bluuebunny/crossref_metadata_2025_split huggingface dataset:
Micro-RNA-532-3p: a potential target in CKD-HFpEF pathophysiology
Authors: Chade Alejandro , Eirin Alfonso 
Published: May 2023

Background: Chronic kidney disease (CKD), an independent risk factor for heart failure with preserved ejection fraction (HFpEF), is present in over 50% of CKD patients and accounts for over 50% of hospital admissions for HF. We showed in a novel swine model of CKD-HFpEF that cardiac abnormalities associate with upregulation of pro-inflammatory nuclear factor kappa B (NF-kB). NF-κB activation is controlled by its natural inhibitor IkBα, a protein encoded by the NFKBIA gene that prevents its nuclear translocation, but the exact mechanisms remain unknown. We hypothesize that micro-RNAs (miRNAs), small noncoding RNAs that regulate gene expression, downregulate cardiac NFKBIA and activates NF-κB contributing to cardiomyocyte injury in CKD-HFpEF. Methods: Unbiased cardiac miRNA-sequencing was performed in normal and CKD-HFpEF pigs (n=4/group, 2 males/2 females). Differentially expressed (fold change ≥2 and false discovery rate (FDR)≤0.05) miRNAs capable of targeting NFKBIA were identified using miRWalk 3.0 and Target Scan 8.0, further validated by qPCR. To study the impact of CKD-HFpEF on cardiac tissue, cardiomyocites (CM) were exposed for 48 hours to plasma from normal and CKD-HFpEF pigs (n=3 each) and cardiac injury (LDH release) evaluated, and selected miRNAs modulated (mimic, antagomiR). Results: All CKD-HFpEF pigs showed a significant reduction in renal hemodynamics and function compared to controls accompannied by left ventricular hypertrophy (LVH), abnormal diastolic relaxation and LV strain, and increased circulating ANP and BNP levels, underscoring successful developing of CKD-HFpEF.Unbiased miRNA-seq identified 402 miRNAs targeting NFKBIA, of which 13 were broadly conserved among vertebrates and only 4 expressed in pig’s cardiac tissue. Among them, only miR-532-3p was upregulated in myocardium of CKD-HFpEF pigs.Expression of miR-532-3p was also higher in CM exposed to CKD-LVDD plasma or miR-532-3p mimic, associated with down-regulation of NFKBIA and LDH release. Treatment with anti-miR-532-3p decreased miR-532-3p, increased NFKBIA expression, and reduced CM injury. Conclusions: These observations support a role of miR-532-3p in cardiac NF-kB activation in CKD-HFpEF. In turn, these proof-of-concept studies may assist to identify novel therapeutic targets and develop new interventions to protect the heart in CKD. NIH HL095638 (ARC), DK129240 (AE) This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.
Metacognitive training did not increase retention of content in upper-division Anatomy and Physiology course
Authors: Schaefer Jennifer , Odegard Jack 
Published: May 2023

Metacognitive training was embedded into an upper-division Human Anatomy and Physiology course to examine whether training improved student metacognition and retention of course content. Training included explicit instruction on the definition and value of metacognition, practice in course-specific metacognitive strategies, and assignments in which students reflected on their metacognitive strategies and how their metacognitive strategies could be altered to improve learning and exam grades. Previous work indicated that metacognitive training improved self-reported metacognitive practices and protected against declines in student self-efficacy, but did not improve exam scores. Therefore, we wondered whether the benefit of metacognitive improvement was in content retention rather than improved exam scores. This study hypothesized that metacognitive training, and the subsequent gains in self-reported metacognitive practices, would improve student retention of course content one month after the end of the course. Results indicate that students who received metacognitive training improved self-reported metacognitive practices while student who did not receive training did not improve metacognitive practices. However, metacognitive training did not alter the level of course content retained one month after the end of the course. This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.
Acute effects of fentanyl on carotid body sensory activity
Authors: Garcia Ethan , Srinivasan Dhivya , Chang Andy 
Published: May 2023

