bluuebunny/crossref_metadata_2025_split huggingface dataset:
Insulin-Derived Endothelial Microvesicles Induce a Proinflammatory Endothelial Phenotype
Authors: Ostrander Emily , Garcia Vinicius , Fandl Hannah , Levy Ma'ayan , Stockelman Kelly , Goulding Anabel , DeSouza Noah , Greiner Jared , Hijmans Jamie , DeSouza Christopher 
Published: May 2023

Increased inflammation renders the vascular endothelium susceptible to atherosclerosis and thrombosis. Insulin has been shown to influence vascular function. Hyperinsulinemia is associated with a proinflammatory endothelial phenotype. In vitro, insulin has been shown to increase the inflammatory transcription factor NF-kB. Extracellular vesicles, particularly endothelial cell-derived microvesicles (EMVs), have emerged as mechanistic factors mediating of endothelial inflammation and, in turn, vascular disease. Circulating EMVs are elevated in metabolic conditions associated with hyperinsulinemia. However, whether insulin stimulates EMV release is unknown, and, if so, whether insulin-derived EMVs are proinflammatory. The experimental aims of this study were to determine: 1) if insulin stimulates EMV release from endothelial cells; and 2) whether insulin-derived EMVs promote a proinflammatory endothelial phenotype. Human umbilical vein endothelial cells (HUVECs) were cultured (3rd passage) and incubated with 1 nM insulin (concentration representing a hyperinsulinemic state) for 24 h. EMVs released into the supernatant from cells treated with insulin or vehicle were isolated and quantified by flow cytometry (CD144-PE). In separate experiments, HUVECs (2x106 cells/condition) were treated with either insulin, insulin-induced EMVs or control EMVs for 24 h. EMV release was markedly higher (~185%; P<0.05) in cells treated with insulin compared with control (88±10 vs. 31±5 EMV/μL). Insulin-generated EMVs induced significantly higher release of interleukin (IL)-6 (25.4±1.5 vs 20.1±1.2 pg/mL) and IL-8 (37.8±2.5 vs 27.1±2.7 pg/mL) than control EMVs. Although total NF-kB p65 expression was not significantly altered; insulin-derived EMVs induced ~30% higher (P<0.05) expression of phosphorylated-NF-kB p65 (Ser536; active NF-kB) (8.5±0.4 vs. 6.5±0.3 AU). The adverse effects of insulin-generated EMVs on IL-6, IL-8, and pNF-kB p65 were consistent with the proinflammatory effects of insulin. In summary, insulin induces an EMV phenotype that adversely affects endothelial cell inflammation. Insulin-generated EMVs may contribute to the proinflammatory vascular effects of insulin. Nothing to disclose 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 subjective pain ratings and sympathetic outflow during a cold pressor test
Authors: Chaudhry Laila , Coovadia Yasmine , Chen Celine , Usselman Charlotte 
Published: May 2023

Pain is the leading source of morbidity worldwide and a global clinical and societal challenge. Subjective pain scores are commonly employed in pain-centric research to quantify pain despite the presence of established organismic and environmental sources of intra- and interindividual variability in these scores. As a result, methods for the quantification of pain continue to be the focus of ongoing work in the pain field, including the search for objective biomarkers for pain.To that end, muscle sympathetic nerve activity (MSNA) has been proposed as an objective biomarker of pain. Therefore, the purpose of this study was to examine the relationship between changes in MSNA and changes in subjective pain ratings (PR) during an acute pain stimulus (i.e., cold pressor test (CPT)). Additionally, we examined whether MSNA measures were sensitive to within-subject changes in PR across time. We hypothesized that MSNA would be positively correlated with PR, and that both would increase steadily and concomitantly throughout a 6-minute CPT. We obtained integrated MSNA using peroneal microneurography (NeuroAmp, ADI; MSNA quantified as burst incidence (bursts/100hb)) during 10 minutes of supine rest and CPT in 10 young (aged 18-35 y) and healthy individuals (n=5 men). Participants reported PR on a numerical rating scale (0-10) at rest and during the CPT (timepoints: 30-s, 120-s, 240-s, and 330-s). One-way repeated measures ANOVAs assessed whether PR and MSNA changed over the CPT. PR increased over the CPT (p= 0.03) with a mean increase of 1±3 rating scale points from 30-s to 330-s. There was no main effect of time on MSNA (p=0.051), as it increased initially, but then decreased gradually thereafter. A linear regression analysis of the relationship between absolute PR and MSNA demonstrated a moderate positive correlation (r=0.43, p<0.01); however, relative changes in PR and MSNA over time (i.e., timepoints expressed relative to rest) were not correlated (r=-0.19, p=0.25). Meanwhile, acute changes in MSNA and PR from timepoint-to-timepoint (calculated as timepoint - previous timepoint) were strongly correlated (r=0.62, p<0.01). In summary, we observed similar patterns of change in subjective PR scores and MSNA during a CPT. These data suggest that MSNA is a valuable biomarker in the quantification of pain due to its consistency with subjective measures of pain. This research was funded by the National Science and Engineering Research Council of Canada. 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.
