bluuebunny/crossref_metadata_2025 huggingface dataset:
Neuronal Deg/ENaC channels are targets for 4‐aminopyridine block
Authors: Boiko Nina , Kucher Volodymyr , Stockand James D.
Published: June 2021

Acid‐sensing ion channels (ASICs) are neuronal proton‐gated sodium channels that belong to the degenerin/epithelial Na+ channel (Deg/ENaC) family. Their activity is associated with a variety of complex behaviors such as fear, pain, anxiety, learning, and memory. ASICs also have been involved in neuronal degeneration during ischemia and multiple sclerosis (MS). Aminopyridines such as 4‐aminopyridine (4‐AP) are widely used as voltage‐gated K+ (Kv) channel blockers. They also have been used clinically to improve neuromuscular function in patients with spinal cord injury and multiple sclerosis. Here, we make the novel observation that 4‐AP inhibits ASIC currents native to murine hippocampal CA1 neurons and those in Drosophila polymodal, multidendritic sensory neurons. Moreover, 4‐AP inhibits recombinant ASICs and the brain liver intestine Na+ channel (BLINaC) expressed in CHO cells. This effect is dose‐dependent and a result of a decrease in conductance and not an effect on gating. The effects of compounds related to 4‐AP and amiloride support that the primary amine, which is ionized in 4‐AP, is critical to inhibition but is so only in the context of being conjugated to an organic heterocyclic ring. These results suggest that perhaps the beneficial effects of 4‐AP on MS are a manifestation of inhibition ASIC channels in parallel with inhibition of Kv channels.
Epithelial Ion Channel Function Altered by Influenza A Induced Cytokine Production
Authors: Waugh Taryn A. , Ching John C.H. , Glew Riley A. , Zhou Yan , Loewen Matthew E.
Published: June 2021

Influenza A infection of respiratory airway epithelium produces cytokines that aid in fighting the infection. However, the excessive increase in cytokine production during severe influenza infections could contribute to altered airway ion channel activity that disrupts the airway fluid balance leading to pulmonary edema. Using qRT‐PCR and Bio‐Plex array we measured cytokines in Calu‐3 cells infected with influenza A. We simultaneously measured channel function by means of short‐circuit current produced by a Calu‐3 monolayer in response to agonists and channel blockers. Viral protein production and initial increases in cytokines were found at 24 hours post infection. Interestingly, no change in short‐circuit current response was found. However, further increases in proinflammatory cytokines at 48 hours post infection, such as IL‐8 and IL‐6, did correlate with a change in the agonist induced short‐circuit current response. However, the observed decreases in cAMP induced short‐circuit current, did not correlate with the significant increases in CFTR mRNA. In conclusion, influenza infection either directly or in concert with cytokines can induce transcriptional expression of ion channels but simultaneously inhibit their function. This study helps understand the pathophysiology which drives fluid into the lungs during an influenza A infection. Support: SHRF, EHRF, CAHF, CFI and NSERC
Endothelial progenitor cells in pulmonary arterial hypertension
Authors: Loehr Jeremy E , Tremblay Eve , Blanchet Marie‐Renée , Bonnet Sébastien , Provencher Steeve
Published: June 2021

Objective

Pulmonary arterial hypertension (PAH) is a vascular disease characterized by distal pulmonary arteries remodeling, caused by an increase in pulmonary arterial smooth muscle cells (PASMC) proliferation and apoptosis resistant. The activation of transcription factors HIF‐1α and NFAT maintain this phenotype. Studies have shown implications of endothelial progenitor cells (EPC) in angiogenesis by their capacity to infiltrate the vascular wall and to secrete vasoactive factors.

Hypothesis: EPC are at the origin of the activation of HIF‐1α and NFAT thus vascular remodeling in PAH.

Methods/Results

EPC were isolated by FACS (CD34+CD45dim) from the buffy coat of 6 patients (3 ctrl; 3 PAH). The EPC were placed in a Boyden chamber on top of healthy human PASMC. EPC secretion factors are able to diffuse freely and interact with the healthy PASMC since a 0.4 μm membrane separates them. After 48 hours, we observed by fluorescence an increased proliferation (Ki67, p<0.05; FLUO3‐AM, p<0.05) and apoptosis‐resistance (TUNEL, p<0.05; TMRM, p<0.05; MitoSOX, p<0.05) of PAH‐EPC compared to ctrl‐EPC stimulated PASMC. The activation of HIF‐1α (p<0.05) and NFAT (p<0.05) collaborate the phenotype. These observations are reinforced by in vivo results showing a resistance to monocrotaline pyrrole‐induced PAH in CD34 KO mice.

Conclusion

We show that EPC are implicated in the etiology of PAH by their secretion factors that render the PAH phenotype in healthy PASMC.
PP2A activation is required for lipid‐induced arterial dysfunction in mice
Authors: Nhan Jennifer , Panneerseelan Leena , Ruan Ting , Wan Xin , Johnson Elizabeth , Li Youyou , Zhang Quan‐Jiang , Abel E Dale , Symons J David
Published: June 2021

