bluuebunny/crossref_metadata_2025 huggingface dataset:
mPGES‐1 deficiency increases mortality and aneurysm rupture in a mouse model of intracranial aneurysms
Authors: Silva Ricardo A Peña , Kung David K , Mitchell Ian J , Heistad Donald D , Hasan David M
Published: June 2021

Studies in humans and mice suggest that inflammation plays an important role in formation and rupture of intracranial aneurysms. Prostaglandin (Pg) E2, a byproduct of microsomal prostaglandin E2 synthase (mPGES)‐1, is associated with inflammation and cerebrovascular dysfunction. We hypothesized that mPGES‐1 deficiency protects against rupture of intracranial aneurysms. Intracranial aneurysms were induced in mPGES‐1 KO and WT mice with DOCA‐salt hypertension and an intracranial injection of elastase. Systolic blood pressure and water intake (1% saline) was similar in WT and mPGES‐1 KO mice. Body weight did not change in any group during the experiment. All WT mice survived 3 weeks after the surgery and did not develop signs of subarachnoid hemorrhage (SAH). 73% (8/11)of WT mice developed aneurysmal dilatations in the cerebral arteries without evidence of SAH. In contrast, half of mPGES‐1 deficient mice died or showed signs of SAH during follow‐up. Postmortem analysis showed SAH in 56% (9/16)of mPGES‐1 deficient mice. Unruptured aneurysms with no evidence of SAH were found in 25% (4/16)of mPGES‐1 deficient mice. In conclusion, we found that genetic deficiency of mPGES‐1 is associated with increased aneurysm rupture (p<0.01)and mortality (p<0.05) in a mouse model of intracranial aneurysms. mPGES‐1 appears to play a protective role against rupture of intracranial aneurysms in mice.
Protection from DNBS‐induced colitis by ozonized olive oil in rats
Authors: Abu‐Gharbieh Eman F. , Bayoumi Fatehia A. , Shehab Naglaa G.
Published: June 2021

The aim of this study was to evaluate the potential protective effect of ozonized olive oil (OZO) in 2,4‐dinitrobenzene sulphuric acid (DNBS) induced colitis in rats and to elucidate the role of some antioxidant enzymes in this effect.

The parameters including peroxide, acid and iodine values of OZO were evaluated. The Colitis was induced by intracolonic instillation of 15mg/rat DNBS in rats. Animals were divided into groups, group A: is the control, B and C received 5ml/kg of OZO and olive oil (OO) respectively. Colitis was induced in groups D, E, F and G. Animals in groups E, F received OZO orally in the doses of 2.5 and 5 ml/kg, respectively and group G received 5ml/kg OO for 7 days, starting the day before colitis induction. Colitis was assessed by macroscopic and microscopic damage scores. The levels superoxide dismutase (SOD), glutathione peroxidase (GSH‐Px) and catalase (CAT) were evaluated. Results showed that the damage scores were significantly reduced in a dose response manner in rats pretreated with OZO but not with OO. CAT, GSH‐Px and SOD activities were significantly increased in the inflamed colon in animals pretreated with OZO with respect to inflamed animals. In conclusion, results showed that OZO pretreatment exerts protective effects in DNBS induced colitis and this effect is mediated by stimulation of some antioxidant enzymes.

This research has been funded by the Medical Research Fund‐Dubai Medical College
Screening of novel small molecule inhibitors of NF‐κB activation in lung cancer
Authors: Umstead MaKendra , Du Yuhong , Yoo Min Heui , Khuri Fadlo , Fu Haian
Published: June 2021

Lung cancer is the leading cause of cancer deaths in the United States. Inflammation of the lung resulting from exposure to cigarette smoke and other contributors may exacerbate the initiation, promotion, and development of lung cancer. Nuclear factor‐κB (NF‐κB) is a key transcription factor involved in both inflammation and cancer. NF‐κB remains inactive when sequestered in the cytoplasm by IκB. Activating signals release NF‐κB, allowing translocation to the nucleus. Nuclear NF‐κB initiates transcription of genes related to proliferation, chronic inflammation, and blockage of apoptosis.

