bluuebunny/crossref_metadata_2025 huggingface dataset:
β‐amyloid Peptide‐Induced Human Arteriole Endothelial Dysfunction is Attenuated by Nanoliposomes
Authors: Guzman‐Villanueva Diana , Madine Jill , Truran Seth , Davies Hannah , Burciu Camelia , Franco Daniel , Weissig Volkmar , Migrino Raymond
Published: June 2021

Microvascular impairment is an under‐recognized pathologic mechanism of misfolded protein diseases and is critical in early Alzheimer's disease (AD). We showed that β‐amyloid 42 (Aβ), a peptide involved in AD, induces endothelial dysfunction in human adipose/leptomeningeal arterioles. Nanoliposomes (NL) are phospholipid containing particles that altered the structural properties of another amyloid protein (AL amyloid light chains) and restored endothelial function.

Aim

To determine if phosphatidic acid (PA) containing NL (NLPA) prevent Aβ fibril formation and restore endothelial function in human arterioles exposed to Aβ.

Methods

NLPA (70% cholesterol, 25% phosphatidylcholine, 5% PA) were mixed with Aβ and fibrillation rate measured by thioflavin T fluorescence. Human abdominal subcutaneous adipose arterioles were isolated and constricted with endothelin‐1. Baseline control dilation was measured following acetylcholine (10‐9‐10‐4M) and papaverine (10‐4M); after washing arterioles were exposed to 2 µM Aβ±NLPA (1:10 mass) and dilator response was measured. Human umbilical vein endothelial cells (HUVEC) were exposed to Aβ±NLPA (24 hrs) and nitric oxide (NO) gas was measured.

Results

NLPA prevented Aβ fibril formation (F1). Aβ induced impaired dilator response to acetylcholine and papaverine while reducing HUVEC NO (F2). These changes were attenuated by NLPA.

Conclusions

NL prevent Aβ amyloid fibril formation. NL reduce Aβ‐induced endothelial and non‐endothelial arteriole dysfunction, the former likely by increasing NO. Nanoliposomes represent a novel treatment approach to amyloid protein diseases such as AD.

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Arterial Stiffening in Human Hypertension: Is there a contribution of the sympathetic nervous system?
Authors: Prodel Eliza , Barbosa Thales , Machado Alessandro , Mansur Daniel , Nobrega Antonio Claudio , Vianna Lauro
Published: June 2021

Arterial stiffness (Alx) is recognized as an important prognostic index and potential therapeutic target in patients with hypertension. However, its pathophysiological mechanism is yet not fully understood. Another common feature in human hypertension is the excessive central sympathetic nerve activity. Given this, we tested the effects of sympathetic stimulation on arterial stiffness in eight hypertensive men (52±1 yrs; 140.4±0.1/90.5±0.1 mmHg). To accomplish that, heart rate (HR, ECG), blood pressure (BP, Omron), AIx (radial artery, SphygmoCor), muscle sympathetic nerve activity (MSNA, peroneal nerve) and femoral vascular conductance (FVC, Doppler) were measured at rest and during sympathetic stimulation induced by trigeminal nerve stimulation (TGS) using an ice pack on the forehead and by isolated muscle metaboreflex activation via post exercise muscle ischemia (PEI). HR was similar to baseline in both TGS and PEI (baseline: 63±2.1 bpm, TGS: 65±2.4 bpm, PEI: 62±3.0 bpm, P=0.7). BP increased during sympathetic stimulation (TGS: +31±13 mmHg; PEI +24±1 mmHg; P<0.05 vs. baseline). MSNA increased by 115±7% during TGS and by 54±5% during PEI. Consequently, FVC was significantly reduced (P<0.05) during both TGS (‐23±0.6%) and PEI (‐51±1.3%). Similarly, AIx increased significantly from baseline during both maneuvers (TGS +14.3±0.3; PEI +10.8±0.1 p<0.05 vs. baseline). Increases in MSNA were strongly associated with increases in Alx (r=0.91; P<0.05). In conclusion, our results demonstrate that an excessive central sympathetic outflow is likely one of the mechanisms that modulates arterial stiffening in human hypertension.
Effect of Ultrasonic Bone Stimulation of the Mastoid on Renal and Coronary Blood Flow in Humans
Authors: Ray Chester , Park Susie , Sauder Charity
Published: June 2021

We have previously demonstrated that external stimulation of the otolith organs by ultrasonic bone stimulation (UBS) of the mastoid increases muscle sympathetic nerve activity. These responses are similar to that observed by head‐down rotation. Additionally, stimulation of the vestibulosympathetic reflex by head‐down rotation elicits leg and renal vasoconstriction. The purpose of this study was to determine if UBS elicits vascular changes to the renal and coronary arteries. We hypothesized that UBS would elicit vasoconstriction in the renal but not the coronary vascular bed. Ten subjects (3 F, 7 M; 25±1 yr; 174.0±3.2 cm; 71.8±4.3 kg) performed UBS in the supine position for 3 min during measurement of arterial blood pressure, heart rate, renal blood flow, and coronary blood flow. Blood flow was measured using Doppler ultrasound. UBS did not change mean arterial blood pressure (Δ‐1±1 mmHg) or heart rate (Δ‐1±1 beats/min) from baseline. Renal vascular conductance was significantly decreased from baseline during UBS (0.63±0.03 and 0.60±0.04 cm/s/mmHg, respectively; P=0.02). However, there were no changes in coronary vascular conductance during UBS (0.18±0.01 and 0.18±0.02, for baseline and UBS, respectively). In conclusion, UBS can elicit vasoconstriction of the renal vascular bed similar to that observed during head‐down rotation. This finding suggests that external stimulation of the otolith organs might assist in postural blood pressure regulation in people with decreased orthostatic tolerance.

