bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pathophysiology of Carnitine Palmitoyltransferase 2 (CPT2) Deficiency in the Dahl Salt-sensitive R at
Authors: Smith Brody , Dissanayake Lashodya , Zietara Adrian , Levchenko Vladislav , Upadhyay Gunjan , Palygin Oleg , Halade Ganesh 
Published: May 2024

Carnitine palmitoyltransferase 2 (CPT2) is an essential enzyme of the carnitine shuttle, which facilitates fatty acid -oxidation in mitochondria. This study aims to characterize the various effects of CPT2 deficiency on the Dahl salt-sensitive (SS) rat metabolome and its concomitant influence on renal homeostasis. CRISPR/Cas9 was used to insert a single base pair into the SS Cpt2 gene, causing a frameshift mutation found to be lethal in homozygotes (SSCpt2−/−). Western blotting and qPCR analysis of renal cortex tissue confirmed a reduced expression of CPT2 in heterozygous (SSCpt2+/-) rats compared to wild-type (WT) littermates; therefore, male and female heterozygotes were used for all experiments. Lipid metabolomics of renal cortex samples collected from SSCpt2+/- animals at 8 weeks old on a baseline 0.4% NaCl diet revealed a significant upregulation in inflammatory lipids such as 11-HETE (p<0.01) and 12-HHT (p<0.05) when compared to WT littermates. Urine analysis from the SSCpt2+/- group demonstrated a severe reduction in acetoacetic acid production (p<0.001), indicating ketogenesis is likely impacted by the loss of CPT2 in -oxidation. Additionally, TCA cycle metabolites fumaric acid (p<0.05) and oxaloacetic acid (p<0.01) are significantly downregulated in urine from SSCpt2+/- animals. Radio telemeters were implanted into the rats at 8 weeks of age to continuously record mean arterial pressure (MAP) and monitor the development of SS hypertension over the course of several dietary treatment protocols. Three weeks of either a 4% NaCl high-salt (HS) diet or a HS + ketogenic (HSK) diet with equivalent caloric content (4:1 caloric ratio, fat: carbohydrate) were administered to the animals. No difference in MAP elevation occurred between groups after the HS challenge alone, but SSCpt2+/- animals on the HSK diet had a significantly attenuated development of hypertension (p=0.03). Further metabolic analysis after the HSK diet illustrated that both groups had similar increases in long-chain fatty acids, liver enzymes, and cholesterol levels with a decrease in short-chain fatty acids. These experiments show that the partial loss of CPT2 in the Dahl SS rat leads to dysregulation across multiple metabolic pathways. Moreover, a ketogenic diet appears to protect heterozygous animals from the development of salt-sensitive hypertension. Funding: NIH R35 HL135749 and VA I01 BX004024. 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.
Obesity to Type 2 Diabetes Mellitus: Importance of Longitudinal Characterization of the Progressive Phases as Identified in Rhesus Monkeys Maintained Under Constant Diet and Environmental Conditions
Authors: Hansen Barbara , Pattnaik Aishaya , Alvoir Joshua , Volante Vernon 
Published: May 2024

The complex physiological mechanisms that underlie the links between obesity and T2DM involve “adiposity-induced” alterations in beta cell function —not yet mechanistically understood. Clearly the changes in beta cell function are greatly increased during the progression of obesity, --not reduced!! AND multiorgan insulin resistance whose mechanisms are unknown (although likely reduced by weight loss). Rhesus monkeys have shown these and have provided an amazing look at the Phases that lead to T2DM. We have previously summarized, in a table of 49 variables, the many ways that the nonhuman primate rhesus monkey offers exciting opportunities for insight into these extraordinary conditions compared to the human with T2DM. The Importance of longitudinal characterization, with a number of measurements that are regularly and periodically carried out to assess longitudinally some of the pathophysiological processes that develop spontaneously and naturally in these monkeys as they progress from normal, lean, young animals to obese animals with or without various physiological disturbances undergo the aging process. Usually these disturbances develop at varying rates in different monkeys and include hypertension, hyperlipidemia, hyperinsulinemia, hyperglycemia, impaired glucose tolerance, insulin resistance, peripheral neuropathy, impaired renal clearance, and cardiovascular disease—in short, the entire syndrome that becomes manifest in aged and diabetic humans. The longitudinal studies depend specifically on regular assessment of each animal and determination of the rate at which that animal is or is not progressing in the development of pathophysiological disturbances. Identification of phases allows one to estimate where a given monkey is in regard to the progression to overt diabetes. Application to humans will greatly increase our predictive ability to understand the mechanisms underlying both obesity and T2DM. NIA NO1AG3 1012. 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.