Curcumin, a natural product, has been shown to inhibit NF‐κB activation; however, lack of adequate solubility and oral bioavailability reduce its therapeutic potential. Our goal was to identify novel small molecule inhibitors of NF‐κB activation using an image‐based high content screening (HCS) assay for monitoring NF‐κB nuclear translocation. Initial drug discovery efforts screened a small compound library for efficacy in A549 lung cancer cells. This campaign identified promising candidate compounds for animal studies. Large scale HCS resulted in potent compounds that effectively block nuclear translocation of NF‐κB. Selected compounds are under investigation.

Research support provided by the US National Institutes of Health grants P01 CA116676.
Perivascular adipose tissue modulates neurogenic vasorelaxation in rat mesenteric arteries
Authors: Chang Hsi‐Hsien , Lee Yuan‐Chieh , Liu Chin‐Hung , Chiang Chih‐Lung , Lee Tony J. F.
Published: June 2021

We have demonstrated that palmitic acid methyl ester (PAME) is the major perivascular adipose tissue (PVAT)‐derived relaxing factor. PAME also was shown to inhibit nicotinic acetylcholine receptor (nAChR)‐mediated inward currents on the superior cervical ganglionic neurons. The present study, therefore, was designed to determine if PAME released from the PVAT inhibited nicotine‐induced neurogenic relaxation of isolated endothelium‐denuded small mesenteric arterial (sMA) rings of 8‐week old male Sprague‐Dawley rats. In tissue bath myography study, nicotine (100 μM) induced small, basal relaxation in sMA rings with PVAT. The relaxation was significantly enhanced in arteries without PVAT. Transmural nerve stimulation (TNS) also elicited tetrodotoxin‐sensitive relaxation of sMA rings with or without PVAT. The relaxations in both ring preparations, however, were not significantly different. In sMA preparations with PVAT, TNS‐elicited relaxation or nicotine‐induced small, basal relaxation was not significantly affected by 4‐propargylglycine (10 mM, an inhibitor for H2S synthesis). These results suggest that PVAT, most likely via release of PAME but not H2S, modulates the neurogenic control of the sMA tone. (supported by Tzu Chi Univ & Foundation, NSC and NHRI of Taiwan).
Pharmacological characterization of α2‐adrenoceptor subtypes mediating inhibition of sympathetic vasopressor responses to B‐HT 933 in pithed rats
Authors: Sanchez‐Lopez Araceli , Villalmil‐Hernández Ma. Trinidad , Alcántara‐Vázquez Oscar , Centurión David
Published: June 2021

α2‐adrenoceptors were described as presynaptic receptors inhibiting the release of various transmitters from neurons in the peripheral nervous system. This study analyzed the subtype(s) involved in the inhibition produced by the α2‐adrenoceptor agonist, B‐HT 933, on the vasopressor responses. Male Wistar rats were prepared to stimulate the vasopressor sympathetic outflow (T7–T9) or to receive i.v. bolus of noradrenaline. Sympathetic stimulation or noradrenaline produced, respectively, frequency‐dependent and dose‐dependent vasopressor responses. I.v. continuous infusion of B‐HT 933 failed to modify the vasopressor responses to noradrenaline and inhibited those induced by stimulation of the vasopressor sympathetic outflow (0.03–3 Hz). The sympatho‐inhibition to B‐HT 933 was unaffected by vehicle, but was abolished by rauwolscine and significantly blocked by the antagonists BRL44408 (α2A), imiloxan (α2B) and JP‐1302 (α2C). These doses of antagonists did not modify per se the sympathetically‐induced vasopressor responses. These results suggest that the vasopressor sympatho‐inhibition to B‐HT 933 is primarily mediated by activation of α2A/2B/2C‐adrenoceptors in pithed rats. This project was funded by Conacyt (Grant number 152534).
Effects of glucose concentration on propofol cardioprotection against ischemia‐reperfusion injury in isolated rat hearts
Authors: Tao Mingzhe , Liu Hui‐min , Zhang Ping , Xia Zhengyuan
Published: June 2021