Supported by: NIH R21HL109952
An Examination of Long‐Term Fluctuations in Arterial Pressure in the Prairie Vole
Authors: Lewis Robert , Benjamin Bruce , Curtis J.
Published: June 2021

Mean arterial pressure exhibits circadian and longer‐term fluctuations that occur over days, weeks and months. From a clinical perspective, such oscillations in arterial pressure contain prognostic information about cardiovascular risk and mortality. Unfortunately, long‐term blood pressure monitoring is not tolerated well by human subjects, making long‐term blood pressure oscillations difficult to study. To avoid this limitation, we implanted blood pressure transducers in the left common carotid artery of male prairie voles allowing us to continuously record arterial pressure in freely moving animals over an extended period of time. Prairie voles show promise as a model for cardiovascular regulation. Previous research has shown that prairie voles have cardiac and behavioral cycles that display ultradian rhythms, allowing several cycles to be observed within a single 24‐hour period. Moreover, as in humans, prairie voles display a resting heart rate that is lower than what would be predicted by allometric scaling, suggesting that cardiovascular regulation in both humans and prairie voles is disproportionately influenced by the parasympathetic branch of the autonomic nervous system. The shared patterns of cardiovascular regulation and their relatively short biorhythms make the prairie vole a potentially useful model in which to study rhythmic variations in cardiovascular function. The goal of this line of research is to further develop the prairie vole as tractable model in which to study the mechanisms that regulate long‐term cardiovascular rhythms.
MK2 Phosphorylates Capase 3 and Regulates Nuclear Translocation of Cleaved Caspase 3 during LPS mediated Apoptosis
Authors: Damarla Mahnendra , Johnston laura , Kim Bo , Kolb Todd , Damico Rachel , Merchant Michael , Rane Madhavi , Machamer Carolyn , Hassoun Paul
Published: June 2021

Background

Apoptosis is a necessary event in the development of acute lung injury (ALI). Recent reports have identified nuclear translocation of active caspase 3 is necessary for the execution of apoptosis. The molecular mechanism(s) by which cleaved caspase 3 translocates to the nucleus are not well understood.

Methods

Wild Type and MK2‐/‐ mice were exposed to intravenous (IV) lipopolysaccharide (LPS), after which lungs were harvested for tissue analyses. Kinase activity assays using MK2 and caspase 3 were also performed.

Results

In response to IV LPS, WT mice exhibited a significant increase in apoptosis accompanied by increases in markers of lung injury. However, MK2‐/‐ mice were protected from both apoptosis and lung injury. Interestingly, cleaved caspase 3 translocated to the nucleus in WT mice while it was sequestered in the cytosol in MK2‐/‐ mice. 2‐D gel analyses of caspase 3 in lung lysates from LPS exposed WT mice demonstrated a shift toward the positive electrode on an isoelectric gradient. This shift was lost with phosphatase pretreatment; appearing identical to lysates from MK2‐/‐ mice exposed to LPS. Furthermore, protein kinase assays confirmed that MK2 directly phosphorylates caspase 3 and mass spectrometry analysis identified two potential phosphorylation sites.

Conclusion

Taken together, our results suggest that caspase 3 is a potential substrate of MK2 and, once modified (i.e. phosphorylated), undergoes differential processing, which may account for the differential localization once cleaved in MK2 deficient states.
Activation of Anoctamin‐1 Causes Apoptosis of Pulmonary Vascular Endothelial Cells
Authors: Allawzi Ayed , Vang Alexander , Choudhary Gaurav
Published: June 2021

Background

We have shown that Anoctamin‐1 (Ano1) is expressed in pulmonary endothelial cells (ECs) and causes EC hyperpolarization. However, the functional role of Ano1 in pulmonary vascular ECs is unknown. We sought to elucidate the role of Ano1 in EC proliferation.

Methods

Changes in Ca2+ levels were assessed using Fluo‐4 AM. Changes in ECs cell numbers were performed by haemocytometer counts. p38 phosphorylation was probed using immunoblot. Cell cycle and apoptosis was assessed using flow cytometry and PI or Annexin V/PI staining respectively.

Results

Activating Ano1 resulted in a significant change in Ca2+, however there was some heterogeneity with some cells exhibiting marked increases in Ca2+. Cell counts revealed that activation of Ano1 significantly decreased cell number, that was attenuated in presence of chloride channel inhibitors, DIDS and T16Ainh‐A01. Ano1 activation did not alter cell cycle progression but increased p38 phosphorylation, and preliminary data suggest increased apoptosis.

Conclusion

Ano1 is expressed in the pulmonary endothelium and activation leads to a decrease in cell number, likely mediated via apoptosis.
Decreased PGC‐1α‐SIRT1 Signaling Leads to Impaired Angiogenesis in Persistent Pulmonary Hypertension of the Newborn (PPHN)
Authors: Konduri Girija , Callan Emily , Afolayan Adeleye , Teng Ru‐Jeng
Published: June 2021