Use of the Peregrine Catheter Infusion System to develop novel targeted renal nerve ablation therapies in hypertensive sheep
Authors: de la Cruz-Lynch Arthur , Van Helden Dusty , Dayton Alex , Evans Louise , Ruiz Lauar Mariana , Osborn John 
Published: May 2023

Background and Objective: Clinical trials have shown that catheter-based total (efferent and afferent) renal denervation (TRDN) can effectively lower arterial pressure in patients with treatment-resistant hypertension (HTN). The Peregrine catheter infusion system deploys microneedles from the renal artery lumen into the renal artery adventitia to inject the neurolytic agent ethanol. The objective of this study was to utilize this catheter to develop novel renal denervation therapies in a large animal model. In this study our aim was to demonstrate that TRDN lowers arterial pressure in the deoxycorticosterone acetate and high salt diet (DOCA-salt) sheep model of HTN. This will establish the utility of this catheter to deliver the afferent nerve neurolytic agent, capsaicin. Our group has shown that selective afferent renal denervation (ARDN) lowers arterial pressure to the same degree as TRDN in DOCA-salt HTN rats. Our long-term goal is to translate these findings to the DOCA-salt sheep model and eventually humans. Methods: Adult Domestic sheep weighing 60-80 kg were implanted with a subcutaneous silicone pellet containing DOCA (350mg/kg) and given access to salted (0.2% NaCl) drinking water and (180mEq Na+/kg) feed. Stellar radio telemeters were implanted for continuous measurement of MAP. 30 days following induction of DOCA-salt HTN, the Peregrine catheter infusion system was used to perform bilateral TRDN. One month after TRDN, animals were terminated and kidneys were harvested to verify denervation efficacy. Preliminary Results: 30 days following implantation of DOCA, 24hr MAP increased ~25mmHg from a baseline of 99mmHg to 123mmHg (n=2). 30 days following TRDN, 24hr MAP decreased to near control levels of 105mmHg. Conclusion and Future Directions: These preliminary results demonstrate that TRDN with the Peregrine catheter lowers MAP in DOCA-salt HTN sheep. The mechanism underlying this response is still being investigated. Sheep studies are underway to utilize the Peregrine catheter to perform ARDN by injection of capsaicin into the renal artery adventitia. The goal is to conduct a translational study to move catheter-based ARDN into clinical trials. If catheter-based ARDN lowers MAP to the same degree as TRDN, efferent renal nerves could be preserved to maintain MAP and blood volume in response to hemorrhagic or septic shock. Supported by NHLBI R01 HL116476. 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 cellular circadian clock of Phox2b-expressing cells drives daily variation of the hypoxic but not hypercapnic ventilatory response in mice
Authors: Jones Aaron , Marino Gabriella , Spears Allison , Arble Deanna 
Published: May 2023

While the suprachiasmatic nucleus (SCN) controls 24-hour rhythms in breathing including minute ventilation (VE), the mechanisms by which the SCN drives these daily changes are not well-understood. Moreover, the extent to which the circadian clock regulates the ventilatory responses to hypercapnia and hypoxia (i.e., the ventilatory chemoreflex), is unknown. We hypothesized that the SCN regulates daily breathing and chemoreflex rhythms by synchronizing the molecular circadian clock within cells. Here, we used whole-body plethysmography to assess ventilatory function in transgenic BMAL1 knockout (KO) mice to determine the role of the cellular clock in regulating daily rhythms in ventilation and chemoreflex. We observed that, unlike their wildtype littermates, BMAL1 KO mice exhibited a blunted daily rhythm in VE and failed to demonstrate daily variation in the hypoxic ventilatory response (HVR). The