys, with fusiform dilation of the collecting ducts. Although it has been postulated that CFTR plays a role in fluid secretion in ADPKD, the opposite is true in ARPKD. For example, a double mutant of CFTR and polycystin/polyductin mice develop massively enlarged kidneys and die from renal failure at ~24 days after birth (Nakanishi et. al (2001). J. Am. Soc. Nephrol. 12, 719-725). Thus, knocking down CFTR makes the disease worse. Methods: We used for ADPKD a mouse model bearing the R3277C mutation in PC1 and ARPKD mouse model bearing pkhd1Pkhd1del3-4/del3-4 deletion. We injected male and female mice with 30 mg/kg of VX-809 every other day. Also, we injected ADPKD and ARPKD mice once with AAV1 del27-264CFTR at 30 days old and sacrificed at 90 days. Results: Cyst areas are significantly reduced in kidney and liver after treatment with VX809 or with AAV1 del27-264CFTR. Conclusion: These data indicate that VX-809 reduces proliferation and the presence of CFTR at the apical membrane while increasing CFTR at the basolateral membrane in kidney in ADPKD model and liver in ARPKD model. Demonstration of kidney and liver cyst reduction increases the therapeutic potential of VX-809 as a treatment of ADPKD and ARPKD. Also we are reporting direct evidence of involvement of CFTR in cyst reduction in liver and in kidney by using gene therapy method treating ADPKD and ARPKD mice with AAV1 del27-264CFTR which would bind to WTCFTR and correct the traffcking of CFTR in ADPKD and ARPKD mice.

NIH and PKD Foundation.

This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.
Identifying Cell Population Heterogeneity in Cerebral Palsy Muscle
Authors: Stewart Madison , Hu Lin-Ya , Kulkarni Vedant , Smith Lucas
Published: May 2024

Cerebral Palsy (CP) is a neuromuscular condition that affects movement and muscle tone, and often leads to contractures. Muscle satellite cells (MuSCs) have been shown to decrease in CP, but the overall resident muscle cell populations have not been characterized. Our objective is to identify differences in the cell populations and transcriptomes of muscle biopsies taken from CP and typically developing patients (TD) using single cell RNA sequencing. We hypothesize that cells taken from CP patient muscle will have a different distribution amongst populations. Gene enrichment, psuedotime analysis, subclustering, and interactome analysis were conducted to investigate muscle resident cell populations. The results demonstrated that, while there was not a significant disparity between cell populations of CP and TD muscle, there were differences in the subpopulations of MuSCs and fibro-adipogenic progenitors (FAPs). These results indicate that FAPs from CP patients tend to be more pro-fibrotic and may signal to MuSCs to undergo apoptosis. This study may help to identify molecular and cellular targets for CP therapies.

Funding provided by the Hartwell Foundation.

This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.
How They Eat: An Examination of Digestive Physiology of Sympatric Prickleback Fishes
Authors: Steinmann Kaitlyn , Ye Tim , Saleh Sara , Herrera Michelle , German Donovan
Published: May 2024

How fishes thrive on different diets is not understood as well as for terrestrial animals. Thus, examining the flexibility of gut function in fishes with different diets provides insight into dietary specialization in the largest vertebrate class. In this study, we measured the amylolytic activities in the guts of closely related, sympatric species: Xiphister mucosus (herbivore), X. atropurpureus (omnivore), Phytichthys chirus (omnivore), and Anoplacharus purpurescens (carnivore). For all species, the amylase activity decreased moving distally along the intestine, but less so for the carnivorous A. purpurescens. Overall, our results—more elevated amylase activity in those fish eating more algae—agree with the Adaptive Modulation Hypothesis (AMH), which suggests that there should be a match between enzymatic activity and dietary substrate intake. Measurements of proteases and lipases are in progress, but we anticipate some support for AMH in other enzyme classes. Moreover, we are also measuring these same enzyme activities in these same species fed omnivorous or carnivorous diets in the laboratory. The flexibility of the intestines of the fish species to accommodate different food types provides insight into their roles in the ecosystems and how fixed the vertebrate digestive system can be.