We hypothesized that PP2A activation is required for lipid‐induced, ceramide‐mediated arterial dysfunction. Mice haploinsufficient for dihydroceramide desaturase (des1+/−) and their wild‐type littermates (des1+/+) were infused (iv) for 6 h with lard‐oil (LO) or vehicle (veh). Subgroups of LO and veh mice were treated (1.5 mg/kg IP) for 3 days prior to infusion with the PP2A inhibitor LB1 (Lixte Biotechnology, NY). LO increased ceramide accrual in arteries from des1+/+ but not des1+/− mice. Palmitate (3 h × 500 uM) increased (p<0.05) PP2A activity, and impaired (p<0.05) insulin‐stimulated p‐eNOS(S)1177 to eNOS in endothelial cells, and these responses were negated by LB1 (4 uM; n=5–8). Endothelium‐dependent and –independent relaxation of femoral arteries (~ 150 um i.d.) was assessed using acetylcholine (ACh) and sodium nitroprusside (SNP), respectively (n=3 mice/group, 3 vessels/mouse). ACh‐mediated (2×10−8, 3×10−8, and 6×10−8 M) relaxation (%) was less (p<0.05) in LO des1+/+ (30±2, 41±3, and 61±4, respectively) vs. veh des1+/+ mice (48±4, 67±6, and 73±6, respectively). Endothelial dysfunction observed in LO des1+/+ mice was less severe when ceramide accrual (i.e. LO des1+/− mice) or PP2A activation (i.e., LB1 + LO des1+/+ mice) were prevented. SNP‐evoked vasorelaxation was intact among groups. LO‐induced ceramide accumulation induces endothelial dysfunction that is dependent upon PP2A activation. ADA1–12‐ BS‐208, 2R15HL091493
NLRP3 Inflammasome is activated in the kidneys of Metabolic Syndrome animals
Authors: Nair Anand R. , Wilson Brad , Francis Joseph
Published: June 2021

Inflammasomes are oligomeric protein complexes formed in response to Danger‐associated molecular patterns (DAMPS) such as uric acid crystals and asbestos and have been shown to contribute to the pathogenesis of metabolic syndrome (MetS). Since uric acid is increased in chronic kidney disease, we hypothesized that increase uric acid might induce NLRP3 inflammasomes and exacerbate MetS via disrupting the redox balance and causing structural and functional impairment of the kidneys. Male Lean zucker controls (LZR) and Obese (OZR) underwent acute renal clearance and hemodynamic study. Compared to the OZR rats, the LZR exhibited higher glomerular filtration rate, higher renal blood flow and lower renal vascular resistance. Renal histopathology results revealed glomerulosclerosis, interstitial nephritis and proteinuria, and Real time RT PCR showed an increased gene expression of kidney injury markers and inflammasomes in OZR rats. Free radical production rates measured by electron paramagnetic spectroscopy showed a reduced total reactive oxygen species, superoxide and peroxynitrite levels in LZR animals. The gene and protein expression levels of IL‐1β and IL‐18 were higher in OZR rats. The plasma uric acid levels were higher in OZR rats. Our results indicate that inflammasomes are activated in the kidneys of MetS, thereby contributing to increased oxidative stress and renal damage. Research supported by LSU.
INVOLVEMENT OF NITRIC OXIDE AND REACTIVE OXYGEN SPECIES IN CARDIOVASCULAR DISFUNCTION OF RATS WITH OBESITY INDUCED BY MONOSODIUM GLUTAMATE
Authors: Martins‐Pinge Marli , Cunha Natália Veronez , Pinge‐Filho Phileno , Bendhack Lusiane Maria
Published: June 2021

We investigate the involvement of nitric oxide (NO) and reactive oxygen species (ROS) on autonomic, cardiovascular parameters and endothelial cells isolated from aorta in monosodium glutamate (MSG) obese rats. Obesity was induced by administration of 4 mg/g body weight of MSG or equimolar saline (CTR) in newborn rats. At 60th day, treatment was started with L‐NAME (20 mg/kg) or 0.9% saline. At 90th day, artery catheterization was done and after 24 hours, mean arterial pressure (MAP) and heart rate (HR) were recorded. Plasma was collected to assess lipid peroxidation. Endothelial cells were evaluated by flow cytometry and fluorescence intensity (FI) emitted by NO‐sensitive dye (DAF‐2DA) and sensitive to ROS (DHE). MSG is hypertensive compared to CTR. Treatment with L‐NAME increased MAP only in CTR. The MSG induced increase in LF band and decrease in HF band of heart rate variability. The treatment with L‐NAME increased LF band of SAP in CTR without changes in MSG. Lipid peroxidation was higher in MSG and attenuated after L‐NAME. Basal FI to DAF was higher in CTR than MSG. Both groups, acetylcholine increased IF for DAF from basal. However, those values were lower in MSG than CTR. IF baseline to DHE was higher in MSG than CTR. Acetylcholine increased FI to DHE, but this effect was lower in CTR than MSG. We suggest that lower NO bioavailability and increased production of ROS may contribute to elevated blood pressure in MSG animals.
The potential role of caveolin in intracellular signaling for cardiac protection of (−)‐epigallocatechin‐3‐gallate
Authors: Liou Ying‐Ming , Hsieh Shih‐Ron , Hsu Chen‐Sen
Published: June 2021

In this study, we showed the putative mechanism for the cardio‐protection of (−)‐epigallocatechin‐3‐gallate (EGCg). H9c2 cardiac myoblasts exposed to H2O2 decreased cell viability by increasing reactive oxygen species and cytosolic Ca2+, and imposed cell cycle arrest at G1‐S phase via the signaling pathway for glycogen synthase kinase‐3β/β‐catenin/cyclin D1. All these H2O2‐induced cardiac cell injuries could be counteracted by EGCg pretreatment. To determine the binding of EGCg to H9c2 cells, EGFP (enhanced green fluorescence protein) was ectopically expressed in the cells. In overexpressed cells EGFP formed the protein complexes with 67 kD laminin receptor, caveolin‐1 and ‐3, γ‐actin, myosin IX, and vimentin. EGFP fluorescence measurements showed that EGCg bound to intact, Triton X‐100 soluble fraction, and Triton X‐100 insoluble fraction of H9c2 cells with a dissociation constant (Kd) of ~ 86, ~126, and ~42 μM, respectively. H9c2 cells pretreated with H2O2 increased the binding affinity of EGCg (Kd = 47μM). Using a rat model of myocardial infarction involving left anterior descending coronary artery ligation we showed involvement of caveolin‐3 in the cardio‐protection of green tea polyphenols against myocardial ischemia. Taken together, caveolins might serve as rafts for intracellular signaling to mediate cardiac protection of EGCg.
Inhaled nitric oxide attenuates the adverse effects of transfusing stored red blood cells in mice with endothelial dysfunction after hemorrhagic shock
Authors: Yu Binglan , Lei Chong , Shahid Mohd , Beloiartsev Arkadi , Bloch Kenneth D , Zapol Warren M
Published: June 2021