Introduction

PPHN is characterized by increased pulmonary vascular resistance (PVR) at birth resulting in hypoxemia. Impaired angiogenesis contributes to high PVR in PPHN. Pulmonary artery endothelial cells (PAEC) in PPHN show decreased mitochondrial respiration, increased apoptosis and impaired angiogenesis. Objective: Investigate the hypothesis that down‐regulation of Peroxisome Proliferator‐Activated Receptor Gamma Co‐Activator‐1α (PGC‐1α) and histone deacetylase, Sirtuin‐1 (SIRT‐1) lead to impaired mitochondrial biogenesis and angiogenesis in PPHN. Methods: PAEC were isolated from fetal lambs with PPHN induced by prenatal ductus arteriosus constriction from 80% to term gestation and matched controls. PGC‐1α and SIRT‐1 levels were evaluated by immunoblotting. PGC‐1α was knocked down in control PAEC and overexpressed in PPHN PAEC to investigate effects on mitochondrial complex proteins I‐V and angiogenesis. Angiogenesis was assessed in vitro by tube formation, cell migration and proliferation. Results: PPHN PAEC had significant decreases in PGC‐1α and SIRT‐1 levels vs. controls (p<0.01). PGC‐1α knockdown in control PAEC lead to decreased tube formation (p<0.0001), cell migration (p<0.01) and proliferation (p<0.0001). PGC‐1α over‐expression in PPHN PAEC lead to significant increases in mitochondrial ETC proteins‐ complex I (p<0.0001), II (p=0.0433), III (p=0.0384), and V (p=0.0462), as well as increased tube formation (p<0.0001), cell migration (p<0.01) and proliferation (p<0.0001).

Conclusion

Coordinated downregulation of PGC‐1α and SIRT1 contribute to decreased mitochondrial biogenesis and angiogenesis in PPHN. This mechanism offers a new therapeutic target in PPHN.
Loss of Primary Cilia Induces the Appearance of a Non‐Selective Cation Channel in the Apical Membrane of Mouse CCD Principal Cells
Authors: Saigusa Takamitsu , Yue Qiang , Thai Tiffany , Bell P.Darwin , Eaton Douglas
Published: June 2021

Polycystic kidney disease (PKD) is a ciliopathic disorder, which produces gross abnormalities in the kidney, making the initial events in the disease difficult to study. Cysts in PKD arises mostly from the collecting duct, but the mechanism by which cilia promotes cyst formation is unknown. We used adult Ift88 (cilia) conditional knockout mouse, an autosomal recessive PKD model, with or without tamoxifen inducible Cre. Two weeks after inducing Cre, we examined the effects of ciliary loss on single channels in the apical membranes of principal cells of isolated, spit open CCDs in 17 Cre+ and 24 Cre‐ tubules (8 mice each). 4 Cre+ and 11 Cre‐ tubules had measurable channel activity. Channels in Cre‐ mice were all 5pS Na+ selective channels with long mean open times (475.7 ± 83.26 ms) and Po greater than 0.2 very similar to previously reported ENaC channels. Cre+ principal cells had two types of channels. One cell had an ENaC‐like channel, but all of the cells had 21 pS non‐selective cation channels (reversal potential near zero) with short mean open times (72 ± 17 ms) an open probability <0.08 and a characteristic flickery opening. This is similar to the previous reported 23 pS non‐selective cation channel (NSC) seen in a collecting duct cell line derived from mouse of Ift88 hypomorph (PLoS One. 2013; 8(8): e73424). We interpret these results to imply that an early event in ciliary loss is the induction of a NSC channel at the apical membrane. Whether this channel is the same as the TRPV4/polycystin 2 channel that was identified in cell culture remains to be determined.
Characterizing Renal Dysfunction in the Face of Hypertension and Heart Failure
Authors: Brooks Steven , Frisbee Jefferson , Chantler Paul , Olfert Mark , Brock Robert
Published: June 2021

Recent work highlights how small decrements in renal function, even those that are transient, have significant negative prognostic effects on outcomes in patients with heart failure. Yet, it is unclear if heart failure secondarily leads to diminished renal function or if mild renal dysfunction leads to progression of functional cardiac deterioration.

To better understand the association between the concomitant development of renal dysfunction and heart failure, a comprehensive assessment of renal function in the male spontaneously hypertensive, heart failure‐prone rat (SHHF) was performed. Various biomarkers of renal function were evaluated. At 37‐40 weeks, severe hypertension (MAP greater than 170) was measured in all SHHF rats. Serum albumin content in the SHHF was significantly diminished throughout the experimental period, indicating the possibility of renal dysfunction. Although the ratio of serum urea to creatinine increased significantly in SHHF, creatinine levels remained normal, suggesting that renal filtration is likely not compromised and that the increase is a reflection of inadequate blood flow. To corroborate this possibility further, cortical peritubular capillary networks were imaged using intravital microscopy and showed that renal microvascular blood flow in SHHF was, in fact, diminished.

Together, these data confirm that renal dysfunction occurs in the setting of hypertension and heart failure, and is an early manifestation of blood flow deficits. We now offer an alternative pathway to the conventional thinking of the cardiorenal axis that should serve as a stimulus for developing novel therapeutic interventions for heart failure.
Stearoyl‐CoA Desaturase mRNA in Channel Catfish: A Potential Molecular Marker to Investigate Development of Obesity Using Non‐model Fish Species
Authors: Nash Claire , Evans Paige , Kobayashi Yasuhiro
Published: June 2021

Objectives of the present study were to characterize SCD‐1 gene in channel catfish and examine its mRNA expression in various tissues. Genetic selection toward increased growth results in development of obesity‐like phenotype in channel catfish, suggesting that channel catfish may serve as an alternative animal model to study human obesity development. However, the underlying mechanism(s) that results in the development of obesity‐like phenotype, as well as the consequence of developing such a phenotype, is unclear. In mammals, development of obesity leads to changes in expression and function of various enzymes involved in lipid metabolism such as stearoyl‐CoA desaturase‐1 (SCD‐1). Currently, little is known about the role of SCD‐1 in channel catfish physiology. Channel catfish expressed sequence tag clones that correspond to the zebrafish SCD‐1 sequence were identified and used as templates to generate primers for the RT‐PCR. The PCR amplicon (599 bp) was generated from channel catfish liver cDNA and shared high sequence similarity (around 70%) with SCD‐1 mRNA of various fish species. Expression of SCD‐1 mRNA was detected in brain, liver, and kidney. Currently, changes in expression of SCD‐1 mRNA in relation to changes in food intake and genetic selection toward growth are being investigated. This project is supported by the Kansas IDeA Network of Biomedical Research Excellence.
Truncated Variant of ASIC2b Confers Epithelial Sodium Channel Properties to ASIC2: Role in Nephrotic Syndrome
Authors: Doucet Alain , Sassi Ali , Brideau Gaelle , Cheval Lydie , Vogt Bruno , Fila Marc
Published: June 2021