NSF IOS 1355224 Undergraduate Research Opportunity Program at University of California, Irvine.

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.
A Comprehensive Approach to Graduate Education in the Biomedical Sciences
Authors: Dent Elena , Crider Emily A , Sullivan Jennifer
Published: May 2024

There are roughly 130 biomedical sciences-related PhD training programs in the U.S. with about half of the graduates remaining in academia post-graduation. Biomedical sciences PhD programs emphasize rigorous training in research to prepare students to enter academia but may lack training in other areas that contribute to career success. Trainees face many challenges in graduate school, including meeting the basic scientific knowledge and research milestones, developing strong communication skills, and enriching their skillset through professional and career development opportunities to best position themselves for future success. To accomplish all of this while maintaining a healthy sense of self can be daunting. The Graduate School (TGS) at Augusta University (AU) aims to facilitate ground-breaking research alongside outstanding education by providing a holistic and comprehensive graduate experience. TGS is currently undergoing review and revision of three of the four arms of graduate education: academics, research, student well-being, and professional development. We use data collected from an external review and 52 currently enrolled and previously graduated (within 3 years) biomedical sciences PhD students to identify opportunities for improving the first-year core curriculum at AU. In response, TGS developed a first-year core curriculum committee tasked with reviewing, revising, and addressing gaps in the first-year core curriculum. Furthermore, TGS has developed and launched GradWell, a health and wellness initiative, and has also partnered with external collaborators to offer strategic professional development opportunities to biomedical sciences students, prioritizing holistic growth to enhance the student experience. Continuous programmatic evaluation related to curriculum, student well-being, and professional development is critical to ensure programs are meeting the evolving needs of students while incorporating innovative pedagogy to maximize training opportunities and the development of well-rounded research scientists.

This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.
Novel, engineered fusogenic liposome-based anti-oxidant delivery system improves the blood-brain barrier integrity in aging
Authors: Shanmugarama Santny , Csik Boglarka , Nyúl-Tóth Ádám , Gronemann Till , Gulej Rafal , Tarantini Stefano , Ungvari Zoltan
Published: May 2024

Vascular dysfunction plays a pivotal role in age-related cognitive decline and neurodegeneration. The aging process often leads to a loss of integrity in the blood-brain barrier (BBB), initiating neuroinflammation and contributing to a decline in cognitive function. In previous research, we demonstrated the potential of resveratrol (RSV), a natural polyphenol, to target cerebromicrovascular endothelial cells (CMVECs), effectively countering age-related oxidative stress and improving vascular function, both in vitro and in vivo. However, the limited bioavailability of resveratrol raised questions about its effectiveness concerning the BBB and neuroinflammation. Our study aimed to address this challenge by introducing a novel drug delivery system designed to enhance the effciency of polyphenol delivery. This innovative approach involved the use of fusogenic liposomes (FL) integrated with a bioengineered protein corona (PC) featuring specific apolipoprotein E (ApoE). Our central hypothesis posited that PC formation could be harnessed to directly target CMVECs and enhance liposomal uptake, with the ultimate objective of effectively delivering RSV to the brain's microvessels in aging subjects (ApoE-FL-RSV). Our investigation encompassed the characterization of ApoE-FL uptake by CMVECs, along with an analysis of its biodistribution and pharmacokinetics in vivo. Remarkably, our findings revealed a significant increase in ApoE-FL-RSV accumulation within CMVECs in vivo, compared to control FL uptake. We employed advanced in vivo multiphoton imaging to longitudinally monitor the effects of ApoE-FL-RSV on the BBB, which demonstrated a significant rejuvenation of the endothelial barrier function in aged mice treated with ApoE-FL-RSV. In light of these results, we concluded that the fusogenic liposomal delivery system holds promise as a viable pharmacological intervention for addressing age-related vascular cognitive impairment.

AHA834339, RF1AG072295, R01AG055395, R01AG068295; R01AG070915, K01AG073614, R01NS100782, R01CA255840, and Presbyterian Health Foundation.