The anesthetic propofol protects against myocardial ischemia‐reperfusion injury (IRI) by reducing reactive oxygen species (ROS)‐induced oxidative stress. However, its cardioprotection in patients is inconsistent. We postulated that low glucose(LG) as seen during tight glycemic control promotes cardiac ROS formation through enhancing fatty acid(FA) oxidation during IRI and unmasks propofol cardioprotection. Rat hearts were isolated and randomly assigned to be perfused with Krebs‐Henseleit solution with glucose at 5.5 mmol/l (LG) in the absence or presence of propofol (5ug/ml) or propofol with trimetazidine (TMZ) unknown to inhibit FA oxidation, or with glucose at 8 mmol/L (group G) in the absence or presence of propofol or propofol plus TMZ. Hearts were subjected to 35 min of global ischemia and 60 min of reperfusion. Myocardial infarct size(IS) was higher in LG than in G group (P<0.05), accompanied with reduced left ventricular (LV) developed pressure and increases in postischemic cardiac contracture. Cardiac 15‐F2t‐isoprostane was higher in LG that was associated with higher cardiac lipid transporter CD36 protein expression than in G group. Propofol reduced IS and improved cardiac function and reduced cardiac CD36 in G but not in LG group. TMZ facilitated propofol cardioprotection in LG. During IRI, LG through enhancing fatty acid oxidation and oxidative stress compromised propofol cardioprotection.
In vitro evaluation of the effects of traditional herbal formulas on human Cytochrome P450 isozymes
Authors: Jin SeongEun , Ha Hyekyung , Shin HyeunKyoo
Published: June 2021

The aim of this study was to assess influence of Sagunja‐tang (SGT; Sizunji‐tang, Shikunshi‐to), Samul‐tang (SMT; Siwu‐tang, Shimotsu‐to), Palmul‐tang (PMT; Bawu‐tang) and Sipjeondaebo‐tang (SJT; Shiquandabu‐tang, Juzentaiho‐to) on the activities of human cytochrome P450 (CYP450), a drug‐metabolizing enzyme. These popular herbal formulas have been used in Asian countries for the prevention and treatment of various diseases. Herbal formulas usually consist of mixtures of crud drugs, and the chance of herb–drug interactions may increase when they are coadministered with conventional drugs. In this study, we established in vitro fluorescence‐based enzyme assays for major human CYP450 isozymes (CYP3A4, CYP2C19, CYP2D6 and CYP2E1) using Vivid® CYP450 Screening Kits. Among these four CYP450 isozymes, CYP2C19 was inhibited by all the tested herbal formulas. In contrast, SGT, SMT and SJT inhibited CYP2E1‐mediated metabolism; and PMT exhibited comparatively weak inhibition of CYP2E1. However, none of the four herbal formulas significantly affected CYP3A4 or CYP2D6. These results suggest that SGT, SMT, PMT and SJT could potentially inhibit the metabolism of coadministered drugs of which primary route of elimination is via CYP2C19. In addition, clinically relevant pharmacokinetic interactions could occur when SGT, SMT or SJT is coadministered with drugs metabolized by CYP2E1. Overall, our findings provide information for the safe and effective clinical use of these four herbal formulas.
Immunogenicity of trimethoprim‐sulfamethoxazole in SIV‐infected rhesus macaques
Authors: Wong Yat Yee , Watson Kal , Trepanier Lauren
Published: June 2021

HIV infected patients have a high risk of hypersensitivity (HS) reactions to trimethoprim/sulfamethoxazole (TMP/SMX). To understand this, simian immunodeficiency virus (SIV)‐infected rhesus macaques were used to explore possible metabolic and immunologic risk factors. SIVmac239‐infected male macaques and non‐infected controls were administrated TMP/SMX (120 mg/kg/day) for 14 days. Prior to dosing, plasma was assayed for antioxidants and cytokines, needle liver biopsies were collected for expression arrays, and PBMC were isolated for in vitro toxicity assays. After treatment, urine was collected for SMX metabolites, plasma was analyzed for anti‐drug antibodies, PBMC were tested for drug specific T cells, and lymph node and plasma were assayed for drug adducts. 7 SIV‐infected and 4 control animals have been treated to date. Baseline plasma ascorbate and red cell glutathione were not significantly different between groups. SMX hydroxylamine was significantly more toxic towards PBMC from SIV‐infected animals (37%) compared to controls (2%; P = 0.04). One SIV‐infected monkey developed an erythematous rash on day 7, and was positive for anti‐SMX antibodies; 3 additional monkeys showed T cells reactive to SMX‐nitroso or TMP. These preliminary data suggest that TMP/SMX is immunogenic in macaques as in humans, and that signs consistent with sulfonamide HS may be possible in this model. Funded by R01 GM100784.
Adenylyl Cyclase Type 5 Inhibition During Reperfusion Ameliorates Heart Failure Development
Authors: Bravo Claudio A , Yoon Seonghun , Kudej Raymond K , Lee Grace Jung Ah , Park Misun , Tian Yimin , Vatner Dorothy E , Yan Lin , Vatner Stephen F
Published: June 2021