Background

Transfusion of red blood cells (RBCs) stored for prolonged periods is associated in some retrospective studies with adverse clinic outcomes in patients. We investigated whether transfusion with stored RBCs would increase tissue injury, inflammation, oxidative stress and mortality (adverse effects of transfusing stored RBCs) in a murine model of hemorrhagic shock. We tested whether the adverse effects associated with transfusing stored RBCs were exacerbated by endothelial dysfunction and ameliorated by inhaling nitric oxide.

Methods

We studied mice fed a high‐fat diet (HFD‐fed, to induce endothelial dysfunction) or a standard diet for 4–6 weeks. Mice were subjected to 90 min of hemorrhagic shock, followed by resuscitation with leukoreduced syngeneic RBCs stored for less than 24 h (fresh RBCs) or stored for 2 weeks (stored RBCs).

Results

In standard diet‐fed mice at 2 h after resuscitation, transfusion with stored RBCs increased tissue injury more than transfusion with fresh RBCs. The adverse effects of transfusing stored RBCs were more marked in HFD‐fed mice and associated with increased lactate levels and short‐term mortality. Compared with fresh RBCs, resuscitation with stored RBCs was associated with a reduction in P50, increased plasma hemoglobin levels, and increased indices of inflammation and oxidative stress, effects that were exacerbated in HFD‐fed mice. Inhaled nitric oxide reduced tissue injury, lactate levels, and indices of inflammation and oxidative stress, as well as improved short‐term survival in HFD‐fed mice resuscitated with stored RBCs.

Conclusions

Resuscitation with stored RBCs adversely impacts outcome in mice with hemorrhagic shock, an effect which is exacerbated in mice with endothelial dysfunction. Inhaled nitric oxide reduces tissue injury and improves short‐term survival in HFD‐fed mice resuscitated with stored RBCs.
INSULIN‐INDUCED AUGMENTATION OF CREMASTER MUSCLE INTRACAPILLARY BLOOD VOLUME IS IMPAIRED IN DB/DB MICE
Authors: VanTeeffelen Jurgen Willem , Vink Hans , Eskens Bart
Published: June 2021

Insulin sensitivity has been related to insulin's ability to increase capillary blood volume in skeletal muscle. Based on our previous studies indicating that agonists augment intracapillary blood volume by increasing blood access into the endothelial glycocalyx, we hypothesize that insulin increases blood volume within individual capillaries in muscle of healthy mice, but not of diabetic mice with manifested glycocalyx damage. Intravital microscopy of cremaster muscle was performed in anesthetized C57Bl/6 (CON, n=5) and db/db mice (DB, n=5). Capillary hemodynamics (red blood cell flux & velocity, anatomic diameter) were monitored at baseline and during insulin administration to the superfusate (20 – 200 μU/ml). Capillary tube hematocrit (Hcap) was calculated as measure of functionally perfused capillary blood volume. In CON, Hcap was 0.093 ± 0.008 (SEM, n=25 capillaries) at baseline; insulin increased (P<0.05) Hcap to 0.143 ± 0.011 (20 μU/ml) and 0.0139 ± 0.008 (200 μU/ml). In DB, baseline Hcap was already elevated (0.154 ± 0.01, n=36 capillaries); insulin administration resulted in stagnant RBCs in 44% of the examined capillaries while in the remaining Hcap did not change. Our results indicate that the insulin‐induced increase of capillary blood volume in muscle involves a glycocalyx‐dependent volume increase in individual capillaries rather than recruitment of additional capillaries.
Genetic interference with peroxisome proliferator‐activated receptor γ (PPARγ) in smooth muscle enhances cerebrovascular myogenic tone via a rho kinase‐dependent mechanism
Authors: De Silva Michael , Ketsawatsomkron Pimonrat , Pelham Christopher , Sigmund Curt D , Faraci Frank M
Published: June 2021

Cerebral arteries are important resistance vessels and play a crucial role in regulating cerebral blood flow (CBF). Myogenic responses are a key element of mechanisms that regulate CBF during altered perfusion pressure. PPARγ may play a protective role in the vasculature by inhibiting increases in vascular tone. We tested whether cell‐specific interference with PPARγ in smooth muscle would increase myogenic tone in cerebral arteries. We studied mice expressing a dominant negative mutation of human PPARγ in smooth muscle (TG) and littermate controls (NT). Under baseline conditions (75 mmHg), middle cerebral arteries (MCA) from TG mice generated more myogenic tone compared with arteries from NT (31±4% vs. 9±2% of max diameter n=7–8). Myogenic reactivity was augmented in MCA from TG mice over a range of pressures (15–150 mmHg) compared with NT whereas diameter in Ca2+ free conditions was similar between groups. Treatment of MCA from TG mice with the rho kinase inhibitor Y27632 abolished the augmentation of myogenic tone (34±5% vs. 9±4% of max diameter n=7). Treatment of vessels from TG with the superoxide dismutase mimetic tempol reduced myogenic tone by ~30% (33±4% vs. 21±2% of max diameter n=6). These findings suggest that PPARγ in vascular muscle regulates rho kinase, influencing myogenic tone in small resistance arteries. This work was supported by NIH grants NS24621 and HL62984 and AHA Fellowship 12POST9150027.
Aerobic Training (T) Improves Microcirculatory Profile in Brain Areas of Normotensive (WKY) and Spontaneously Hypertensive Rats (SHR)
Authors: Jordão Maria Tereza , Cavalleri Marina Tuppy , Burgi Katia , El Chaar Laiali Jurdi , Ceroni Alexandre , Michelini Lisete Compagno
Published: June 2021