absence of a functional cellular clock in BMAL1 KO mice also resulted in an overall decrease in the hypercapnic ventilatory response (HCVR) and a sex-specific absence of circadian variation of HCVR. Next, to determine the extent to which these effects on minute ventilation and ventilatory chemoreflex were mediated by the cellular clock within the neural respiratory network, we assessed ventilatory rhythms in BMAL1fl/fl;Phox2bCre/+ mice which lack BMAL1 in all Phox2b-expressing chemoreceptor cells (hereafter called BKOP). BKOP mice lacked daily variation in HVR consistent with our observations in the BMAL1 KO mice. However, unlike BMAL1 KO mice, BKOP continued to exhibit daily variations in VE and HCVR similar to wildtype littermates. These data indicate that the cellular clock contributes to the daily rhythms in VE, HVR, and HCVR. Moreover, the cellular clock of Phox2b-expressing cells specifically is necessary for day-night variations in HVR. Taken together, these data suggest that the SCN regulates daily ventilatory rhythms in part through the synchronization of cellular clocks within respiratory cell populations. These findings open the possibility that circadian disruption or circadian misalignment may affect respiratory homeostasis which, in turn, may have clinical implications for shift workers and respiratory diseases with time-of-day-specific symptomology. American Heart Association (Arble, 20IPA35320195) 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.
Pannexin 1 channels control CaV1.2 channel activity and vascular reactivity in diabetic hyperglycemia
Authors: Hong Junyoung , Hong Junyoung , Baudel Miguel Martin-Aragon , Reddy Gopyreddy R , Moustafa Yumna A , Ayende Jose W , Mohabbat Yaseen , Isakson Brant E , Nieves-Cintron Madeline , Navedo Manuel F 
Published: May 2023

Vascular complications are major causes of morbidity and mortality in diabetic patients. Recently, our group identified a novel purinergic signaling pathway involving the AKAP5/P2Y11/AC5/PKA/CaV1.2 protein network in arterial myocytes that is activated upon diabetic hyperglycemia leading to vasoconstriction. This purinergic complex is activated by the release of nucleotides (e.g. ATP) to the extracellular space in response to hyperglycemic conditions. Pannexin 1 (Panx1) is a channel that mediates ATP efflux, thus inducing purinergic signaling activation. In this study, we hypothesize that Panx1 is a critical regulator mediating ATP release and increasing cAMP synthesis, CaV1.2 potentiation, and vasoconstriction upon diabetic hyperglycemia. Consistent with this hypothesis, we found that elevated glucose (HG) induced an elevation in extracellular ATP concentrations, and this was reduced in the presence of the Panx1 inhibitor spironolactone (spiro). Panx1 was found in complex with AKAP5, P2Y11, AC5, PKA, and CaV1.2 in arterial myocytes. This protein complex was strengthened upon HG treatment, and spiro prevented this effect. Spiro and genetic ablation of smooth muscle Panx1 (iPanx1sm -/-) blocked cAMP production, CaV1.2 potentiation, sustained vasoconstriction, and in vivo elevations in cerebral artery myogenic tone and reduced blood flow in response to HG. In a mouse model of type 1 diabetes (e.g. STZ), the increased CaV1.2 potentiation and enhanced myogenic tone were prevented in arterial myocytes and arteries from iPanx1sm -/- mice. Altogether, these data suggest that Panx1 is part of the AKAP5/P2Y11/AC5/PKA/CaV1.2 signaling module in arterial myocytes. This Panx1-led complex modulates CaV1.2 activity and vascular reactivity in response to diabetic hyperglycemia. Thus, Panx1 could be a new therapeutic target to treat vascular complications during diabetes. This work was supported by NIH grants R01HL149127, R01HL121059, and R01HL161872 (to MFN). 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.