This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.
The Use of Milk Bovine Extracellular Vesicles to Mitigate Gut-Liver Axis Dysfunction Under Pediatric Parenteral Nutrition
Authors: Antunes Karen , Mims Tahliyah , Leathem Cameron , Willis Nathaniel , Pierre Joseph
Published: May 2024

Parenteral Nutrition (PN) is a lifesaving strategy that provides intravenous nutrition in patients when enteral feeding is contraindicated, or access is insuffcient to prevent malnutrition. PN is used in low-birth-weight neonates whereprolonged use is associated with severe metabolic complications, including parenteral nutrition-associated liver disease (PNALD). PNALD is characterized by hepatitis, cholestasis, fibrosis, steatosis, and eventual organ failure. Elevated rates of PNALD in pediatric patients may be driven by liver immaturity, aberrant metabolic adaptation, and leaky gut barrier.To characterize the etiology of PNALD, we recently established a pediatric mouse model of PN. Using this model, we explored the intravenous use of bioactive milk components to augment hepatic immune response in pediatric mice without enteral milk intake. Extracellular vesicles (EVs) are involved in cell-to-cell communication, contain immune-augmenting microRNA, and are enriched in bovine milk. After isolating EVs from bovine milk and characterizing them, we explored EV use in vitro via M1 macrophage responses, showing TNF-alpha inhibition in the presence of LPS. Wethen hypothesized that EVs would protect the pediatric liver from hepatitis under PN feeding in vivo. Mouse pups were randomized to intravenous PN, PN + EV (1.39x109 particles/uL), or sham surgery control for 6 days. Flow cytometry showed PN elevated hepatic macrophages (CD11b+F4/80+), myeloid-derived suppressor cells (CD11b+GR1+) andreduced relative T cell populations compared with sham controls. PN+EV treatment restored hepatic immune profiles to patterns observed in sham controls. Spleen and liver cytokines also mirrored changes in hepatic flow results, where elevated proinflammatory IL-1 beta was induced with PN alone, but similar levels were found in sham and PN+EVanimals. MicroRNA sequencing showed the EV isolates contain 48% Let-7, a described myeloid suppressor microRNA. This data demonstrates that intravenous EV administration - or future synthetic microRNA - may provide a noveltherapeutic approach for patients requiring PN nutrition support, especially those with elevated risk of PNALD induced inflammation and organ dysfunction.

Dairy Innovation Hub, UW-Madison.

This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.
Age-Related Vascular Mitochondrial Dysfunction Is Ameliorated by Time-Restricted Feeding Intervention
Authors: Sanford Madison , Negri Sharon , Reyff Zeke , Ballard Cade , Nyul-Toth Adam , Gulej Rafal , Brown Jacob
Published: May 2024

Endothelial dysfunction constitutes a hallmark of vascular aging that can have serious implications for disease risk. In addition, aging is associated with mitochondrial dysfunction, which can lead to increased oxidative stress and create associated damages. Time-restricted feeding (TRF) is a dietary intervention known to have many benefits on age-related disease risk. The objective of this study is to elucidate the effects of TRF upon endothelial mitochondrial function of aorta during aging. We hypothesized that TRF protects the aorta from age-related endothelial mitochondrial dysfunction. Adult C57BL/6 mice underwent TRF regimen, including six hours of ad libitum feeding daily. Young and age-matched control mice were fed ad libitum. After 12 months of TRF, wire myography was performed on aorta tissue as a measure of endothelial function. The aorta received pharmacological treatments to induce contraction, and dose-dependent dilation was quantified. For the first time, simultaneous measurement of reactive oxygen species (ROS) and oxygen consumption were completed in aorta tissue using Oroboros O2K Fluorespirometry. Dihydroethidium (DHE) fluorescent staining of ROS in aorta tissue was used to validate ROS measurements from O2K. Serum ketone body levels related to metabolic switching and relevant to mitochondrial biogenesis were determined. TRF improved endothelial-dependent dilation of aorta tissue, representing the intervention’s protection of endothelial function in aging. Aged TRF mice had greater oxygen consumption and less ROS in aorta tissue than age-matched control mice, indicating improved vascular mitochondrial function after TRF intervention. Aged TRF mice had elevated serum levels of ketone bodies involved in mitochondrial biogenesis. This supports the hypothesis that age-related changes in vascular mitochondrial health are alleviated by TRF. The knowledge gained from this study is relevant to understanding the mechanisms of age-related vascular dysfunction.