To evaluate the effects of hypertension and T in the microcirculatory profile within autonomic areas, WKY and SHR were submitted to treadmill T (55% of maximum capacity, 1h/day, 5 d/week) or kept sedentary (S) for 3 months. After hemodynamic measurements at rest, rats were anesthetized for FITC‐dextran administration (1 ml of 5% solution). Brains were removed, post‐fixed and sliced (25 μm) for analysis of the capillary volume (Image ProPlus + 3D‐construction) within the NTS and hypothalamic paraventricular nucleus (PVN). SHR vs. WKY exhibited elevated MAP and HR (180±2 mmHg, 359±6 b/min). Capillary volume (expressed as ×10−3μm3/μm3 tissue) was similar in WKY‐S and SHR‐S but differed between autonomic areas being larger into the PVN (ventromedial=14.15±1.27, posterior=6.72±0.56) and smaller into the NTS (2.51±0.14). T improved treadmill performance and resting bradycardia (−9%) in both groups; pressure fall (−8%) was only observed in the SHR. T caused marked increase in capillary volume in all autonomic areas (ventromedial: +91% and +74%; posterior: +20% and +21%; NTS: +41% and +27%, for WKY and SHR respectively). Contrary to the peripheral microcirculatory response, hypertensive brain capillaries showed no rarefaction within autonomic areas. Data also showed a large T‐induced capillary angiogenesis in both groups, therefore improving brain perfusion after training. Financial Support: CAPES, FAPESP
Enhancement of a model of essential tremor using SNNAP
Authors: Moran Joseph , Watrous James
Published: June 2021

Essential tremor (ET) is a disorder characterized by uncontrollable shaking in the extremities. The exact cause is unknown; thus, ET is currently the focus of several investigators. The focus of this research is the development of an improved computer model of ET. SNNAP (Simulator for Neural Networks and Action Potentials) was used to construct a model motor circuit. The initial network and neuron construction is based on work done by Shaikh et al., 2008. The model neuron is a Hodgkin‐Huxley type with additional hyperpolarizing and low threshold Calcium currents. The network contains eight neurons arranged in a simplified motor circuit. A muscle cell (20 μm × 200 μm) was inserted into the network as the output cell, providing a more physiologically realistic model. The benefits of the network have proven to be the ability to analyze the behavior of each cell and synaptic connection individually. Our results identify the hyperpolarizing channel and the conductance of synaptic connections as being most influential in controlling frequency of tremors while the sodium channel is most influential in controlling amplitude.
Small peptide PEP7 can decease Angiotensin II (Ang II) induced function through MAPK signaling pathway
Authors: Liu Jun , Zhang Dan , Ji Hong , Bajaj Bilkish , Zheng Wei , Samson Willis , Sandberg Kathryn
Published: June 2021

Sequence analysis of the 5′ leader sequence (5'LS) of the rat angiotensin type 1a receptor (rAT1aR) mRNA revealed a short open reading frame (sORF) within exon 2 (E2) which is in frame with the downstream major open reading frame that encodes the AT1aR. We found that the 7 amino acid peptide (PEP7) encoded by this sORF decreased 125I‐[Sar1, Ile8]Ang II specific binding by 23% in transfected human embryonic kidney‐293 (HEK‐293) cells expressing the rAT1aR under conditions in which the scrambled PEP7 (sPEP7) did not [dpm/μg protein: Vehicle, 162.2 ± 8.2, PEP7, 125.7 ± 7.0, sPEP7, 179.9 ± 3.9; n=3]. Furthermore, PEP7 inhibited angiotensin II (Ang II)‐induced activation of extracellular signal‐regulated kinases 1 and 2 (ERK1/2) – defined as the phosphorylation of ERK1/2 (pERK1/2) with respect to total ERK1/2 (pERK/ERK) expression (measured by Western blot) in a dose‐ and time‐dependent manner. Ang II (100 nM) rapidly caused phosphorylation of ERK1/2, which was maximum after a 5 min exposure. Incubation of these cells with 2.5 μM PEP7 3 hours prior to Ang II stimulation for 5 min inhibited pERK1/2 generation by 62% [pERK1/2/ERK1/2 (AU): Ang II, 1.000 ± 0.0, Ang II+PEP7, 0.3812 ± 0.086, Ang II+sPEP7, 1.069 ± 0.18; n=2–3]. The inhibitory effect of PEP7 was not instantaneous since incubation of PEP7 20 min prior to stimulation with Ang II was without effect. Our findings suggest that PEP7 plays a regulatory role in controlling the expression and activity of the rAT1aR. [Supported by R01‐HL59502 (KS) and R01–066023 (WKS)]
Developmental change in neuromast distribution in the anterior lateral line of muskellunge (Esox masquinongy)
Authors: Helwig Christin , Robertson John
Published: June 2021