There are almost no drugs that can be given to patients with myocardial infarction (MI) after coronary artery (CA) reperfusion (R) to protect against heart failure (HF) following myocardial infarction. A key reason for this is that almost all cardioprotective drugs are effective before CA occlusion (O), but not after CAR, and it is not practical to treat patients prior to CAO. We examined the antiviral drug, AraAde, which has cardioprotective actions of selective adenylyl cyclase isoform type 5 (AC5) inhibition and a structure resembling a potent cardioprotective agent, adenosine. When vehicle was administered to mice after 30 min CAO/CAR, HF developed over the next 4 weeks, characterized by reduced left ventricular ejection fraction (48 ± 2.7%). In mice treated with AraAde after CAR, the ejection fraction was improved (57 ± 2.0%, p<0.05) and the resultant myocardial fibrosis was less (AraAde 2.7 ± 0.2 % vs. vehicle 5.8 ± 0.5%, p<0.05), as was the myocyte apoptosis (AraAde 0.04 ± 0.03% vs. vehicle 0.14 ± 0.03%, p<0.05). Thus, AraAde is a novel drug that inhibits adenylyl cyclase type 5 and protects the heart from development of MI induced HF, when delivered after CAR, a key clinically useful feature, where patients with MI require CAR immediately.
Mechanical Strain in Vascular Smooth Muscle Induces Osteopontin Expression via a Hydrogen Peroxide Dependent Mechanism
Authors: Caesar Christa , Lyle Alicia , Taylor W Robert
Published: June 2021

Recent studies suggest elevated mechanical strain in disease states, such as hypertension, leads to vascular inflammation. However the underlying molecular mechanisms modulating this process are still largely unknown. In this study, we use in‐vivo and in‐vitro approaches to determine if elevated mechanical strain increases osteopontin (OPN), a pro‐inflammatory protein, in a hydrogen peroxide (H2O2) dependent manner. In two mouse models of hypertension, induced via angiotensin‐II and norepinephrine, we found that aortic OPN mRNA expression was increased 7‐fold (p<0.05) and 2.5‐fold (p<0.05) respectively. In‐vitro studies utilizing rat aortic smooth muscle cells that were cyclically strained showed ~3‐fold (p<0.001) increase in OPN mRNA and ~5‐fold (p<0.001) increase in secreted protein expression. H2O2 levels were also increased 4‐fold (p<0.05) in cyclically strained cells. Finally, to determine if increased OPN is H2O2‐dependent, cells were simultaneously stretched with PEG‐Catalase, a H2O2 scavenger, which blunted OPN expression by 65.14% ± 0.22 (p<0.05). These results suggest that elevated mechanical strain, as experienced by the vascular wall under hypertensive conditions, could lead to increases in inflammatory protein expression, such as osteopontin, via a H2O2‐dependent pathway. Research is supported by an AHA Predoctoral Fellowship 2012–14, NIH RO1‐HL090584, HL70531, and HL062820.
In vivo loss of estrogen increases voltage‐gated calcium channel function in mesenteric arterial smooth muscle cells
Authors: Fernando Charmain A , Gray William R. , Walker Azida , Hill Brent J.F.
Published: June 2021

The presence of estrogen in premenopausal women protects against the development of vascular dysfunctions, such as hypertension. Previous studies from our lab demonstrated a slight (p=0.12) increase in voltage‐gated, L‐type Ca2+ channel (CaL) expression in mesenteric arteries from ovariectomized (OVX) mice. Therefore, in this study we hypothesized that the in vivo loss of estrogen will increase Ca2+ influx in mesenteric arterial smooth muscle cells. Mice (C57BL/6) underwent an ovariectomy or sham surgery at 8 weeks of age. At 12 weeks, the mice were sacrificed, mesenteric arteries dissected, and smooth muscle cells isolated. Lack of gonadal estrogen production was verified by a reduction in uterine weights. No significant difference (p=0.496) in weight gain between mice groups was observed. Ratiometric fluorescent imagining was conducted on isolated cells loaded with the Ca2+ fluorescent dye, fura‐2AM. Cells isolated from the mesenteric arteries of OVX mice (n=23) demonstrated an increased (p<0.001) intracellular Ca2+response to the CaL agonist, FPL64176 (1×10−6), compared to the sham mice (n=15). We plan to conduct whole cell Ca2+ currents on these cells in the future. These results suggest that the loss of in vivo estrogen leads to the enhanced influx of Ca2+into arterial cells which may lead to a chronic elevation of vascular tone in postmenopausal women. Support: NIGMM of the NIH, Grant #P20 GM103429–11
Effects of vitamin E supplementation and exercise on endothelial function in rat aortas
Authors: Hoffman Rebecka M , Olesiak Matthew , Harris M. Brennan
Published: June 2021