Stephenson Cancer Center, National Institute of Aging R03 AG070479, American Heart Association.

This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.
Sex Differences in Kidney Damage in BUF/MnaMcwi Rats
Authors: Royster Darcel , Kwitek Anne , Holl Katie , Wagner Valerie
Published: May 2024

Kidney disease is commonly found in the BUF (Buffalo) strain of rats. It has been observed that male BUF rats show signs of focal glomerulosclerosis (FSGS). They are known to have proteinuria, hypoalbuminemia, and hyperlipidemia as they age. This is preceded by renal macrophage activation and Th2 lymphocyte polarization. There is no prior literature that explores kidney disease in female BUF rats.We previously observed that kidneys in female BUF rats appeared more damaged than their male mates, leading to the hypothesize that the female BUF/MnaMcwi (BUF) breeder rats have greater kidney damage features than male mates. To determine the relationship between sex and function, we collected urine samples using metabolic cages (at 12, 17, and 23 weeks of age), harvested organ tissue (heart left, ventricle, spleen, thymus, and kidneys), and used histopathological examination of formalin-fixed paraffn-embedded kidney samples to determine cortex tubule damage and glomerular area. We expected to see sex differences in relative sizes (mg/g BW) of the thymus, heart left ventricle, kidneys, and spleen. We found that the male BUF rats had larger absolute body weight (g), as expected. We also found that there were no significant sex differences in relative sizes (mg/g BW) of the thymus, heart left ventricle, and spleen. There was a significant sex difference in relative total kidney size (mg/g BW), with the females having larger kidney sizes compared to their body weight. In addition, there was increased microalbumin in the female BUF overnight urine collection that was significantly higher than the male BUF rats. There was no significant sex difference in the microalbumin: creatinine ratio. Finally, we found no significant sex difference in cortex tubular damage between the age-matched BUF rats, but there was a significant difference in glomeruler area (mm 2), with male glomeruler areas being significantly larger. Future studies will be done to replicate the findings and determine if virgin females show the same results.

ASPIRE Program (R25HL 168782) Medical College of Wisconsin.

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.
Electronic cigarette-induced adipose tissue inflammation is rescued by acipimox
Authors: Gilbertson Robert F. , Xu Justin , Rivera Juan Carlos , Hasan Kamrul M. , Sinha-Hikim Amiya P. , Shao Xueshi M. , Espinoza-Derout Jorge
Published: May 2024

Objective: Electronic cigarettes (e-cigarettes) are the most commonly used tobacco product in the U.S. with high frequency among youth. Our laboratory has shown that e-cigarettes induce metabolic changes and cardiac dysfunction associated with elevated serum free fatty acids (FFAs). Adipose tissue dysfunction is a proinflammatory state that mediates multiple pathogenic mechanisms in the well-known associations between cardiovascular pathology, hypertension, and metabolic syndrome. In adipose tissue, crown-like structures (CLSs) are signs of metabolic dysfunction and adipose tissue inflammation. CLSs are composed of macrophages surrounding dead or dying adipocytes. Hypothesis: We hypothesize that e-cigarettes produce inflammation in adipose tissue, which is mediated by lipolysis. Methods: C57BL/6J wild-type mice on high fat diet were treated with saline aerosol, e-cigarette with 2.4% nicotine [e-cig (2.4%)], and e-cig (2.4%) plus acipimox (an inhibitor of lipolysis) [e-cig (2.4%)+ACIP], for 12 weeks. Adipose tissue was stained with Hematoxylin and Eosin (H&E). CD45 is the surface marker of immune cells. Therefore, we quantified the number of CD45+ cells in adipose tissue. Additionally, we performed a transcriptomic evaluation with Gene Set Enrichment Analysis (GSEA). Results: H&E staining showed abundant CLSs in mice exposed to e-cigarettes in adipose tissue. The number of CLSs was normalized in the e-cig (2.4%)+ACIP group. E-cigarettes induced an increase of CD45+ cells in adipose tissue, which was also normalized by acipimox. GSEA of the RNA-seq data revealed upregulation of inflammatory pathways in adipose tissue from e-cigarette-treated mice, including Interferon-g and Interferon-a response, which were rescued by acipimox treatment. Summary: Inhibiting lipolysis with acipimox normalizes the inflammatory changes induced by e-cigarettes in adipose tissue. These findings suggest a functional interplay between adipose tissue and metabolic dysfunction caused by e-cigarettes.