The lateral line system of teleost fish is comprised of individual sensory elements, neuromasts, which together form a mechanosensory system. Because neuromasts have been studied in relatively few species, the biology of the lateral line in diverse taxa of fishes remains an open area of inquiry. Musky are predatory fish native to central North America; these prized game fish have been extensively propagated and introduced to many locations. This study investigated the development of neuromasts in the anterior lateral line system of muskellunge. I hypothesized that as juvenile muskellunge grow, the number of neuromasts in the anterior lateral line would increase. Live staining with DASPEI, fluorescence microscopy and image analysis were used to determine the number and spatial distribution of head neuromasts in developing muskellunge. Results indicate that the number of head neuromasts increases over early development; specifically, neuromast number increases in the pre‐orbital line, a sub‐region of the anterior lateral line. This change was further determined to occur via increased neuromast density, as opposed to elongation of the preorbital line. These findings contribute specifically to understanding of muskellunge sensory biology and generally to development of the lateral line system. This work was supported by Westminster College's Drinko Center for Experiential Learning.
Activation of xanthine oxidase mediates intermittent hypoxia‐induced HIF‐2 degradation
Authors: Nanduri Jayasri , Khan Shakil A , Wang Ning , Vaddi Damodara R , Makerenko Vladislav , Nanduri Prabhakar R
Published: June 2021

We previously showed that IH leads to increased degradation of HIF‐2α via [Ca2+]i activated calpains, which contributes to IH‐induced oxidative stress via insufficient transcription of antioxidant enzymes (J. Nanduri et al. PNAS, 2009). In this study, we examined the mechanisms associated with activation of calpains by IH in PC12 cell cultures. In IH treated PC12 cells, ROS levels as well as calpain activity increased and anti‐oxidant treatment prevented these effects suggesting the involvement of ROS signaling. Pharmacological or genetic blockade of NADPH oxidase 2 (Nox2) had no effect on IH‐evoked calpain activation and HIF‐2α degradation. However, IH markedly increased xanthine oxidase (XO) activity. Allopurinol, a XO inhibitor or silencing of XO by siRNA prevented IH induced HIF‐2α degradation, increased intracellular calcium levels and calpain activity. Systemic adminsitration of allopurinol to rats during the IH exposure prevented the oxidative stress, rescued HIF‐2α degradation in the adrenal medulla and prevented hypertension. These results demonstrate that ROS generated by XO activation mediates IH‐induced HIF‐2α down regulation and suggest that ROS‐induced ROS as a potential mechanism contributing to IH‐induced cardiovascular morbidity.
Is functional sympatholysis (FS) altered in chronically hypoxic (CH) rats?
Authors: Ray Clare J , Wallice Rachel , Cook Rosalind , Coney Andrew
Published: June 2021

Muscle sympathetic vasoconstriction is blunted in CH, however, there is no change in the modulatory role of NO. Exercise intolerance and CH are features of diseases such as COPD, this may reflect alterations in FS and fatigability. In accordance with UK legislation, experiments were performed on anaesthetised CH rats (3 weeks acclimation to 12% O2). Lumbar sympathetic chain stimulation was used to induce sympathetic vasoconstriction. Peroneal nerve stimulation evoked EDL contraction and tension was recorded. Femoral vascular resistance was calculated from recordings of arterial blood pressure and femoral blood flow. Sympathetic vasoconstriction was evoked during baseline and graded muscle contraction (10–30% max twitch) under control conditions, after NOS inhibition (L‐NAME) and again following restoration of background NO levels (SNP infusion). Compared to normal (N) rats, peak muscle tension was not different but CH rats fatigued more such that plateau tension was lower (even when O2 delivery was similar to N rats). FS was not different in CH and N rats and was not affected by either L‐NAME or SNP infusion. Muscle fatigue is greater in CH than N rats but it is not due to differences in O2 delivery. FS is unchanged despite sympathetic vasoconstriction being blunted in CH rats, and there appears to be no role for NO in mediating FS. Changes in FS are unlikely to explain exercise intolerance in diseases such as COPD.
Chronic coffee consumption alters gut microbiome: potential mechanism to explain the protective effects of coffee on type 2 diabetes?
Authors: Cowan Theresa E , Palmnas Marie , Ardell Kendra , Yang Jaeun Jane , Reimer Raylene , Vogel Hans , Shearer Jane
Published: June 2021

Cumulative epidemiological studies indicate a negative relationship between coffee consumption and type 2 diabetes (T2D). However, the specific mechanisms by which coffee reduces T2D is unknown but may involve the metabolism of polyphenols in coffee by the gut microbiome. To this end, we examined the impact of chronic coffee consumption on the gut microbiome in lean and diet‐induced obese rats. Male Sprague‐Dawley rats (n=40) were randomized into chow (CH, 12% kcal fat) or high fat (HF, 60% kcal fat) dietary groups. Each group was further divided into groups consuming water or coffee for 8wk, consuming food and fluid ad libitum (n=10/treatment). Coffee consumption was associated with lower weight gain and body fat percentage in both CH and HF (p<0.05). Oral glucose and insulin tolerance tests showed HF (p<0.05) but not coffee consumption to alter insulin action. Compared to CH, HF resulted in a reduction in Total Eubacteria levels in water but not coffee treatment (p<0.05). Lactobacillus was decreased in the HF‐water group but not HF‐coffee suggesting coffee had a protective effect. Alterations in the gut microbiome were supported by analysis of serum metabolites by proton nuclear magnetic resonance spectroscopy (1H NMR) and gas chromatography mass spectrometry (GC‐MS). This data indicate that gut microbiota‐host metabolic interactions may mediate the beneficial effects of coffee on the development of T2D.
Medical students perceptions of ultrasound use for Gross Anatomy teaching by clinicians and anatomists
Authors: Jurjus Rosalyn A , Dimorier Kathryn , Brown Kirsten , Slaby Frank , Calabrese Kathleen , Liu Yiju Teresa
Published: June 2021

The utilization of bedside ultrasound by an increasing number of medical specialties has created the need for more ultrasound exposure and teaching at the medical student level. Although, there is a widespread support for more vertical integration of ultrasound teaching throughout the undergraduate curriculum, little is known about whether the quality of ultrasound teaching differs if performed by anatomists or clinicians. The purpose of this study is to evaluate medical students’ perceptions of ultrasound anatomy teaching by clinicians and anatomists.