Exercise Hyperemia Following Ischemia-Reperfusion
Authors: Hanson Brady , Miller Kayla , Casey Darren , Hanada Satoshi , Feider Andrew , Aldrich Aric 
Published: May 2023

Prolonged ischemia can result in cellular dysfunction. Paradoxically, the reintroduction of blood flow (reperfusion) can lead to further damage, described as ischemia-reperfusion injury (I/R). It has been reported that I/R attenuates endothelial function at the micro- and macrovascular level. An attenuation in microvascular endothelial function from I/R may therefore disrupt the ability to modulate exercise hyperemia in contracting skeletal muscle. We tested the hypothesis that I/R blunts the rapid and steady-state hyperemic and vasodilatory response to rhythmic handgrip exercise. Ten young healthy subjects (8M/2F; 24 ± 1 yr) completed two separate study visits (I/R and time control trials) in a random order. On each study visit rapid-onset hyperemia and vasodilation following a single forearm contraction was assessed in duplicate. Rhythmic handgrip exercise (20 contractions per min) was then completed for 3 min. All handgrip exercises were performed at 20% maximum voluntary contraction. Following exercise, either I/R was induced (pneumatic cuff placed around the upper left arm at 240 mmHg for 20 min followed by 20 min of reperfusion) or a time control trial (supine rest for 40 min) was completed. Handgrip exercises were then repeated immediately after each respective intervention. Brachial artery blood velocity and diameter were measured with Doppler ultrasound and forearm vascular conductance (FVC) was calculated as forearm blood flow (FBF; ml·min-1) over blood pressure (mmHg). In response to a single muscle contraction, peak hyperemia (ΔFBF from baseline) and vasodilation (ΔFVC) were attenuated following I/R (134 ± 15 vs. 103 ± 13 ml·min-1; 160 ± 17 vs. 118 ± 15 ml·min-1·100 mmHg-1, P<0.05 for both) but not following time control (115 ± 20 vs. 124 ± 18 ml·min-1; 150 ± 25 vs. 148 ± 20 ml·min-1·100 mmHg-1, P=0.16 and P=0.95, respectively). Total FBF and FVC following a single muscle contraction was not different between I/R (25 ± 4 vs. 20 ± 3 ml; 33 ± 5 vs. 24 ± 4 ml·100 mmHg-1) and time control (21 ± 4 vs. 23 ± 4 ml; 28 ± 5 vs. 28 ±4 ml·100 mmHg-1) trials (group x time interactions P=0.05 and P=0.08, respectively). Steady-state ΔFBF and ΔFVC during rhythmic exercise was unchanged in both I/R (192 ± 16 vs. 190 ± 17 ml·min-1; 208 ± 18 vs. 193 ± 19 ml·min-1·100 mmHg-1) and time control (188 ± 17 vs. 196 ± 15 ml·min-1; 206 ± 19 vs. 207 ± 15 ml·min-1·100 mmHg-1) trials (group x time interactions P=0.34 and 0.21, respectively). Our data indicate that 40 min of I/R blunts hyperemia and vasodilation at the onset of skeletal muscle contraction, but does not appear to attenuate these responses during steady-state rhythmic exercise. 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.