Funding: JE-D work was supported by the NIH grants: NIGMS (SC2GM135127), NIMHD (S21MD000103), the CDU Accelerating Excellence in Translational Science (AXIS) (U54MD007598-14S2), and a voucher from UCLA CTSI (UL1TR001881). TCF was supported by the California TRDRP grant (28CP-0040), DODCDMRP grant (PR190942), and NIDA (R25DA050723) grants. XMS was supported by a NIDA (R42DA044788) grant. KPR was supported DODCDMRP grant (PR190942-P1).

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.
Retrograde optimized AAV tracer fails to transduce dorsal raphe nucleus projections to the basolateral amygdala
Authors: Hammack Robert , Daws Lynette , Toney Glenn
Published: May 2024

Key in aversive emotional states are serotonergic (5-HT) projections to the basolateral amygdala (BLA) originating from the dorsal raphe nucleus (DRN). Despite being critical in aversive states, the precise anatomical location of 5-HT DRN neurons that project to the BLA is not well delineated. Vital in recent advancements in neuroscience are neurotropic adeno-associated viral (AAV) vectors, which allow for long-term expression of transgenes. However, a recent study using retrograde transport optimized AAV (rAAV2-retro) tracers has shown that transfection of axon terminals and subsequent retrograde transport may not be as ubiquitous as traditional non-transgenic tracer techniques. In this study, we wanted to not only map the precise location of neurons within the DRN that project to the BLA but also test the extent to which rAAV2-retro vectors were useful tools to study these projection neurons. In C57 mice, we iontophoretically deposited (+3-μA positive current at 7s intervals for 10 min, n=3 mice) or pressure nanoinjected (100 nl, n=3 mice) rAAV2-retro expressing the fluorescent reporter GFP (rAAV2-retro-CAG-GFP) into the BLA. After allowing two weeks for GFP expression, coronal sections were prepared from perfusion-fixated tissue and GFP expression was assessed in the DRN as well as the medial entorhinal cortex (mEC), a well validated input to the BLA. We found that iontophoretic deposition failed to robustly label the DRN and mEC. In contrast, while pressure nanoinjection failed to label many DRN neurons, the mEC was robustly labeled. These results may suggest a lack of DRN axon terminals within the viral injection sites or a failure of AAV retrograde tracer transduction in DRN projections to the BLA. Future studies comparing traditional retrograde tracer techniques to our results are warranted. In sum, these results caution the use of rAAV2-retro vectors to study DRN inputs to the BLA.

MH093320 (LCD & GMT).

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.
A novel preclinical model of fentanyl-induced cardiorespiratory collapse to investigate resuscitation outcomes
Authors: Piao Lin , Fang Yonghu , Garcia Alfredo J. , Sharp Willard
Published: May 2024