Hands‐on interactive ultrasound sessions were scheduled as part of the Gross Anatomy course following principles of adult learning and instructional design. Seven teachers (3 anatomists and 4 clinicians) taught in each session. Prior to each session, anatomists were trained in ultrasound by clinicians. Students were divided into groups, rotated teachers between sessions, and completed evaluations.

Preliminary data demonstrates a slight, although non‐statistically significant preference of the students to the clinicians’ teaching, suggesting that with minimal training, anatomists are as facile at teaching ultrasound anatomy as clinicians. This study will allow medical educators to assess ultrasound teaching by both anatomists and clinicians, and encourage the assimilation of hands‐on ultrasound into human anatomy courses.

Grant Funding Source: None
Combining E‐learning With Practical Anatomy ‐ A New Dissection Manual
Authors: Hirtler Lena , Zauleck Max , Streicher Johannes
Published: June 2021

Introduction

Benefiting from the new technical possibilities concerning computer hard‐ and software and following the trend of e‐learning as well as blended‐learning, a new instruction manual for anatomical dissection courses was developed.

Method and Design

The documents were created with Adobe© InDesign© CS5.5 software. Each manual contains information on corresponding textbook chapters for reference as well as hyperlinks connecting dissectional photos and sketches to the text. In the photos, relevant structures were numbered. Moving the mouse over the number activates a “roll‐over”‐link revealing the correct name of the structure. In addition, together with the respective dissection protocol corresponding clinical learning objectives are listed and hyperlinks to dissection protocol‐corresponding clinical learning objectives as well as hyperlinks to videos of clinical procedures and visualizations of developmental key‐processes are provided.

Outlook

This learning material follows the general trend of “blended learning”, which has also already demonstrated some benefits in teaching anatomy. By clinical connections and detailed photo‐documentation, the application will not be limited only to medical students, but could also provide for anatomical recapitulation in postgraduate training.

Grant Funding Source: n/a
Multi modal Virtual Anatomy Learning Tools for Medical Education using recent advances in IT
Authors: Ponnampalam Gopalakrishnakone
Published: June 2021

Computer‐aided learning (CAL) has great potential in facilitating learning. In medical education, several approaches using CAL have been used. In this paper, we present a software platform human anatomy which we designed to provide a virtual learning environment to support teaching and learning delivered on a workstation, mobile devices as well as multi touch screens. The virtual 3D environment is particularly useful for medical students to identify key anatomy structures and their complex spatial relationships.

Modeling and direct volume rendering (DVR) technologies are applied to anonymized actual patients’ CT Data. The intuitive computer graphic interface and virtual reality 3D environment make learning interesting and engaging. The platform also allows instructors to easily customize the anatomy model by adding additional digital supplementary learning material, including hyperlinks, additional images, animation, audio, video and PowerPoint presentations which are all supported within the learning environment. To make use of online and mobile learning Function, the system provides interface to extend online and mobile learning. The prototype has been evaluated by medical students and teaching staff for further refinements.
Dissection, prosection or both in teaching medical gross anatomy: An old question revisited
Authors: Vasan Cheryl , Pinhal‐Enfield Grace , DeFouw David , Vasan Nagaswami
Published: June 2021

Thorough knowledge and understanding of human body which is foundation to medicine, partly comes from dissection. Dissection helps develop anatomical knowledge, value 3‐D relationships and normal variation, mental mapping for integration, motor skill and promotes empathy and professionalism. Now in medical education, the role of dissection is questioned and reevaluated due to diminished curriculum time, cost and availability of alternate teaching tools. In US, while no school has completely eliminated dissection many have included prosection and other teaching aids to teach anatomy. There is no definite answer to the superiority of one approach over the other. Often prosections are peer taught. In 2010 as part of TBL pedagogy, we adopted prosections to teach head and neck anatomy to medical students. In contrast to peer teaching, our small group teaching is faculty led for a period of 4 weeks with 2–3 case based discussion sessions. Students’ received focused study guide and periodic quizzes with immediate feedback. We evaluated the effectiveness of this approach analyzing students’ exam performance and course evaluation. Students performed as well or slightly better than the classes who dissected head and neck. Better performance could be due to more available study time and faculty led small group teaching. Analysis of the results and our approach will be detailed in the presentation.
The relationship between in‐class written exercise and exam performance in an allied health gross anatomy course
Authors: Warren Kelly M
Published: June 2021

Interactive teaching methods, such as in‐class written exercises, can be added to traditional lectures to assess and enhance student learning. The goal of this study was to determine if student performance on in‐class written exercises could be used to predict exam performance. A set of identical written exercises, consisting of 5–6 questions, was administered to 45 allied health graduate students immediately before (PRE) and after (POST) three review lectures in a gross anatomy course. Students were given the correct answers to the questions after completing the POST exercise. For all three blocks, student performance increased significantly between PRE and POST exercises, suggesting short term knowledge acquisition. PRE scores were positively correlated with block exam scores (1:r2=0.29, 2:r2=0.16, 3:r2=0.11; p<0.05), while POST scores only showed a significant positive correlation with the first and second block exam scores (1:r2=0.14, 2:r2=0.23; p<0.05). Student feedback indicated that exercises enhanced the learning experience and subject matter understanding. Our findings suggest that a moderate positive correlation exists between PRE/POST exercise and exam performance, although not uniform in nature. While in‐class exercise performance may not be a strong predictor for exam performance, exercises can be used to enhance student learning and self‐assessment in traditional lecture formats.