Opioid drugs have long served as important agents for pain management in the clinic, but misuse of opioids, especially of illicit ultra-potent synthetic opioids like fentanyl, is driving the growing opioid epidemic. Like the natural opioid morphine, fentanyl targets μ-opioid receptor signaling in the central nervous system. However, the pharmacology of fentanyl on the opioid receptors differs from morphine, and clinical symptoms of fentanyl overdose like opioid-induced respiratory depression (OIRD) are more severe and less well-managed by reversal agents like naloxone. Hypoventilation due to OIRD stimulate peripheral chemoreceptors like the carotid body (CB). Previous reports suggest that morphine has minor effects on CB sensory output or the hypoxic ventilatory response mediated by the CB in animal models. Denervation of the CB significantly attenuates the hypoxic ventilatory response of unaesthetized rats after morphine treatment, suggesting that CB sensory activity persists in the presence of morphine to defend against OIRD. However, the effect of fentanyl on CB sensory responses has been little explored. Our goal was to determine how fentanyl regulates CB activity at the level of glomus cells, neuroendocrine sensory cells in the CB that signal to afferent nerves that project to the brainstem to increase ventilation. Sensory stimuli like hypoxia induce calcium transients in glomus cells across all species studied, including human. By two-photon imaging, we performed calcium imaging of mouse glomus cells expressing the genetically encoded calcium indicator GCaMP3 in intact CBs. Whereas morphine suppresses the activity of neurons in the central nervous system, application of fentanyl at levels sufficient to induce OIRD in mice acutely increased calcium transients in CB glomus cells. This increase in intracellular calcium was suppressed by naloxone, indicating that the stimulatory effect of fentanyl was mediated through opioid receptor signaling. In addition, we tested if glomus cells could respond to sensory stimuli in the presence of fentanyl. We found that the combination of fentanyl and hypoxia (PO2~25 mmHg) increased calcium responses over either fentanyl or hypoxia alone. These results suggest that CB stimulation through sensory pathways could potentially be targeted to increase ventilation in OIRD. Experimental groups contained 22-73 cells from least two preparations from different animals, and p<0.05 was set as a significant difference using appropriate statistical test. This work is funded by a UCSF Innovation Ventures Catalyst Grant and NIH Grant R41DA056270. AJC is a co-founder of Olfa Thera, Inc. This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.
Expansion microscopy and biorthogonal labeling with non-canonical amino acids enables cluster analysis of Na, K-ATPase in the plasma membrane
Authors: Edwards Steven , Bauer Sebastian , Graef Philipp , Meineke Birthe , Elsässer Simon , Brismar Hjalmar 
Published: May 2023

Recent developments in expansion microscopy and techniques for site-specific fluorescent labeling of proteins opens new possibilities to study nano-scale protein distributions. We have studied the spatial distribution of Na, K-ATPase alpha and beta subunits in the plasma membrane of epithelial cells. For this we developed sample preparation protocols based on genetic code expansion, click chemistry and expansion microscopy. We transiently transfected HEK 293T cells with constructs containing the coding sequence for the Na, K-ATPase subunits (alpha1 and beta1) carrying a premature amber or ochre stop codon. Two bioorthogonal tRNA and tRNA synthetase pairs were also transfected for stop codon suppression and site-specific insertion of two unnatural amino acids, ProK and TCO*K. The unnatural amino acids were then labelled with small organic dyes using CuAAC and SPIEDAC click reactions.The dyes AF488 picolyl azide and Abberior STAR 635 tetrazine were used to label the two subunits on living cells. Expansion microscopy was performed using a modified MAP protocol, reaching an isotropic expansion of approximately 4.5-fold. Confocal airyscan microscopy of the expanded cells with <50nm resolution revealed nanoscale variations in Na, K-ATPase density and enabled detailed analysis of the proteins distribution. We propose that the spatial distribution of Na, K-ATPase in the plasma membrane has a regulatory function for the local ion pumping efficiency in the cell. VR 2020-05347, VR 2019-00217 (Swedish Research Council) This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.
The role of T-type channels in the differential response to oxytocin of virgin and proven breeder rats uteri
Authors: Porta Maura , Boyman Elisabeth , Sondgeroth Korie 
Published: May 2023