Introduction: Opioid-related morbidities have become a critical public health concern, with ultrapotent synthetic opioids (UPSO) such as fentanyl contributing to the rise in opioid-related fatalities. Respiratory depression is the cardinal trait of fentanyl overdose, leading to systemic hypoxia and subsequent cardiorespiratory collapse (CRC). There is growing recognition that fentanyl induced CRC (fiCRC) is unique from other forms of sudden CRC. Yet, the consequences of fiCRC and its reversal remain poorly understood. This is due in part to the limited preclinical studies investigating rescue from fiCRC. Objective: using a novel model of fiCRC and subsequent reversal, this ongoing study aims to define the impact of UPSO and naloxone rescue on in vivo survival outcomes. Methods and Results: Male and female C57BL/6J mice were used. UPSO fentanyl i.v. administration (30 to 500 mcg/kg) suppressed breathing and subsequently led to fiCRC. The return of spontaneous circulation (ROSC) was achieved by performing manual chest compressions in combination of epinephrine administration after 8 minutes of fiCRC. In subset of mice, naloxone was administered post ROSC. Outcomes after 72 hours were accessed. The latency of fiCRC (mean arterial pressure at 40 mmHg) exhibited a negative correlation with the doses of fentanyl administered. Resuscitation from fiCRC was unreliable across the dose spectrum, while naloxone consistently rescued the majority of fiCRC animals. Naloxone increased ROSC rate from 54% to 86% when the dose of fentanyl was 30 mcg/Kg (n=22). With naloxone rescue, we compared fiCRC with non-opioid-induced cardiac arrest followed by potassium chloride injection (0.8 mg/g). Both models showed severe lung edema as evidenced by Evans Blue staining. However, the lung wet/dry weight ratio was higher in fiCRC group than in the non-opioid treatment group (5.50±0.05 vs. 6.60±0.60, n=4, p<0.05). Survival in fiCRC group was significantly worse than in non-opioid treatment group (survival rate: 25% vs. 83%, n=17, p<0.05). Conclusions: Our study highlights two important findings. First, the reliable resuscitation of fiCRC necessitates the use of naloxone. Second, the likelihood of injury is significant following successful rescue from fiCRC by naloxone. Our continued work using this fiCRC model will lead to insights that can be leveraged for strategies to mitigate injury and improve survival following fentanyl overdose.

R01 HL163965 & R01 DA057767.

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.
Regeneration of Neuromuscular Synapses by Inhibition of the Prostaglandin Degrading Enzyme 15-PGDH
Authors: Monti Elena , Afshar Mohsen , Wang Yu Xin , Su Shi Qi , Kraft Peggy , Alexandrova Ludmila , Wheeler Joshua R.
Published: May 2024

Background: Skeletal muscles require voluntary activation to move, which is supplied via motor neurons. The terminal axons of motor neurons innervate muscle fibers at the neuromuscular junction (NMJ). NMJ degeneration increases with age and injury, decreasing muscle contractility and strength and severely reducing individuals’ quality of life. Treatments able to restore NMJ integrity and muscle innervation after injury and in aging are currently lacking. Aim: Our lab has recently shown that boosting prostaglandin E2 (PGE2) levels in aged mice by inhibiting its degrading enzyme 15-prostaglandin dehydrogenase (15-PGDH) stimulates muscle growth and restores muscle strength and endurance. The present study aimed at investigating whether 15-PGDH inhibition promotes muscle reinnervation and NMJ restoration, thus improving muscle function. Methods and results: We treated young (3-month) and old (27-month) mice with a small molecule compound with high specificity for 15-PGDH inhibition for 30 days. Old treated mice displayed increased muscle mass and strength (p<0.05) compared to aged control mice. While aged control displayed, as expected, a high percentage of denervated NMJ (21.6%), denervation was partially rescued by 15-PGDH inhibition (12.1%, p<0.05). Similarly, NMJ fragmentation was lower in treated versus control mice (18.1% vs 29.3%, p<0.05). To translate our findings to a more acute scenario, we induced nerve-crush injury in young mice (3-month) and treated animals with 15-PGDH inhibition during injury recovery. Treated mice were able to exert a 37.2% higher tetanic force 14 days after injury compared to control mice. This was accompanied by increased muscle mass and specific force (+32.2%, p<0.05) and an increased percentage of innervated NMJs (97.4% versus 84.5%) in treated versus control mice, suggesting that 15-PGDH inhibition was promoting NMJ restoration and muscle reinnervation after injury. Conclusion: In this study we identify 15-PGDH inhibition as a new potential therapeutic strategy to promote reinnervation of NMJs and strength recovery after acute or chronic denervation due to injury or aging.