No relation between increases of spleen volume and reductions in circulating pro-inflammatory microparticles following fourteen days of apnea and hypoxia exposures
Authors: Keeler Jason , Hite M. Jo , Hess Hayden , Tourula Erica , Chapman Robert , Johnson Blair , Ilardo Melissa 
Published: May 2024

INTRODUCTION: Indigenous breath-hold diving populations have comparatively large spleen volumes, suggesting a functional benefit of a larger spleen in the context of diving. The spleen plays a role in clearing blood-borne microparticles (MPs). Pro-inflammatory MPs are increased with diving and have been associated with the etiology of decompression sickness. Thus, a potential benefit of a larger spleen may be enhanced splenic clearance of MPs. Repeated apneas and hypoxia exposure increases spleen volume in people without breath-hold diving ancestry. PURPOSE: Test the hypothesis that repeated apnea and hypoxia exposures reduce blood-borne pro-inflammatory MPs and the reduction is correlated with changes in spleen size. Methods: 20 healthy adults (10 women) completed 10 maximal apneas and 3 h of exposure to normobaric hypoxia (FiO2=0.14) for 14 days within a 16-day period. On Days 1 and 14, pre-exposure spleen volume was measured via ultrasound using the Pilström equation and venous blood was collected for blood-borne pro-inflammatory MPs analysis via flow cytometry. MPs data were log transformed for analyses. Data are presented as mean ± SD. Results: Average apnea duration increased from Day 1 (76±31 s) to Day 14 (91±30 s, p=0.004, dz=0.48). Pre-exposure spleen volume increased from Day 1 (169±36 ml) to Day 14 (182±39 ml, p=0.002, dz=0.33). Total MPs decreased from Day 1 (1407±814 #/μl) to Day 14 (1092±561#/μl, p=0.047, dz=0.45). MPs expressing CD66b+ (neutrophil origin; 194±89 vs. 156±72 #/μl, p=0.014, dz=0.47) and CD146 (endothelial origin; 337±197 vs. 250±116 #/μl, p=0.037, dz=0.53) were lower on Day 14, but MPs expressing CD41a (platelet origin) did not differ between Days 1 (82±78 #/μl) and 14 (55±38 #/μl, p=0.166, dz=0.45). Changes in MP counts from Day 1 to Day 14 were not correlated with changes in spleen volume for Total MPs (r=0.02, p=0.93) nor MPs expressing CD66b+ (r=0.30, p=0.23), CD146 (r=-0.04, p=0.86), or CD41a (r=0.31, p=0.20). CONCLUSION: Repeated apnea and hypoxia exposures increase spleen volume and reduce blood-borne pro-inflammatory MPs. However, there was no relation between exposure-induced changes in spleen size and MP counts. Thus, spleen size may not directly impact MP clearance. Rather, alterations in the MP phagocytic properties found within the spleen or another systemic change likely contribute to the observed reductions in MPs. Further work is needed to understand the role of splenic function in these observations. Support: Offce of Naval Research (N00014-20-1-2593). 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.