Introduction: It is commonly known that an increase in parity is associated with faster labor times, increased risk of hemorrhage, and greater chance of spontaneous delivery (1). The mechanisms of these differences have not yet been fully elucidated. Earlier research conducted in the lab demonstrated that pregnancy alters the response of uterine muscles to oxytocin. Hypothesis: We hypothesized that the intracellular calcium handling machinery, particularly T-type calcium channels, contributes to the differential response to oxytocin in the myometrium from virgin (V) and proven breeder (PB) rats. Methods: Virgin (V) and proven breeder (PB) NP female 18-week-old rats were staged and euthanized at proestrus. One uterine horn was dissected in strips suspended in a tissue bath containing Krebs solution (in mM, NaCl 117, KCl 4.7, NaHCO3 25, MgCl2 1.2, KH2PO4 1.2, CaCl2 2.5, glucose 11, pH= 7.4) at 37°C and bubbled with 95% O2 and 5% CO2. Dose response curves to oxytocin (10E-10 to 10E-5 M) were recorded in the presence of the T-type calcium channels inhibitor Mibefradil. Contractility was evaluated as the area under the curve of recorded contractions. The other uterine horn was flash frozen in liquid NO2 and later used for qRT-PCR experiments. T-tests and ANOVA two ways were used for statistical analysis. Results: Mibefradil significantly reduced the spontaneous contractility of the sample and the response to oxytocin (P<0.001). The maximal contractility in the two groups was similar, whereas in the experiments without the drug PB max contractility was higher. However, the range of activation (Max-Min) was higher for PB samples, as previously observed in the absence of the drug. RT-PCR revealed a two-fold increase in T-type channel receptors on the PB uterus compared to the V. Conclusions: Although T-type channels are slightly more expressed in PB than in V uterine tissue, their impact on the differential response to Oxytocin mechanism is limited. Thus, L-type Calcium channels seem to play a more important role in this mechanism. This study was supported by a Kenneth Suarez Fellowship to EB and an MWU intramural fund to MP This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.
The pedunculopontine tegmental nucleus is not important for breathing impairments observed in a Parkinson's disease model
Authors: Miranda Nicole , Oliveira Luiz , Aquino Yasmin , Moreira Thiago , Takura Ana Carolina 
Published: May 2023

Parkinson's disease (PD) is a motor disorder resulting from degeneration of dopaminergic neurons of substantia nigra pars compacta (SNpc), with classical and non-classical symptoms such as respiratory instability. An important region for breathing control, the Pedunculopontine Tegmental Nucleus (PPTg), is composed of cholinergic, glutamatergic, and GABAergic neurons. Our main hypothesis is that degenerated PPTg neurons contribute to the blunted respiratory activity in a PD model. Adult mice (males and females) (CEUA: 6641200919) that express the fluorescent green protein in cholinergic, glutamatergic or GABAergic cells were used (Chat-cre Ai6, Vglut2-cre Ai6 and Vgat-cre Ai6) and received bilateral intrastriatal injections of vehicle or 6-hydroxydopamine (6-OHDA, 10 μg/μl). Ten days later, the animals were exposed to hypercapnia (7% CO2) or hypoxia (8% O2) to activate PPTg neurons. Vglut2-cre Ai6 animals also received retrograde tracer injections (cholera toxin b) into the retrotrapezoid nucleus (RTN) or preBötzinger Complex (preBötC) and anterograde tracer injections (AAV-mCherry) into the SNpc. In 6-OHDA-injected mice, there is 79% of reduction in the number of dopaminergic neurons in SNpc (95.09 ± 4.77 vs. vehicle: 456.6 ± 6 neurons) without changing the number of glutamatergic, GABAergic and cholinergic neurons in the PPTg. Hypercapnia activated fewer Vglut2 neurons in6-OHDA animals (8.6 ± 2.7 vs. vehicle 19.5 ± 2.9 neurons), and hypoxia did not activate PPTg neurons. PPTg neurons do not input RTN or preBötC regions but receive projections from SNpc. Although our results did not show a reduction in the number of glutamatergic neurons in PPTg, we observed a reduction in the number of neurons activated by hypercapnia in the PD animal model, suggesting that PPTg may participate in the hypercapnia ventilatory response. Funding: FAPESP, CAPES and CNPq This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.
Palmitic acid induces Oxidative Stress, Senescence and Downregulates Glutamate Transporter Expression in Human Brainstem Astrocytes
Authors: Sivasubramanian Mahesh Kumar , Monteiro Raisa , Balasubramanian Priya , Subramanian Madhan 
Published: May 2023