Acute endurance exercise impairs endothelial dependent dilation whereas chronic endurance exercise improves endothelial dependent dilation which may be related to changes in redox status. The purpose of this study is to determine whether vitamin E supplementation alters endothelium dependent vasorelaxation in response to acute and chronic endurance exercise. 8–9 month‐old, male, Wistar rats were divided into six groups (n=10–12/group): sedentary (S), 1 day (1C), 1 day + vitamin E (1DE), 2 week (2WK), 2 week + vitamin E (2WKE), 6 week (6C), and 6 week + vitamin E (6WKE). Rats ran on a motor‐driven treadmill at 15 m/min, 15% grade for 40 min (1D) increasing up to 1 h by 2 weeks (2WK) and sustained for an additional 4 weeks (6WK). Aortic dose response curves to phenylephrine (PE, 10−7–10−4 M), sodium nitroprusside (SNP, 10−8–10−5 M), and acetylcholine (ACh, 10,−7–3×10−5 M) were constructed. Acute (1 day) endurance exercise significantly impaired Ach‐induced vasorelaxation in aortas which was attenuated by vitamin E supplementation. Chronic exercise (2WK and 6WK) with or without vitamin E supplementation resulted in no significant changes in vascular function. eNOS expression was significantly increased in all exercise groups regardless of supplementation. These data suggest acute exercise impairs endothelium dependent relaxation through oxidative stress which can be attenuated by vitamin E supplementation.
Elevated preload is critical for synchronization of myocardial lengthening (é) and mitral inflow (E) in acute ischemic acute heart failure
Authors: How Ole‐Jakob , Næsheim Torvind , Bakkehaug Jens Petter , Kondratiev Timofey , Remme Espen , Myrmel Truls
Published: June 2021

Background

Tachycardia in ischemic acute heart failure (AHF) is believed to be a compensatory response to sustain cardiac output and perfusion pressure. Little is known about early diastole in this setting.

Methods

In a pig model (n=8, mean±SD) we simultaneously measured myocardial strain (sonometric crystals), mitral‐inflow (conductance‐catheter) and mitral‐pressure difference MITRP (LV‐LA micromanometer). Pacing‐induced tachycardia was induced in the control state and in ischemic AHF (following coronary microembolization).

Results

Tachycardia (160 bpm) shortened the long axis é‐delay (see Figure) from 43±30 to 20±21 ms (p=0.0066), compared to E wave in control, but not in AHF (22±13 to 25±17 ms). Interestingly, by reducing preload to similar levels as control, the é‐delay became evident also in the AHF condition (22±13 vs 48±23 ms p=0.0067). Additionally, tachycardia increased peak MITRP from 4±1 to 9±4 (p=0.007) mmHg in control, but not in AHF (6±2 to 7±2 mmHg). The enhanced relaxation following tachycardia caused a maintained potential energy across the mitral valve in early filling phase (MITRPINTG) in control (0.4±0.2 to 0.4±0.2 mmHg*s), which was reduced following tachycardia in AHF (0.6±0.2 to 0.4±0.2 mmHg*s p=0.0246).