Grant Funding Source: n/a
Horizontal and Vertical Integration of Basic Sciences within the Undergraduate Medical Curriculum: Development of High Yield Modules for Contextual Learning
Authors: Poznanski Ann , Niculescu Iuliana , Gould Doug , Hankin Mark
Published: June 2021

Opportunities to integrate basic and clinical sciences are present throughout undergraduate medical education; we have developed innovative approaches that lead to vertical and horizontal integration within our curriculum. High‐yield modules that involve presentation by multi‐disciplinary teams explore foundational concepts introduced in preclinical years, but are perhaps best valued and applied after encounters with patients. Examples include: hematologic malignancies; stroke syndromes; vasculitides; clinical anatomy review for ER procedures; and congenital anomalies. Such contextual, integrative learning has benefits for students, including: improved understanding of biological principles and pathophysiological mechanisms; increased motivation and satisfaction; and enhanced self‐appraisal and self‐efficacy. Benefits for presenters include: professional socialization; enhanced reflection by clinicians and basic scientists on the scientific basis of medical practice and clinical applications of research. Effectiveness of the integration will be evaluated by: 1) end of year focus groups; 2) student satisfaction surveys; and 3) long‐term, longitudinal evaluation of course and board performance.
“Safe Harbor” Forum: Professionalism Reflection Sessions for First Year Medical Students in the Gross Anatomy Course
Authors: Spampinato Christine , Wittich Christopher , Pawlina Wojciech
Published: June 2021

Use of reflection in medical education has been shown to enhance health care practitioner competency and enable a transformation from passive learning of theoretical constructs to a more active acquisition of core competences. Implementation of reflection in medical curriculum is a challenge, and a deficiency of reflective practice has been noted by residency directors. This highlights a need to develop reflective skills within the medical curriculum. In the anatomy course, reflection facilitates deeper learning and gives meaning to a student's dissection experience. During the 7 week gross anatomy course, we implemented four reflection sessions (“Safe Harbor”) aimed at fostering reflective capacity through encouraging student reflection on elements of professionalism including teamwork, ethics, and work‐life balance. Approximately two‐thirds of the class voluntarily participated in sessions lead by near‐peer facilitators. Reflection in professionalism index scores were analyzed at the beginning and end of the course. Preliminary results suggest first year students appreciate the “Safe Harbor” forum to reflect on anatomy course experience, professionalism, and personal challenges. Facilitators report positively on students personally adopting and integrating the reflection framework during Safe Harbor sessions, thereby suggesting an increased capacity to reflect on professionalism.

Grant Funding Source: Dept of Anatomy, Mayo Clinic, Rochester, MN
Mutations disrupting PI3K signaling act as dominant enhancers of ethanol teratogenicity
Authors: McCarthy Neil , Wetherill Leah , Ben Lovely C. , Swartz Mary E. , Foroud Tatiana M. , Eberhart Johann K.
Published: June 2021

Fetal Alcohol Spectrum Disorder (FASD) is one of the most prevalent human birth defect and a commonly effected organ is the craniofacial skeleton. The variability of defects found in FASD patients suggests an underlying genetic predisposition. In a genetic screen for ethanol susceptibility loci, we found that platelet‐derived growth factor receptor alpha (pdgfra) interacted synergistically with ethanol during zebrafish craniofacial development. Analysis of a human dataset also shows an interaction between PDGFRA and ethanol, prompting a mechanistic understanding of this interaction. Craniofacial defects in ethanol‐treated pdgfra mutants and heterozygotes appear to be due to increased apoptosis, a defect not present in untreated pdgfra mutants. Blocking PI3K/AKT signaling in pdgfra mutants recapitulates the ethanol‐induced defects and increasing PI3K signaling rescues the ethanol‐induced defects in pdgfra mutants. This mechanism predicts that other PI3K‐dependent signaling pathways would be ethanol sensitive. Indeed, insulin receptor alpha and connective tissue growth factor interact with ethanol to generate a different set of craniofacial defects. We propose a model where the combined genetic and environmental inhibition of PI3K signaling causes variability within FASD.
MicroRNA‐26b Represses Colon Cancer Cell Proliferation by Inhibiting Lymphoid Enhancer Factor 1 (LEF‐1) Expression
Authors: Sun Zhao , Zhang Zichao , Li Xiao , Amendt Brad
Published: June 2021

microRNAs can act as oncogenes and tumor suppressors and miR‐26b is down regulated in several cancers and tumors. We have previously reported that miR‐26b directly targets the Lef‐1 3'UTR and inhibits endogenous Lef‐1 expression. miR‐26b expression is associated with human colon cancer through the regulation of LEF‐1 expression in colon cancer cells. Analyses of multiple colon cancer cell lines revealed an inverse correlation between miR‐26b and LEF‐1 expression. Normal human colon cells express low levels of LEF‐1 and high levels of miR‐26b, however human colon cancer cells have decreased miR‐26b expression and increased LEF‐1 expression. We demonstrate that miR‐26b has a potent inhibitory effect on colon cancer cell proliferation. Endogenous LEF‐1 expression was significantly decreased by miR‐26b over expression. The Wnt/β‐catenin target genes cyclin D1 and c‐MYC were also repressed resulting in reduced cell proliferation. Furthermore, miR‐26b inhibits the growth of SW480 colon cancer cells in mice xenograft experiments. c‐MYC expression is associated with multiple cancers and we propose miR‐26b may act as a potential therapeutic agent in reducing cancer cell proliferation through repressing LEF‐1 activation of c‐MYC and cyclin D1 expression.
Evaluation of Oxidative DNA Damage, Lipid Peroxidation and Antioxidant Status in Patients Undergoing Surgery with Sevoflurane Anesthesia
Authors: Braz Mariana Gobbo , Orosz José Eduardo B , Pierine Damiana T , Braz Leandro G , Ferreira Ana Lúcia A , Salvadori Daisy Maria F , Yeum Kyung‐Jin , Braz José Reinaldo C
Published: June 2021