Muted molecular responses to thermal stress in the Antarctic emerald rockcod (Trematomus bernacchii): Proteomic evidence and possible evolutionary mechanisms
Authors: Dowd Wes , Kueltz Dietmar 
Published: May 2023

The Antarctic emerald rockcod ( Trematomus bernacchii) and its relatives have long been of interest to comparative physiologists, given their history of isolation in extremely cold waters and indications that they lack some or all of the classic “heat shock response.” In this study we complemented previous transcript-level analyses with a comprehensive assessment of the proteomic response to elevated temperatures across three tissues (gill, head kidney, and brain). Animals were exposed to constant conditions at one of three acclimation temperatures, after which a subset were sampled and the remaining individuals experienced an acute heat stress with or without recovery (n=5-6 per treatment). Protein expression patterns were analyzed using tissue-specific, data-independent acquisition (DIA) assay libraries on a UPLC-MS system. The expression patterns reveal a muted response to these different thermal challenges, with only a small number of proteins (out of 2721-3421 per tissue) differentially expressed for any given tissue-treatment combination. The magnitudes of expression changes were also small. These results appear to contradict relatively robust induction patterns for a subset of cellular stress response genes obtained from previous transcriptomic analyses. Furthermore, the differentially expressed proteins were not functionally enriched for any Gene Ontology or KEGG database entries, nor were the promoter regions of the corresponding genetic loci consistently enriched for any transcription factor binding motifs, including those that might be predicted to play a role in the response to hyperthermal stress (such as Hsf1 or HIF). Subsequent bioinformatics approaches within the Perciformes clade suggest modifications to the suite of proteins that regulate translation as a plausible explanation for the lack of a coordinated response to thermal stress in the Antarctic lineage. Overall, our proteomics data offer further detail into the physiological underpinnings of stenothermy in Antarctic fishes. NSF IOS-165582 to WD and an APS John F. Perkins, Jr., Research Career Enhancement Award 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 effect of sex on sympathetic transduction during an acute pain stimulus
Authors: Coovadia Yasmine , Chaudhry Laila , Fraser Graham , Usselman Charlotte 
Published: May 2023

Previously, we have noted sex differences in beat-by-beat fluctuations in blood pressure following sequences of muscle sympathetic nerve activity (MSNA; i.e. sympathetic transduction) during acute sympatho-inhibition but not at rest. However, sex differences in sympathetic transduction during sympatho-excitation have yet to be examined. Therefore, we tested the hypothesis that sympathetic transduction during acute sympatho-excitation and recovery from sympatho-excitation are greater in men than women. We tested healthy women (n=5) and men (n=5) of similar age (26±4 vs 23±2y, respectively; P=0.3). Integrated MSNA (microneurography; NeuroAmp, ADInstruments) and beat-by-beat blood pressure (finger photoplethysmography; Finometer MIDI) were assessed during 10 minutes of supine rest, an acute pain stimulus (6-minute cold pressor test; CPT), and recovery (6-minutes). Custom software was used to calculate sympathetic transduction: beat-by-beat changes in mean arterial pressure (MAP) were tracked for 15 subsequent cardiac cycles (expressed relative to the cardiac cycle associated with the final burst or non-burst in the sequence). Like sequences were overlaid and averaged. Prevailing MSNA and MAP were not different between women and men at rest (9±8 vs 8±5 bursts/min, P=0.8; 88±6 vs 97±6 mmHg, P=0.06) or during the CPT (21±10 vs 16±6 bursts/min, P=0.3; 98±5 vs 104±6 mmHg, P=0.1). However, during recovery, MSNA was greater in women than men (21±8 vs 10±4 bursts/min, P=0.03), despite similar MAP (95±5 vs 99±6 mmHg, P=0.3). Peak and nadir changes in sympathetic transduction following burst and non-burst sequences were not different between women and men at rest (burst: 1.55±0.46 vs 1.67±0.27mmHg, P=0.6; non-burst: -2.21±1.88 vs -2.26±0.36mmHg, P=0.9) or during the CPT (burst: 1.06±0.32 vs 0.45±0.47mmHg, P=0.08; non-burst: -3.24±1.44 vs 1.90±0.46mmHg, P=0.1). Sympathetic transduction following a burst of MSNA did not differ between the sexes during recovery (1.73±0.34 vs 1.65±0.23mmHg, P=0.7), while nadir decreases in MAP following non-burst sequences during recovery were more pronounced in women than men (-2.81±0.75 vs -1.56±0.91mmHg, P=0.04). Taken together, although sympathetic transduction did not differ between the sexes during the CPT, these data suggest that women may require heightened MSNA during recovery from acute stress to maintain equivalent blood pressure. This project was funded by McGill University, FRQS, and NSERC. 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.