Sodium retention responsible for nephrotic edema stems from epithelial sodium channel (ENaC) and Na,K‐ATPase induction in cortical collecting ducts (CCD) of puromycin aminonucleoside (PAN) nephrotic rats. However PAN rats show hyper‐aldosteronemia whereas most nephrotic patients do not. Aldosterone‐clamped (AC) PAN rats still retain sodium in ASDN although ENaC is no longer expressed. We searched for an alternate sodium entry pathway in CCD from AC‐PAN rats, a more relevant model of human disease.

By RACE we isolated from AC‐PAN rat kidney a cDNA identical to that of ASIC2b except that it lacks the 207 3′‐most nucleotides. This truncated sequence contains an ATG within the reading frame of the full length sequence. Heterologous expression in OKP cells demonstrated that it is translated in a protein lacking the 71 N‐ter amino acids. Two‐electrode voltage clamp analysis in Xenopus ovocytes showed that co‐expression of truncated ASIC2b and ASIC2a induces an acid‐stimulated cation current which, instead of being transient, lasts as long as the stimulus is maintained. ASIC2a and truncated‐ASIC2b thus constitute heteromeric channels potentially supporting epithelial sodium transport. ASIC2b expression is induced in CCD of AC‐PAN rats where it localizes at the apical pole. ASIC2b was detected in kidney biopsies from 5/8 patients with idiopathic nephrotic syndrome but not in 26/26 patients with other renal diseases. In ASIC2b‐positive nephrotic patients, ASIC2b was located in CCD.

Results suggest that truncated ASIC2b/ASIC2a mediates sodium retention in nephrotic syndrome and appears as a new therapeutic target.
Activation of Cardiogenic Fate of C‐kit+ Cardiac Progenitor Cells in Doxorubicin Induced Cardiotoxicity
Authors: Zhu Wuqiang , Bender Ingrid , Yellamilli Amritha , van Berlo Jop
Published: June 2021

Cardiac regeneration is partly regulated by c‐kit+ cardiac progenitor cells (CPC). Doxorubicin (DOX) is an effective anticancer chemotherapeutic which induces cardiotoxicity. To what extent c‐kit+ CPCs are activated in response to DOX treatment and their fate remains unknown. Here, we used the following genetic mouse models to characterize the contribution of c‐kit+ CPCs to cardiac repair mechanisms after DOX; c‐kit Cre‐IRES‐GFP mice to mark all cells that currently express the kit locus, c‐kit MerCreMer(MCM) cross‐bred to R26‐GFP reporter mice to mark CPC derived cells using inducible genetic lineage tracing, and c‐kit MCM cross‐bred to R26‐mT/mG double fluorescent reporter mice to differentiate de novo cardiomyocyte from cell fusion. Two‐month‐old mice were treated with DOX (20 mg/kg cumulative dose). Echocardiography one week after DOX injection showed significantly depressed cardiac function accompanied by cardiomyocyte apoptosis using immunohistochemistry for cleaved caspase 3. Furthermore, DOX activates expression of GATA4 specifically in CPCs. Presumably as a consequence of increased Gata4 expression, genetic lineage tracing of CPCs showed a significant increase (25‐fold) in cardiomyocyte formation, mostly newly formed. Interestingly, this was not at the expense of endothelial fate commitment. In conclusion, DOX enhances c‐kit+ CPC cardiomyocyte commitment and differentiation. We are currently unraveling the underlying molecular pathways to enhance the myogenic potential of c‐kit+ CPCs to repair injured hearts.
Inhibition of P2X7 Alters Wound‐Induced Ca2+ Mobilization and Cytoskeletal Rearrangements
Authors: Minns Martin , Teicher Gregory , Rich Celeste , Trinkaus‐Randall Vickery
Published: June 2021

The process of wound healing involves a complex network of signaling pathways working to promote rapid migration and wound closure. Secreted nucleotides and purinergic receptors have been shown to play a major role in the calcium wave and subsequent calcium‐dependent signaling that is essential for proper healing. While the P2X7 purinergic receptor has been shown to promote migration, its exact role in this process is still relatively unknown. In this study, we show that P2X7 is down‐regulated after injury, but localizes to the leading edge of migrating corneal epithelium in organ culture. Inhibition of the P2X7 receptor prevents this leading‐edge localization and delays wound healing. In addition, we show that inhibition of P2X7 leads to an attenuated Ca2+ mobilization and to a more rapid decline in the calcium wave after injury. In cell culture, inhibition of P2X7 results in fewer focal adhesion clusters and delayed migration. Live cell imaging reveals that P2X7 is required for membrane ruffling after scratch wounding. Together, these data demonstrate the importance of P2X7 in the early signaling events that promote epithelial cell migration.
Sirtuins as negative regulators of cardiac fibrosis
Authors: Samant Sadhana , Bindu Samik , Ghorpade Prabhakar , Pillai Vinodkumar , Gupta Mahesh
Published: June 2021

Background and Objective

Fibrosis results from a process where quiescent resident fibroblasts in a healthy tissue get transformed into myofibroblasts (myoFB). In the US an estimated 45% deaths per year are attributed to fibrotic diseases. Tissue fibrosis is considered one of the causative factors of the aging process and organ dysfunction. Sirtuins, the NAD+‐dependent deacetylases are shown to impact lifespan of organisms. Among the seven sirtuin isoforms expressed in mammalian cells, SIRT6 and SIRT3, which are localized in the nucleus and mitochondria, respectively, are shown to retard the aging‐associated diseases. We therefore set out to study their roles in development of tissue fibrosis.