Conclusion

Tachycardia during AHF fails to hasten é and thereby amplifying the pressure driving force across the mitral valve.
HPLC Rotamer Separation and Determination of an Extract Fraction of a Microbial Pigment
Authors: Greenfield Nathan , Wu Zhiqian , Nimmanapalli Ramadevi , Wang Desuo
Published: June 2021

A bioactive red pigment fraction was extracted from a marine bacterium. The preliminary experimental data suggested that the extracted fraction may belong to a member of prodigiosin family. An HPLC rotamer separation method was developed to define the chemical identity of the isolated bacterial material. The chromatogram of the pigment showed a peak absorption at 530 nm and a typical retention time 5.6 min, same as the prodigiosin standard, when analyzed with a C‐18 column and an isocratic mobile phase of acetonitrile:water (80:20, v/v, 1ml/min, pH=7). Upon lowering the pH value of the mobile phase to 3 with HCl, the HPLC chromatogram of the nominally purified pigment showed two distinct absorption peaks. The separation of the parent (α rotamer) and daughter (β rotamer) peaks was pH‐ and temperature‐dependent. At the optimal condition (5°C and pH=3), the size of the β peak is approximately 30% of the α peak. All these parameters of rotamer separation of the unknown microbial pigment are identical to that of prodigiosin. Therefore, we suggest to use this simple and practical rotamer separation method to determine if an unknown red pigment belongs to prodigiosin family.
The effects of estrogen and exercise on cardiac telomere related factors in ovariectomized mice
Authors: Patel Anisha , Witkowski Sarah
Published: June 2021

Loss of estrogen plays a key role in the cardiovascular health of women, and may be linked to cellular aging. While physical activity has been associated with changes in telomere shelterin components and telomerase activity in the heart, the effects of estrogen are unknown.

Objective

To determine whether estrogen and/or exercise alters cardiac telomere‐related gene expression in ovariectomized (OVX) mice.

Methods

Myocardial gene expression was examined in four groups: OVX, sham surgery (SHAM), OVX with exercise (OVX‐EX, 8 weeks of wheel running), and OVX with estrogen supplement (OVX+E2). Telomere length was determined by PCR by telomere Ct to single copy gene Ct ratio (Cawthon 2002, Callicott and Womack 2006). Gene expression was determined via RT‐PCR for mTERT, Acd, Trf1, Trf2, Pot1a, Pot1b, Ku70, Ku80, and normalized to GAPDH. 1‐way ANOVAs with appropriate post‐hoc tests were used to determine differences between groups.

Results

Telomere length (TL) was significantly lower in OVX+E2 compared with SHAM (p=0.008). Expression of mTERT, Acd, and Ku80 were lower in OVX compared with SHAM but were also lower in OVX‐EX and OVX+E2 (all p<0.05). Expression of Pot1b was higher in OVX+E2 compared with OVX‐EX (p=0.009).

Conclusion

OVX, E2 and EX appear to alter cardiac telomere related factors however, neither EX nor E2 attenuated the gene expression changes related to OVX.

Research Funding: UMass Faculty Research Grant
Activation of G‐protein‐coupled estrogen receptor induces coronary artery smooth muscle re‐differentiation and inhibits migration
Authors: Szynkarski Claudia , Yu Xuan , Li Fen , White Richard , Heaps Cristine L , Stallone John N , Han Guichun
Published: June 2021

Estrogen attenuates vascular smooth muscle cell (VSMC) proliferation and migration. Although activation of the G‐protein‐coupled estrogen receptor (GPER) inhibits VSMC proliferation, an effect of GPER on coronary artery smooth muscle cell re‐differentiation and migration is unknown. We investigated a potential role of GPER in mediating human and porcine coronary artery SMC (CASMC) re‐differentiation, and found that G‐1 (selective GPER agonist) induces an enlarged, rectangular/triangular contractile phenotype with increased α‐actin filament density. Further, G‐1 (10−8M – 10−6M) produced a greater increase in SM22α and smooth muscle α‐actin expression compared to controls. Wound‐scratch migration studies demonstrated that G‐1 (24‐hours) inhibited both serum‐ and PDGF‐stimulated migration of porcine CASMC. In addition, G15 (selective GPER antagonist) attenuated the effect of G‐1. These findings suggest that GPER mediates CASMC re‐differentiation and inhibits migration, and could be novel, non‐genomic mechanism whereby estrogen could attenuate the development of coronary atherosclerotic lesions. (Supported by AHA11BGIA7370061)
Mitochondrial Mechanisms That Regulate Blood‐Brain Barrier Endothelial Cell Hyperpermeability Following Oxygen‐Glucose Deprivation and Reoxygenation
Authors: Alluri Himakarnika , Clayton Robert Patrick , Sawant Devendra , Stagg Hayden W , Wilson Rickesha L , Tharakan Binu
Published: June 2021