Funding: E.M. is supported by a “Wu Tsai Human Performance Alliance” fellowship. This study was supported by the Donald E. and Delia B. Baxter Foundation, the Li Ka Shing Foundation, Milky Way Research Foundation MWRF-216064, California Institute for Regenerative Medicine grant DISC2-10604, and U.S. National Institutes of Health (NIH) grants R01-AG020961, R01-AG069858, and R01-RHG009674 to H.M.B.

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.
In vitro examination of the antioxidants, osajin and pomiferin, in cultured rat mesangial cells
Authors: Gnalian Aleena , Carvalho Paulo , Ford Bridget
Published: May 2024

Purpose: The goal of this study was to identify concentrations of osajin and pomiferin, purified compounds originating from Maclura pomifera, that work as effective antioxidants while maintaining cell viability in cultured rat mesangial cells. Rationale and Significance: Diabetic nephropathy (DN) is a serious complication faced by type 1 and type 2 diabetic patients alike. Oxidative stress has emerged as an important pathogenic mechanism in the development of glomerular and tubular injury in DN. Identifying novel antioxidants found in natural compounds could serve as an effective treatment in DN to prevent renal cell damage. Methodology: Rat mesangial cells (NMS) were grown to confluency in RPMI 1640 medium with 17% fetal bovine serum and 1x antibiotic/antimycotic. NMS cells were exposed to vehicle (control) or varying concentrations of pomiferin or osajin. MTT cell survival assays were used to assess cell viability for the selected concentrations. Antioxidant status was assessed using the Total Antioxidant Capacity Assay from Sigma-Aldrich and quercetin was selected as a positive control. Findings: Data from MTT cell viability assays demonstrated several concentrations (25, 50, and 100 mM) of both osajin and pomiferin maintained cell viability in NMS cells. Antioxidant capacity assay plans will be discussed as this is an ongoing project and we hope to identify the total antioxidant capacity and antioxidant response in NMS cells. Future plans also include moving forward with selected concentrations to identify the effectiveness of osajin and/or pomiferin in preventing high glucose-induced damage to glomerular cells and proximal tubular epithelial cells as this will be essential for investigating the benefit of using either compound in diabetic nephropathy.

Research reported in this poster was supported by the University of the Incarnate Word Offce of Research and Graduate Studies.

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.
Measuring fecal neurotransmitter concentrations using Dried Fecal Spot (DFS)-based LC-MS/MS bioanalysis
Authors: Horvath Thomas , Thapa Santosh , Yacyshyn Mary Beth , Yacyshyn Bruce , Engevik Melinda , Chace Donald
Published: May 2024

Background: Guthrie implemented dried blood spot (DBS)-based bioanalytical techniques in the 1960s in order to screen for phenylketonuria (PKU) disease in neonates. Historically, the dominant matrix analyzed using the “Guthrie card” platform has been whole blood, but recent advances in device technology now allow for whole blood-to-plasma sample processing prior to drying and subsequent bioanalysis. This project aimed to use this dried matrix technologies in an entirely new direction by performing dried fecal spot (DFS)-based bioanalysis for analytical microbiology and microbiome applications. Homogenized fecal sample extracts were loaded onto quantitative DBS (qDBS) devices and were allowed to dry overnight, then were shipped at ambient shipping temperature. The DBS spots were processed and subjected to LC-MS/MS-based targeted metabolomics using our Glutamate Cycle method (Glu, Gln, and GABA). Methods & Results: Fecal samples were collected from each of the five human subjects enlisted in the following cohorts: 1) healthy controls; 2) patients with diarrhea; and, 3) Clostridioides diffcile-infected (CDI) patients. A volume of ice-cold methanol:water (1:1, v:v) equivalent to a fecal density of 50 mg/mL was added into individual homogenization tubes that each contained 100 mg of 1.4 mm silica beads. Fecal samples were homogenized using 5 bead-beating cycles (4 m/s for each 20 s pulse). After centrifugation (@500 g), a 20-μL sample supernatant volume was loaded onto qDBS devices that yielded an exact 10-μL DFS spot volume on the embedded cards. Dried DFS spots were removed from the device and homogenized in a 200-μL volume of an IS solution. The Glu, Gln, and GABA concentration of each sample was compared against the concentrations measured in the matched frozen fecal extracts. We were able to successfully detect GABA in both the standard extraction method and in our processed DFS samples. Interestingly, we observed large variability between patient samples and there were no statistically significant differences between the cohorts. Conclusion: Collectively, these data demonstrate the utility of our method for measuring the concentrations of Glu, Gln and GABA contained in our processed DFS-based sample sets.