Methods and Results

Fibroblasts isolated from human failing hearts showed increased expression of myoFB markers, including expression of α‐smooth muscle actin, fibronectin and collagen1 with concomitant decreased levels of SIRT6 and SIRT3. By immunoblotting and Masson‐trichrome staining we also observed up‐regulation of these myoFB markers in SIRT6(+/‐) and 12‐month old SIRT3(‐/‐) hearts, compared to age‐matched littermates,. These hearts also showed up‐regulation of TGF‐β1 and Smad3 levels. In experiments where SIRT3 or SIRT6 knocked‐down human cardiac fibroblasts were challenged with the pro‐fibrotic agonist angiotensin‐II, we observed significantly higher levels of TGF‐β1 and myoFB markers, compared to control fibroblasts. Over‐expression of these sirtuin isoforms reverted back the myoFB phenotype.

Conclusion

Though, SIRT6 and SIRT3 are localized in two different cellular compartments, both are capable of restraining TGF‐β signaling and blocking transformation of fibroblasts into myoFB. These sirtuins therefore can be considered candidates for designing anti‐fibrotic drugs. .
Comparison of Post‐Exercise Muscle and Neutrophil Transcriptomes Using Weighted Gene Co‐Expression Network Analysis
Authors: Peake Jonathan , Sampson Dayle , Broadbent James , Bulmer Andrew , Neubauer Oliver
Published: June 2021

We used weighted gene co‐expression network analysis (WGCNA) to identify clusters (modules) of highly correlated genes in circulating neutrophils and skeletal muscle after exercise. Eight endurance‐trained men performed 1 h intense cycling and 1 h intense running. Venous blood samples and skeletal muscle biopsies were collected before exercise, 3, 48 and 96 h after exercise. RNA was extracted from isolated neutrophils and homogenized muscle tissue. Illumina microarrays were used to generate an expression‐set from 27,626 probes, which was filtered down to 14,855 probes by removing redundant and low‐variance probes. Averaging those probes that mapped to the same gene symbol produced a quantitative dataset consisting of 7,548 gene symbols that were then used for WGCNA.Networks were constructed from neutrophil and muscle expression data at each timepoint. These networks were optimized using soft‐thresholding, followed by removal of noise and spurious network associations before comparing the neutrophil transcriptome against the muscle transcriptome as a comparator. The greatest degree of conservation between the neutrophil and muscle transcriptomes was evident at 48 h after exercise. This preliminary analysis suggests that the neutrophil transcriptome can be used as a proxy measure of changes in gene expression within skeletal muscle after exercise.
Blood Pressure Responses to Isometric Handgrip in Women With and Without a History of Hypertensive Pregnancy
Authors: Ranadive Sushant , Harvey Ronee , Miller Virginia , Joyner Michael , Barnes Jill
Published: June 2021

Hypertensive pregnancy (HP) is considered a risk factor for cardiovascular disease. Blood pressure (BP) response to physical stressor is an independent marker of cardiovascular risk. However, there is limited data regarding the pressor response to acute physical stress in women with a history of HP. Hence, the aim of the study was to compare BP responses in women with a history of HP to age and parity matched controls.

Beat to beat BP was recorded in postmenopausal women (age = 59 ± 1 yrs, BMI = 31 ± 2 kg/m2) with and without a history of HP at baseline and during isometric handgrip (HG) exercise (30% of MVC) to fatigue. Isometric handgrip exercise was followed by 90 seconds of supra‐systolic cuff occlusion on the exercising arm.

In both groups combined (N=31), systolic blood pressure (SBP) increased significantly from baseline to HG to cuff inflation (143 ± 3 to 161 ± 3 to 167 ± 4 mmHg). Similarly, mean arterial pressure (MAP) increased significantly from baseline to HG to cuff inflation (106 ± 2 to 119 ± 2 to 122 ± 2 mmHg). Diastolic pressure (DBP) increased significantly only from baseline to HG (80 ± 1 to 88 ± 1 mmHg) and baseline to cuff inflation (89 ± 2 mmHg). However, there were no significant differences in SBP, DBP and MAP between women with and without a history of HP (p>0.05).

Even though both groups had an increase in BP variables in response to HG and cuff occlusion, there was no difference in the BP response to acute physical stressors in women with a history of HP as compared to control participants.

Funding: National Institute of Aging 1P50AG044170‐01 and CTSA UL1 TR000135 and HL 118154 (JNB)
Correlation of Body Mass Index and Cardiovascular Reactivity to Exercise Induced Stress in Young Adults.
Authors: Mohesh Glad , Prasath Ajith , Palanisamy Poornima , Vijayakumar Abinaya , A Sundaramurthy
Published: June 2021

Cardiovascular reactivity (CVR) is an increase in heart rate and blood pressure when exposed to stress. Increased CVR to stress is an indicator of developing hypertension. In this study we have tried to understand if exaggerated CVR and obesity are related to each other.