Glial cells have emerged as critical players in sympathoexcitation and neurogenic hypertension in recent years. Glutamate reuptake transporters display a high vulnerability to oxidative stress resulting in reduced uptake function. We have previously shown that obesity increases superoxide production and 3-nitro-tyrosine levels in the RVLM, suggesting that obesity-induced reduction in EAAT2 expression and activity might be mediated through oxidative stress. Our preliminary studies in human primary brainstem astrocytes (HBAs) also suggest that oxidative stress negatively impacts EAAT2 expression. However, what obesity-related factors induce oxidative stress in the brainstem of obese animals is not clear. In this study, we will test the role of palmitic acid on oxidative stress and astrocytic function in the brainstem. Cultured human brainstem astrocytes were treated with palmitic acid at the dose rate of 25μM for 24 hours. After the treatment period, the cells were collected and processed for real-time PCR analysis. Data was analyzed by unpaired student's t-test and a p-value less than 0.05 was considered statistically significant. Major findings from this study includes a) Palmitic acid mimicked obesity and increased lipid accumulation in brainstem astrocytes marked by significant increase in the expression lipid-droplet associated proteins, perilipin (PLIN) 1 and 2 b) We also found that the oxidative stress markers, NQO1, SOD2, and catalase were significantly higher in treatment group indicating that palmitic acid induced oxidative stress in brainstem astrocytes. c) Gene expression analysis of senescent markers revealed p21 and p53 were significantly upregulated in the treatment group. In addition, Lamin B1, a component of the nuclear envelope was significantly downregulated in the treatment group consistent with the senescence. d) Then we also observed increased gene expression levels of the senescence-associated secretory phenotype (SASP) factors, IL1α, TNFα, IL6, MCP1, and CXCL10, indicative of oxidative stress-induced senescence in brainstem astrocytes treated with palmitic acid. e) More importantly, the levels of glutamate reuptake transporters, EAAT1 and EAAT2 were significantly downregulated in the senescent brainstem astrocytes. Taken together all these results suggest that the palmitic acid induces oxidative stress, senescence and inflammation in the human brainstem astrocytes that could mediate sympathoexcitation through enhanced glutamate neurotransmission in the brainstem in obesity. National Heart, Blood and Lung Institute grant R15HL148844; American Heart Association Institutional Research Enhancement Award - 959725 This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.
The relationship between VO2 max and MSNA in healthy young adults
Authors: Baron John , Loggie Nicole , Corkery Adam , Howery Anna , Miller Kathleen , Eldridge Marlowe , Barnes Jill 
Published: May 2023