Strategies for Inducing and Validating Zinc Deficiency and Zinc Repletion
Authors: Wenegieme Tara-Yesomi , McMichael Kelia , Elased Dalia , Hasrat Khanzada , Rockwood Jananie , Ume Adaku , Marshall Andrea 
Published: May 2024

Background: According to the World Health Organization, zinc deficiency is a growing global health problem, impacting 31% of the world’s population. Zinc deficiency is a common comorbidity with many chronic diseases, from skin to kidney diseases. Given the increasing interest in zinc’s role in disease onset and progression, there is a dire need for reproducible approaches to manipulate zinc homeostasis. Here, we provide proven strategies for inducing and validating zinc deficiency and zinc repletion in a mouse model. Experimental Design: After acclimating to a ZnA (zinc adequate) diet, mice are randomly assigned to either a ZnA or ZnD (zinc deficient) diet. To replete zinc levels (ZnR), a subset of ZnD mice is returned to the ZnA diet. Animal growth rates and plasma zinc levels are assessed to validate zinc status. Results: Mice placed on the ZnD-diet have reduced body weights (26.48g ± 0.78) compared to mice maintained on the ZnA-diet (28.12g ± 0.13). However, zinc repletion promotes weight gain (27.87g ± 1.01) resulting in body weights comparable to mice maintained on the ZnA-diet. Furthermore, mice maintained on the ZnA-diet have plasma zinc levels of 3.19 μM/g Body Weight. While plasma zinc levels are 40% lower in mice place on the ZnD-diet (1.29 μM/g Body Weight). In contrast, plasma zinc levels (2.44 μM/g Body Weight) are increased in ZnR mice. Conclusion: These findings validate that the described dietary approach is an effective strategy for inducing zinc deficiency and zinc repletion. Significance: This cost-effcient approach will enhance the scientific rigor and reproducibility of studies examining the impact of zinc deficiency, and repletion on disease onset and progression. Funding Source: R21 DK119879, R01 DK-133698. 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.
Chemogenetic phrenic motoneuron activation enables increased tidal volume
Authors: Benevides Ethan , Thakre Prajwal , Rana Sabhya , Oweiss Karim , Polotsky Vsevolod , Fuller David 
Published: May 2024

Reduced output of the phrenic neuromuscular system and the resultant respiratory insuffciency occurs in many neuromuscular disorders. We hypothesized that expressing an excitatory DREADD (designer receptors exclusively activated by designer drugs) in phrenic motoneurons would enable DREADD-ligand induced increases in inspiratory tidal volume in awake, freely behaving rats. ChAT-Cre rats (n= 9; female n= 3) underwent bilateral injections of a Cre-dependent viral construct, AAV9-hSyn-DIO-hM3D(Gq)-mCherry (titer: 2.07x1012 vg/mL) into the mid-cervical (C4) ventral horn (1 μl injected per side). The combination of focal AAV injection and Cre-dependent expression was expected to drive hM3D(Gq) expression primarily in phrenic motoneurons, which are ChAT-positive and located in the C3-C5 ventral horn. Whole-body plethysmography was used to measure breathing frequency, tidal volume, and minute ventilation before and after intravenous delivery of a DREADD ligand, JHU37160 (J60), or saline (sham). Delivery of the ligand produced an increase in inspiratory tidal volume compared to saline infusion (two-way RM ANOVA, p= 0.037). Respiratory rate was similar between the two conditions (p= 0.582). Two weeks after plethysmography recordings, rats were urethane anesthetized and phrenic nerve electrical activity was directly recorded using suction electrodes. This procedure was done to directly assess the impact of intravenous delivery of the DREADD ligand on phrenic motoneuron output. The J60 ligand caused a rapid, sustained, and bilateral increase in phrenic nerve efferent burst amplitude (one-way RM ANOVA, p< 0.001), whereas saline injection had no impact. The increase in phrenic burst amplitude lasted up to 100 minutes, at which point the experiment was stopped. We conclude that expression of an excitatory DREADD in phrenic motoneurons enables DREADD ligand induced increases in tidal volume in the awake, unrestrained rat. The phrenic nerve recordings verify that this response very likely reflects activation of phrenic motoneurons. Funding: R01HD052682-14 (DDF), R01HL153140-04 (DDF), University of Florida Graduate Fellowship (ESB). 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.