Methods

Institutional Ethics Committee (Human Studies) clearance was obtained and a convenient sampling of 32 females and 32 males were done based on their age(>18 to <25years), and normotensive status. Baseline blood pressure, heart rate and five minutes finger photoplethysmography was recorded. Pulse wave contour analysis gave the pulse transit time, stiffness index and reflection index. A pedometer was hooked to the waistband of the subject and was asked to walk around the department corridor with an average speed of 100 steps in 1 minute to count 3000 steps in 30 minutes. After 3000 steps, immediate measurement of heart rate, blood pressure, and finger plethysmography for 5minutes was done in supine lying position. Pearson's correlation method and paired t test was done with statistical significance set at p<0.05.

Results

A positive correlation existed between the BMI and various reactivity measures of the heart rate, systolic blood pressure and diastolic blood pressure .A definite trend of positive correlation was noticed

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There was an inverse relationship between the BMI and elasticity of the arteries.

Conclusion

Autonomic nervous system is the most powerful energy saving regulatory system in our body. Failure of this system will lead to deposition of fat in one's body leading to Obesity. Reduced autonomic activity in obese subjects is a risk factor for cardiovascular morbidity.
Metabolic efficiency during exercise in patients with overlap of obstructive sleep apnea in metabolic syndrome
Authors: Carvalho Jefferson , Cepeda Felipe , Toschi‐Dias Edgar , Rodrigues Sara , Dutra‐Marques Akothirene , Maki‐Nunes Cristiane , Rondon Maria Urbana , Alves Maria Janiere , Braga Ana Maria , Filho Geraldo , Negrão Carlos , Trombetta Ivani
Published: June 2021

Metabolic syndrome patients (MetS) have increased cardiovascular risk in the presence of obstructive sleep apnea (OSA). Besides decreased peak oxygen consumption (VO2peak), the impairment on metabolic efficiency by linear regression (slope) of increases in VO2 and increases in workload (ΔVO2/ΔW) during submaximal exercise test can be used as a marker of worst prognosis. So, we tested the hypotheses that ΔVO2/ΔW is decreased in MetS patients and the association of MetS and OSA causes further impairment on VO2peak and ΔVO2/ΔW. Seventy eight MetS sedentary patients (ATP‐III) without the use of drugs were divided into: MetS+OSA (n=31, 49±2 yrs) and MetS‐OSA (n=30, 46±1 yrs). A control group (C; n=17, 48±2 yrs) was also studied. OSA was determined by apnea/hypopnea index (AHI>15events/h‐polysomnography). The slope ΔVO2/ΔW was determined from the 1st min up to respiratory compensation point during cardiopulmonary exercise testing.The MetS+OSA and MetS‐OSA are similar and had lower ΔVO2/ΔW (0.12±0.01, 0.13±0.01 and 0.17±0.01 ml/kg/min/W, p<0.01) and diminished VO2peak (22.6±1, 23.6±1 and 26.8±2 ml/kg/min, p<0.05) than C. ΔVO2/ΔW was associated with BMI (r=‐0,63, p<0.01), CA (r=‐0,53, p<0.01) and Glucose (r=‐0,53, p<0.01). Independently of presence of OSA, MetS patients have impaired functional capacity and metabolic efficiency during exercise. The excess body fat and insulin resistance seem to be the main causes of these decreases in MetS patients.
Four Weeks of Moderate Intensity Exercise on Levels of Cortisol, Antioxidant, and DNA Damage
Authors: Valdez Ruben , Medina Erika , Ponte Luis , Koh Yunsuk , Park Kyung‐Shin
Published: June 2021

PURPOSE

This study investigated the effects of a 4‐week moderate intensity walking exercise on levels of cortisol, antioxidant status, and 8‐OXO‐guanosine in overweight or obese individuals.

METHODS

27 physically inactive, overweight or obese individuals were randomly assigned to either exercise (N=15) or control (N=12) group. The exercise group performed moderate intensity walking exercise on a treadmill for 60 minutes at 70% of HRmax for 4 weeks (3 days/week). Overnight fasting blood samples were collected before and after the study period to analyze levels of cortisol, antioxidant status, and 8‐OXO‐guanosine. Two‐way repeated measures ANOVA and Tukey post hoc tests were used for data analysis.

RESULTS

No significant changes were found in both body weight and body composition among both groups following 4 week intervention. An increase in total antioxidant status (3.99±.15mM, Mean±SE → 4.33±.15, P=0.013) and decreases in levels of cortisol (2523.8±234.3pg/mL → 1890.7±196.2, P=.0016) and 8‐OXO‐guanosine (2078.7±138.8pg/mL → 1783.9±134.8, P=.0104) were found following 4 weeks of moderate intensity exercise; however, no significant difference were found in control group : total antioxidant status (3.99±.17 → 4.10±.17, P=.17), cortisol (2597.0±263.1 → 2482.6±219.3, P=.203), and 8‐OXO‐guanosine (1990.0±155.2 → 2021.4±150.8, P=.72).

CONCLUSIONS

The 4‐week moderate intensity exercise resulted in no change in body mass; however, it reduced the level of stress hormone and DNA damage in blood and elevated total antioxidant protection. Results indicate that 4 weeks of moderate intensity exercise may induce positive changes in endocrine system independent from changes in body weight and body composition.
Exercise Training Reduces Cardiac Dysfunction and Remodeling in Ovariectomized Rats Submitted to Myocardial Infarction.
Authors: Abreu Glaucia , Almeida Simone , Claudio Erick , Mengal Vinicius , Oliveira Suelen , Carvalho Ana Ligia , Podratz Priscila , Merlo Eduardo , Gouvêa Sônia , Graceli Jones
Published: June 2021