BACKGROUND: Muscle sympathetic nerve activity (MSNA) has been shown to be a predictor of cardiovascular diseases. There are currently disputed findings regarding the effects of exercise training on MSNA at rest. Therefore, this study sought to compare MSNA in young exercise trained and sedentary adults. The purpose of this analysis was to examine associations between MSNA at baseline with VO2max in order to determine if VO2max can be a predictor of MSNA. METHODS: Forty-two young adults were evaluated including 11 resistance trained (RE: age = 24 ± 4 years; BMI = 24 ± 2 kg/m2), 18 aerobically trained (AE: age = 27 ± 5 years; BMI = 24 ± 2 kg/m2), and 13 sedentary controls (CON: age = 28 ± 5 years; BMI = 25 ± 2 kg/m2). Participants underwent a maximal exercise test to exhaustion on a cycle ergometer to measure VO2max. During a separate visit, mean arterial pressure (MAP), heart rate (HR) and MSNA were measured at rest for five minutes. MSNA was assessed using burst frequency, burst incidence, and total activity. One-way ANOVA was performed in order to assess between-group differences in MSNA. Simple linear regression was performed in order to determine the impact of VO2max on MSNA and the relationship between MAP and VO2max. RESULTS: There were significant differences in VO2max across all three groups (RE: 41.4 ± 4.6 ml/kg/min; AE: 46.2 ± 4 ml/kg/min; CON: 35.3 ± 6.7 ml/kg/min; p < 0.01) and between groups (RE vs. AE p < 0.01; RE vs. CON p < 0.02; AE vs. CON p < 0.01). There were no differences in MSNA burst frequency (RE: 15 ± 8 bursts/min; AE: 17 ± 7 bursts/min; CON: 18 ± 5 bursts/min; p = 0.57), MSNA burst incidence (RE: 36 ± 13 bursts/100 cardiac cycles; AE: 34 ± 15 bursts/cardiac cycles; CON: 30 ± 7 bursts/100 cardiac cycles; p = 0.27), and total MSNA (RE: 881 ± 684 B/min; AE: 1361 ± 1092 B/min; CON: 1031 ± 379 B/min; p = 0.29) across the three groups. There were no relationships found between VO2max and MSNA burst frequency (r = 0.23; p = 0.15), VO2max and MSNA incidence (r = 0.06; p = 0.71), or VO2max and total MSNA (r = 0.03; p = 0.89). CONCLUSION: In conclusion, these results demonstrate a disassociation between MSNA and VO2max at rest in young adults. Since this analysis was limited to resting values, future studies could examine the relationship between VO2max and MSNA as a result of an exercise training intervention. Funding: NIH HL118154, Virginia Horne Henry This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.
Regulation of hyaluronic acid synthesis and breakdown can prevent significant damage of the lung epithelium in response to SARS-CoV-2 infection
Authors: Harriott Noa , Calvert Ben , Quiroz Erik , Ryan Amy 
Published: May 2023

COVID-19 remains an ongoing global pandemic causing significant respiratory distress and endothelial dysfunction in individuals susceptible to severe disease. Increased production of hyaluronic acid has been observed in patients with severe COVID-19, however its significance in COVID-19 pathogenesis is currently unknown. Hymecromone is a hyaluronic acid synthase inhibitor FDA approved for use in humans as a choleretic. We hypothesized that excessive production of hyaluronic acid by the airway epithelium, in response to SARS-CoV-2 infection, may increase hyaluronan fragments that augment epithelial dysfunction in COVID-19. We therefore evaluated a hyaluronic acid synthase inhibitor, hymecromone, for its potential to regulate the infection of respiratory epithelia by SARS-CoV-2. Using air-liquid interface models we evaluated the impact of SARS-CoV-2 infection on differentiated primary human airway epithelium in the BSL3 facility. At 100μg/ml hymecromone significantly inhibited the cytopathic effects of SARS-CoV-2 on airway epithelium (p<0.001). After 24 hours, SARS-CoV-2 virus accumulated in the basolateral compartment after apical infection of the airway cultures. Hymecromone also significantly inhibited this basolateral accumulation of viral particles versus untreated controls (p<0.05). Additionally, hymecromone alters the cytokine response to SARS-CoV-2 infection, dose-dependently decreasing apical secretion of cytokines including IL-17A/B/D, IL-21 and IL-5, and dose-dependently increasing the basolateral secretion of IL-17A/D and IL-1RA. All experiments were performed on three independent donor cells with three experimental repeats per condition. In conclusion, our data highlight the importance of the regulation of hyaluronic acid production in the response of the airway epithelium to SARS-CoV-2 infection and indicate hymecromone as a potential therapeutic option. Funding for this study was provided by the Rainwater Foundation. This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.