This study was supported by the NIH K01K123195-01 (MAE). The Texas Children’s Hospital Department of Pathology provides salary support to Texas Children’s Microbiome Center-Metabolomics Lab staff, and purchased all of the reagents, the consumables and durable supplies, and the liquid chromatography-tandem mass spectrometry (LC-MS/MS) equipment described.

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.
Looper, an updated closed loop feature detection platform for automated neonate cardio-respiratory measurements and data analysis
Authors: Ward Christopher , Al-Madi Mahmoud , Lusk Savannah , Patel Dipak , Memos Nicoletta , Ray Russell
Published: May 2024

Facemask pneumotachography is a common, precise experimental approach for measuring respiratory outcomes in neonate rodents (P7-8), particularly in autoresuscitation experiments that inform upon Sudden Infant Death Syndrome where failure of autoresuscitation is hypothesized to be a common endpoint. However, current approaches rely on direct, real-time waveform inspection by an observer and their highly variable reaction times to execute responsive changes in assay gas exposures. Looper, represents a novel and significant improvement on typical observer-based interpretation of live data to initiate challenge and recovery gas applications to uncover nuanced features in neonate cardiorespiratory physiology. Leveraging our previously published Breathe Easy software, we have expanded the analytical capabilities of the software to analyze key features within a typical autoresuscitation cycle. Utilizing the software output, we have further developed machine learning approaches that enable real-time prediction of cardio-respiratory failure based distinct waveform features more than 10min in advance, setting the stage for novel experiments to identify critical interventional windows for enhancing resuscitation.

R01HL161142 R01HL130249.

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.
DerP1, a house dust mite protease, directly activates airway vagal afferents and induces airway hyperreactivity after chronic exposure
Authors: Patil Mayur , lurye Karina , Sargeant Marisa , Hadley Stephen , Taylor-clark Thomas , Akopian Armen
Published: May 2024

Airway hyperreactivity (AHR) is one of the main symptoms of allergic asthma. Current therapeutics used in the treatment of allergic asthma do not target the AHR. Airway sensory afferents have been shown to be critical in AHR, but the mechanisms remain elusive. We have previously shown that house dust mite (HDM) extract, which contains multiple different proteases, can directly activate these airway sensory afferents in the lung via PAR1 receptors. In this study we identified the most potent protease DerP1 is capable of directly and robustly activating airway sensory vagal afferents. DerP1 caused a significant release of CGRP, a neuropeptide released after nerve terminal activation, from the airways. We observed that DerP1 caused a calcium influx in 65% of TRPV1 positive lung specific neurons. We also observed that in our two-photon ex vivo imaging of the vagal ganglia of PirtCre;R26 ‐ GCaMP6s mice, DerP1 caused a robust activation of approximately 60% of naïve airway-specific C-fibers. Calcium imaging of the lung specific vagal neurons from wild type, TRPA1 KO and TRPV1 KO revealed that the DerP1 mediated activation was absent in TRPV1 KO mice neurons. We then found that mice exposed to DerP1 chronically over a period of 12 days (without an adjuvant) had significant AHR and Th2 mediated airway inflammation. Our data suggests that direct activation of airway vagal C-fiber afferents by DerP1 via TRPV1 chronically leads to airway hyperreactivity and Th2 mediated airway inflammation.

Warren Alpert Foundation.

This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.