To evaluate the effects of exercise training (ET) on cardiac dysfunction and ventricular remodeling in ovariectomized (OVX) rats subjected to myocardial infarction (MI) and the possible mechanisms involved. OVX Wistar rats were subjected to MI or Sham surgery and divided in Control, OVX+SHAMSED, OVX+SHAMET, OVX+MISED and OVX+MIET groups. ET was performed on a treadmill (5x/wk, 60 min/day, 8 weeks). Cardiac function was assessed by ventricular catheterization and DHE fluorescence was evaluated to analyze oxidative stress. Collagen deposition, myocyte hypertrophy and infarct size was assessed by histology. Catalase, SOD‐2, Gp91phox and AT1 receptor (AT1R) expression were evaluated by western blotting. MI‐trained rats had significantly increased in +dP/dt and decreased left ventricular end‐diastolic pressure compared with MI‐sedentary rats. Moreover, oxidative stress and collagen deposition was reduced, as was myocyte hypertrophy. There were a reduction in AT1R and gp91phox expression and an increase in catalase expression. Therefore, ET improves the functional cardiac parameters and attenuates cardiac remodeling associated with a reduction in oxidative stress in OVX rats subjected to MI. Thus, ET may be an important therapeutic target for the prevention of heart failure in postmenopausal women affected by MI.
The Effect of Remote Ischemic Conditioning on Bubble Formation in a Decompression Sick Rat Model
Authors: Schmidt Nikolaj , Hansen Kasper , Pedersen Michael
Published: June 2021

Introduction

Decompression sickness (DCS) is a disabling and potentially lethal condition where bubbles nucleate from supersaturated tissues during rapid decompression. These bubbles may obstruct end arteries and thereby induce ischemia and subsequent necrosis. Remote ischemic conditioning (rIC) has been proven to attenuate ischemia‐reperfusion injuries in the brain, heart, and after kidney transplantations.

Objective

To evaluate if rIC is associated with reduced damage in rats subjected to DCS.

Method

41 female Wistar rats were randomly assigned to rIC prior to (pre‐rIC; n=10) or after (per‐rIC; n=20) pressurization. A group of sham‐dive rats (n=11) was used as control. All groups were pressurized to 6 ATA (45 min) with subsequent decompression (0.5 ATA/min). rIC was performed with a custom made tourniquet strapped around one hind leg, accomplished by a series repeated 4 times: 5 min of ischemia followed by 5 min of reperfusion. DCS was evaluated with microultrasound imaging of the pulmonary artery for 2 hrs 20 min after decompression. Two days after the experimental procedure the brains were removed and histologically examined with 2,3,5‐triphenyltetrazolium chloride (TTC) to evaluate size of brain infarcted areas.

Results

Microultrasound imaging showed no significant change in formation of nucleated bubbles in both pre‐ and per‐rIC treated groups compared to the control group. Similarly, TTC‐staining of the brain did not seem to indicate any differences between the groups.

Conclusion

The lack of reduced bubble formation and brain damage in pre‐ or per‐rIC groups indicate that the rIC procedure was insufficient to treat DCS. Future studies are required to reveal the systemic response of rIC and its possible use in DCS treatment.
Effect of simulated air dive and decompression sickness on the plasma proteome of rats
Authors: Guerrero Francois , Pichereau Vianney , Lautridou Jacky , Buzzacott Peter , Wang Qiong , Driad Sabrina , Mazur Aleksandra , Lambrechts Kate , Théron Michael
Published: June 2021

Decompression sickness (DCS) is a poorly understood systemic disease caused by inadequate desaturation following a reduction in ambient pressure. Although recent studies highlight the importance of circulating factors, the available data are still puzzling. In this study we aimed to identify proteins and biological pathways involved in the development of DCS in rats. Eighteen male Sprague‐Dawley rats were subjected to a simulated dive to 1000 kPa absolute pressure and divided into two groups: without or with clinical symptoms of DCS. A third control group remained at atmospheric pressure. Venous blood was collected one hour after hyperbaric exposure and the plasma proteomes from six individuals per group were analyzed by using a two dimensional electrophoresis based proteomic strategy. Quantitative analysis with SameSpot software identified five protein spots with abundances significantly changed (p < 0.05) between the tested conditions. Three appeared increased in DCS animals but displayed only weak changes (approx. 1.5 fold). By contrast, two protein spots dramatically decreased (i.e. quite disappeared) in animals displaying severe DCS symptoms. Identification of these proteins is currently underway using tandem mass spectrometry. This will allow for a better understanding of the molecular basis of DCS.
Impact of ATP1B4 Gene Co‐option on Perinatal Development of Placental Mammals
Authors: Modyanov Nikolai , de la Serna Ivana , Ahmad Nisar , Russo Lucia , Pestov Nikolay , Najjar Sonia
Published: June 2021

Vertebrate X‐chromosome ATP1B4 genes represent a rare instance of orthologous gene co‐option that transformed Na,K‐ATPase BetaM subunit of lower vertebrates into eutherian skeletal and cardiac muscle‐specific BetaM protein of the inner nuclear membrane. BetaM is expressed at the highest level during late fetal and early postnatal development and is implicated in the regulation of gene expression. We show that BetaM is a component of MyoD, MyoG and Smad7 transcriptional complexes in neonatal skeletal muscle and up‐regulates MyoD expression in cultured muscle cells by altering chromatin structure and recruiting SWI/SNF to the MyoD promoter.

Notably, Atp1b4 ablation in mice results in significantly lower body weight, growth retardation and high mortality of knockout neonates. Moreover,mRNA sequencing of skeletal muscle from neonatal WT and KO male littermates revealed broad changes in expression of genes important for lipid metabolism and thermoregulation as well as down regulation of fast‐twitch and up‐regulation of slow‐twitch muscle genes. These data indicate that BetaM plays an important role during a critical period of perinatal and neonatal development of placental mammals and that evolutionarily acquired new functions of BetaM proteins are physiologically essential, even might be necessary for survival of placental mammals in natural conditions, and provide an evolutionary advantage.