Comprehensive Assessment of the Impact of Alcohol Use on Cognitive Deficits in People with HIV
Authors: Fitzpatrick-Schmidt Taylor , Oral Evrim , Welsh David , Molina Patricia , Ferguson Tekeda , Edwards Scott 
Published: May 2024

Human immunodeficiency virus (HIV) infection profoundly impacts the nervous system, leading to neurological deficits such as HIV-associated neurocognitive disorder (HAND). HAND represents the most common neurological comorbidity among people with HIV (PWH), and alcohol use may exacerbate the cognitive deficits seen in this condition, especially in underserved populations. This study aimed to investigate the relationship between alcohol use patterns and cognitive performance in an underserved cohort of PWH, with the hypothesis that alcohol misuse would exacerbate cognitive deficits in this population. Data collected from participants (n=259; 66.7% male; mean age 52 ± 10 years) enrolled in the New Orleans Alcohol Use in HIV (NOAH) study were utilized for cross-sectional analysis. Cognitive function was assessed using the Montreal Cognitive Assessment (MoCA), and alcohol use was comprehensively measured by four metrics: Alcohol Use Disorders Identification Test (AUDIT), 30-day timeline followback (TLFB), lifetime drinking history, and phosphatidylethanol (PEth) levels. The average MoCA score among participants was 20.7 ± 4.5, with 86.5% demonstrating cognitive impairment (MoCA < 26). Notably, individuals with total MoCA scores below 18 (classified as moderately or severely cognitively impaired) had a higher frequency of recent severe alcohol misuse (as assessed by PEth levels) and greater lifetime alcohol consumption. Participants at increased risk for AUD (as assessed by the AUDIT) also had worse global cognition and memory task performance, particularly those aged 50 and older. Further analysis of MoCA sub-score data indicated that participants with increased AUD risk had significant impairments in the cognitive domains of language, delayed recall, and memory. These findings highlight the importance of considering alcohol use and AUD risk as important factors that may exacerbate cognitive decline in vulnerable populations, including older patients and PWH. Future analyses will compare the relationship between cognition and alcohol in these HIV-positive patients with a cohort of HIV-negative patients to better understand the impact of concurrent HIV and alcohol misuse on cognitive function. This research was supported by grant #F30AA030941, #T32AA007577, and #P60AA009803 from the NIAAA at 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.
Characterizing MetALD in a Nonhuman Primate Model using High Fat and Sucrose Diet and Chronic Binge Alcohol Administration
Authors: Gallegos Eden , Simon Liz , Molina Patricia 
Published: May 2024

Mechanisms leading to metabolic and alcohol associated liver disease (MetALD) are not clearly delineated. This study examined the differential regulation of markers of hepatic mitochondrial function in nonhuman primates fed a high fat/high sucrose (HFSD) and administered chronic binge alcohol (CBA) or vehicle as compared to control-fed animals. We hypothesized that markers of hepatic dysregulation due to HFSD will be further altered by the combination of CBA/HFSD. Eight rhesus macaques were fed HFSD (27% sucrose and 42% fat, by kcal) with n=4 receiving vehicle and n=4 receiving 13-14g/kg/wk of ethanol through a gastric catheter. Rhesus macaques fed standard primate chow were used as reference controls (n=4-6). Liver RNA was isolated for determining expression of genes regulating mitochondrial biogenesis and function using RT-qPCR. Results were analyzed using one-way ANOVA and post-hoc pairwise multiple comparisons were performed using Tukey’s method, with alpha set to 0.05. Expression of inflammatory genes was significantly altered across the groups (p<0.05). HFSD increased tumor necrosis factor alpha (p=0.01), interleukin 1-beta (p=0.04), cluster