Genotoxicity of volatile anesthetics such as sevoflurane is still controversial. We evaluated the possible effects of sevoflurane on DNA damage, lipid peroxidation and antioxidant status in patients without comorbidities undergoing minimally invasive surgery with general anesthesia. Fifteen patients classified as physical status (ASA) I, aged 18–44 years old, of both genders, and scheduled for septoplasty or tympanoplasty, received anesthesia maintained with 2%–3% of sevoflurane. Blood samples were collected before anesthesia (T0), 15 min after anesthesia induction (T1), 120 min of anesthesia (T2) and on the first postoperative day (T3). DNA damage in lymphocytes was determined by the comet assay using specific enzymes to detect oxidized purines and pyrimidines. Plasma lipid peroxidation (malondialdehyde ‐ MDA) as well as antioxidant capacity were evaluated by a fluorometry. There were no significant differences in DNA oxidized bases and antioxidant capacity (P>;0.05) among the four time points evaluated; however, MDA levels decreased during T2 (P=0.006) in relation to T3. In conclusion, the current study indicates that sevoflurane anesthesia does not induce oxidative stress in patients without comorbidities undergoing minor surgeries, suggesting the safety of this anesthetic regarding genotoxicity.

Supported by FAPESP, Brazil #2009/51110–5
Identification of SCAL1, a novel long non‐coding RNA, induced by cigarette smoke and associated with lung cancer
Authors: Thai Philip , Statt Sarah , Liang Ellen , Campbell Caitlin , Wu Reen
Published: June 2021

Introduction

Lung cancer remains the largest cause of cancer related deaths. Despite numerous gene profiling studies on smoke induced injury in the airways. A novel type of regulatory RNA termed long non‐coding RNA (lncRNA) have been identified in recent years by RNA sequencing. Thus far, limited studies have looked at lncRNAs and lung cancer.

Objective

Determine if specific lncRNAs are associated with lung cancer and can be used as a biomarker for early diagnosis.

Methods and Results

A non‐metastatic prone lung cancer cell line CL1–0 was compared to its derived invasive subtype CL1–5 by RNA sequencing. A specific lncRNA was identified that was highly expressed in the CL1–5 compared to CL1–0 cells. We have termed this gene SCAL1 and found it to be elevated in numerous other lung cancer cell lines compared to normal bronchial epithelial cells. Subsequent studies revealed this lncRNA is located on chromosome 5 and has 4 putative exons with evidence of evolutionary conservation. In normal bronchial epithelial cells, cigarette smoke extract can induce this lncRNA. Studies with siRNA and chromatin immunoprecipitation (ChIP) revealed that SCAL1's expression is NRF2 dependent. Current studies are underway to determine the functional role of this lncRNA in normal and cancer cells.

Conclusions

SCAL1 is a lncRNA that may represent a novel biomarker of smoke induced lung cancer.

Supported by NIH RO1HL096373–01A1 (RW).
Inhibition of HIV‐1 transcription by a tunable chimeric tRNA(Ser)‐nucloelar localizing trans‐activation response element (TAR) decoy
Authors: Stevens Christian , Scherer Lisa , Rossi John , Haushalter Karl
Published: June 2021

In order for HIV‐1 to achieve high‐level transcription of its integrated proviral DNA, the trans‐activator of transcription (Tat) protein must bind to the TAR region of the nascent viral RNA transcript. A TAR decoy is a short RNA oligomer that inhibits HIV‐1 transcription by binding to the Tat protein, thereby competitively inhibiting the TAR‐tat interaction. Previous work has shown that nucleolar‐localization of a TAR decoy by fusion with the U16 small nucleolar RNA (snoRNA) backbone dramatically increases the TAR decoy inhibition efficiency. In this work, the nucleolar‐localized TAR decoy is expressed as the 3′ trailing sequence of a tRNA(Ser) chimeric transcript. Maturation of the tRNA chimera by tRNA processing enzymes releases the U16‐TAR element from the tRNA. Using a dual‐luciferase reporter assay with firefly luciferase under the control of the HIV‐1 long terminal repeat (LTR) promoter, we show that expression of the tRNA‐TAR decoy chimera inhibits HIV‐1 transcription in human HCT116 cells. We also show that mutations in the tRNA(Ser) acceptor stem allow for inhibition efficiency to be tunable.
ER Stress‐independent Noncanonical UPR Activation under Phenformin Treatment
Authors: Yang Liu , Sha Haibo , Xue Zhen , Qi Ling
Published: June 2021

Activation of unfolded protein response (UPR) is associated with disruption of homeostasis in the endoplasmic reticulum and has been implicated in the pathogenesis of many human diseases including obesity and type‐2 diabetes. However, whether metabolic pathways can directly regulate UPR independently of misfolded protein accumulation and ER stress remains unclear. In a test of various metabolic drugs, we show that activation of UPR sensors can be uncoupled from the ER signals. First, treatment with the antidiabetic drug phenformin activates UPR sensors IRE1α and PERK even in the absence of protein synthesis. Second, phenformin treatment strongly activates a PERK mutant only residing in the cytosol. Mechanistically, kinase activities of both IRE1α and PERK are required for the phenformin effect. Moreover, AMPK activation is required but not sufficient to initiate IRE1α and PERK pathways, suggesting the involvement of additional factor(s) under phenformin treatment. Interestingly, activation of the IRE1α, but not the PERK pathway, may partially mediate the cytotoxic effect of phenformin. Together, these findings demonstrate the existence of a noncanonical UPR where activating signals are derived from the cytosol, adding another layer of complexity to the UPR activation under metabolic stress.