Supported by Dept. of Physiology & Pharmacology and Center for Diabetes and Endocrine Research, UT COM
Angiography: How to Change Clinical Anatomy Teaching to Scholarships in Education
Authors: Klinkhachorn P , Lucas J , Battin J , Klinkhachorn P
Published: June 2021

Four angiographic anatomy tutorials were developed, peer‐reviewed and published online in MedEdPORTAL of the AAMC, and made available free for global use. The objective is to change the gross anatomy teaching and its clinical application to scholarships in education. Their rationale was to stimulate active self‐directed learning by integrating clinical application into a structured format that is readily accessible for local and distance learning. The tutorials complemented learning activities of the beginner health care professionals by providing them with opportunities for self‐assessment through quizzes. Some tutorials were accessed more than 100 times in less than 10 months. Users were from six continents, i.e., North and South America, Europe, Africa, Asia, and Australia, although the majority being from the United States. Usage report data from these peer‐reviewed and published projects showed there was a total of 537 unique users from 111 countries downloading. 42% of total downloads were for teaching or training and 41% were for self‐directed learning. Others accessed them for curriculum development (12.6%), and a few used them for assessment and evaluation (4%). Local students love them because they are interactive, easy to use, have Q/A assessment and clinical application (score 4.7 out of 5, Leikert Scale). In conclusion, these teaching tools at WVU are recognized as publications, book chapters, or atlases. Authors use them as interactive learning modules for medical and dental students. Administrators evaluate them for merit adjustment, teaching awards, and for promotion and tenure purposes.
Development of Clinical Pathophysiology Lectures for Physician Assistant (PA) Students
Authors: Seaman Michael , Johnson Fruzsina
Published: June 2021

Physiology is an essential foundation of medicine, yet it is often taught with a strong emphasis on biophysics and minimal clinical references. Pathophysiology breeches this gap, but it is often neglected placing the burden primarily on the students to make the connections between basic function and clinical application. PA programs present a unique challenge, where similar breadth and depth of material is covered in half the time of medical programs providing much less opportunity for integration of knowledge. We developed lectures with the primary objective of integration of pathophysiology and clinical medicine. We chose five emergency medicine relevant topics: heart failure, respiratory failure, acute kidney injury, hypertensive urgencies/emergencies and circulatory shock; and, in close collaboration between clinician (MPS) and basic scientist (FKJ), developed comprehensive pathophysiology and medicine lecture pairs for each. All materials have been previously covered in the respective physiology and clinical medicine courses from an organ system point‐of‐view. Lecture pairs were delivered “back‐to‐back” in the pathophysiology course and were tested on the same exam using higher order pathophysiology and clinical scenario based questions. From student performance on the exam, as well as anonymous student feedback we found this approach to be highly successful. Students were not only able to solve clinical problems, but also demonstrated a strong understanding of pathophysiology, and perceived improved command of the clinical material. We feel this is an important initial step towards reforming the approach to medical physiology education.
The Effect of Rubric Delivery Method and Additional Written Comments on Future Lab Report Performance
Authors: Dawson Sierra , Wilds Gabriel
Published: June 2021

It is not uncommon to hear instructors lament the number of hours spent providing feedback on student writing, only to find their students making the very same mistake on the following assignment. The goal of this study, broadly, was to investigate how the methodology of the feedback provided to students influenced their future performance. Specifically, we investigated how students performed on their weekly 2‐page human physiology lab reports based on the inclusion or exclusion of 1‐2 sentence written comments as feedback (in addition to the grading rubric), and whether the feedback rubric was provided to the student electrically or in hard‐copy form. The subjects included students registered for a large (300 student) human physiology lecture class with an associated laboratory. Seven laboratory instructors taught the fourteen laboratory sections (2 sections per instructor). All students received feedback on their weekly 2‐page lab report using a detailed grading rubric. Each lab instructor provided one lab section with a hard copy of the rubric, while his or her other lab section viewed the rubric electronically via the online course management system's grade‐book. Half the students in every lab section received only the completed rubric (boxes checked) and half of the students also received 1‐2 sentences of written feedback. During the final week of the term, students consented to have their lab report grades included in this study, and provided a self‐assessment via an on‐line survey regarding the number of times they viewed their rubric, how they used the rubric, and their preference regarding a hard copy vs. electronic rubric. Data collection is underway and newly analyzed results will be shared.
The Drosophila Ovary as a Laboratory Model for Introducing the Genetic and Cellular Basis of Cell Migration.
Authors: Daggett Melissa , Dobens Leonard
Published: June 2021

Drosophila has been widely used in many teaching laboratories to introduce students to the practical uses of a model organism in scientific research, in particular to present and observe the outcomes of simple Mendelian inheritance. Here we present the details of a laboratory module that uses Drosophila to demonstrate the importance of gene expression in the process of cell migration. Cell migration in the Drosophila ovary is critically important for the proper morphological development of the egg chamber during oogenesis, a process that interestingly shares many of the signaling components required for cell migration observed throughout normal animal development and during tumor invasion in human cancers. This laboratory provides an opportunity to discuss the genetic and cellular basis of cell migration and to demonstrate techniques used in a modern Drosophila research laboratory including the basics of sorting males from females and identification of cuticle markers , but also the development and use of enhancer traps, balancer chromosomes, microdissection, histochemistry and microscopic analysis. Components of this laboratory module have been found to be appropriate for presentation and completion by students ranging from advanced high school laboratories through graduate level cell and developmental biology laboratory courses.