of differentiation 38 (p=0.01), and transforming growth factor beta (p=0.01) expression compared to control. Both HFSD and CBA/HFSD increased interleukin-10 compared to control (p=0.02, p=0.03). Gene expression of mitochondrial function and oxidative stress regulators were significantly altered across the groups (p<0.05). CBA/HFSD decreased expression of peroxisome proliferator-activated receptor-gamma coactivator-1 beta (p=0.04) and nuclear respiratory factor 2 (p=0.04) compared to control. Both HFSD and CBA/HFSD decreased peroxisome proliferator-activated receptor alpha expression compared to control (p=0.01, 0.01). HFSD decreased superoxide dismutase 2 (SOD2) expression compared to control (p=0.01) and increased uncoupling protein 2 (p=0.01). SOD2 expression was increased only in CBA/HFSD compared to HFSD (p=0.01). These results reveal marked HFSD-mediated increases in markers of inflammation and CBA/HFSD-mediated changes in markers of mitochondrial function regulation and oxidative stress regulation. These findings suggest a greater impact of calorie-dense diets than CBA on hepatic inflammation and a combined impact of CBA and HFSD on mitochondrial regulation. Ongoing studies will examine oxidative phosphorylation complex protein activities and expression to elucidate and integrate HFSD or CBA mediated changes in hepatic bioenergetic capacity. Supported by F30AA030910, P60AA009803, and T32AA007577. 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.
Empagliflozin, an SGLT2i, relaxes coronary smooth muscle at pharmacological concentrations
Authors: Essajee Sal , Warne Cooper , Tucker Selina , Tune Johnathan , Dick Gregory 
Published: May 2024

Morbidity and mortality due to heart failure with preserved ejection fraction (HFpEF) is increasing and there are no universally recognized strategies for treatment. Sodium-glucose co-transporter type 2 inhibitors (SGLT2i), such as Empagliflozin, have been shown to reduce myocardial stiffness and improve coronary microvascular performance, but mechanisms are unclear. Previous studies in rabbit aorta and rat mesentery suggest Empagliflozin relaxes smooth muscle through activation of K+ channels. This study investigated the effects of therapeutic and pharmacological concentrations of Empagliflozin (10-300 μM) on the isometric tension of left circumflex (CFX) coronary arteries from Yorkshire swine. We tested the hypothesis that Empagliflozin would relax coronary smooth muscle via a concentration-dependent manner, involving K+ channels. CFX arteries were dissected, cleaned of adventitia, cut into 3 mm rings (n = 16), and mounted in organ baths containing Krebs-Henseleit buffer (37 °C) for isometric tension studies. Each CFX segment was adjusted to optimal preload (~3 g passive tension) as determined by <10 % change in active tension in response to 60 mM KCl. In order to determine whether Empagliflozin caused relaxation and, if so, by what mechanism, rings were contracted with either 30 mM K+ or the thromboxane mimetic U46619 (1 μM). Once tension plateaued, Empagliflozin (10-300 μM) was added in increasing concentrations. Therapeutic concentrations of Empagliflozin (10-30 μM), elicited no significant relaxation. Pharmacologic concentrations of Empagliflozin (≥100 μM) caused significant relaxation from ~15 ± 11% to ~45 ± 10% in response to 100 μM vs. 300 μM Empagliflozin, respectively. Relaxation was not different between rings contracted with K+ or U46619, suggesting membrane hyperpolarization via K+ channels is not involved. Our results represent the first study of the effects of Empagliflozin on coronary smooth muscle reactivity. Data support the idea that relaxation of coronary smooth muscle by Empagliflozin occurs at supra-pharmacologic concentrations in vitro, but K+ channel activation appears to be an unlikely mechanism. This project was supported by National Institutes of Health grant R01 HL158723. 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.