Ischemia‐reperfusion (IR) injury that occurs following ischemic stroke and traumatic brain injury induces blood‐brain barrier (BBB) breakdown, hyperpermeability and brain edema. Our objective was to determine the mitochondrial mechanisms that regulate BBB integrity and permeability using an oxygen‐glucose deprivation and reoxygenation (OGD‐R) in vitro model of IR injury. Rat brain microvascular endothelial cell (RBMECs) monolayers grown on Transwell inserts were exposed to OGD‐R for 1 or 3 hours alone or in presence of a caspase‐3 inhibitor Z‐DEVD or L‐ascorbic acid 1 hr prior to OGD or a caspase‐3 siRNA 48 hrs prior to OGD. Monolayer permeability was studied based on FITC‐dextran permeability. RBMECs were exposed to OGD‐R for 1 or 3 hours alone or in presence of L‐ascorbic acid. ROS was measured using DCFDA, cytosolic cytochrome c by ELISA and caspae‐3 activity fluorometrically. OGD‐R for 1 or 3 hours increased monolayer permeability, ROS, cytochrome c levels and caspase‐3 activity (p<0.05). Z‐DEVD, caspase‐3 siRNA and L‐ascorbic acid attenuated OGD‐R induced hyperpermeability (P<0.05). L‐ascorbic acid but not Z‐DEVD decreased ROS formation and cytochrome c levels (p<0.05). Immunofluorescence of ZO‐1 demonstrated disorganization of the TJs and Z‐DEVD and L‐ascorbic acid provided protection. These results suggest a major role for mitochondrial ROS in regulating OGD‐R induced BBB TJ integrity and permeability.
Targeting the melanocortin receptor system to reduce leukocyte recruitment following stroke
Authors: Holloway Paul M , Getting Stephen J , Gavins Felicity N E
Published: June 2021

Leukocyte recruitment has been shown to contribute to a destructive inflammatory response following stroke which exacerbates injury. The melanocortin receptor system (MRS) has been shown to reduce leukocyte recruitment in a number of disease models however the relative contribution of the receptors that mediate these effects (MC1, MC3 and MC4) have yet to be determined. This study aims to evaluate the anti‐inflammatory potential of the MRS in stroke.

In a murine model of global stroke, intravital microscopy revealed significant recruitment of leukocytes within 40 minutes of reperfusion. This leukocyte recruitment was found to be enhanced in MC1 mutant (recessive yellow) mice but not in MC3 null. In WT mice Treatment with the pan receptor agonist α‐MSH reduced leukocyte recruitment. However antagonism of MC3 and MC4 failed to abrogate the anti‐inflammatory effects of α‐MSH by 40 minutes of reperfusion, but was able to blunt these effects at 2h. In vitro experiments using human cells in a flow chamber leukocyte recruitment model, confirmed α‐MSH to reduce leukocyte endothelial interactions in human cells and was found to act upon neutrophils but not the endothelium.

These results suggest an important role of MC1 in reducing leukocyte recruitment early in reperfusion following stroke. However as the inflammatory reaction progresses the role of other MCs may become more prominent.

Funded by the British Heart Foundation
Dyslipidemia in adult offspring induced by high fat diet rats at perinatal period.
Authors: Neto Mario Matiotti , Santos Robervan Vidal , Melo Vitor Ulisses , Macedo Fabrício , de Brito Alves José Luiz , Santos Márcio Roberto Viana , Oliveira Larissa Resende , Santana Michael Nadson Santos , Brito Luciana Catunda , Silva João Henrique Costa , Nasciment Elizabeth , Santos Pauliana Ribeiro dos
Published: June 2021

Studies have shown that hormonal, metabolic and nutritional disorders during the early phase of development and/or in the gestation may lead to transitory or permanent structural and functional changes of several organs of the offspring. Our aim was to investigate the impact of high fat diet during the gestation and lactation on biochemical parameters in the offspring of rats. High fat diet was given from day 1 of gestation until weaning of puppies. The biochemical evaluation was performed at 30, 60 and 90 days after birth from High Fat Diet dams (HFDD, n= 6) or Normal Diet dams (NDD, n= 6). Animals from HFDD group presented hyperglycemia starting from day 30 (119 ± 1.6 vs 94.03 ± 2 mg/dl, p<0.05) and LDL (45 ± 7 vs 23 ± 4 mg/dl, p<0.05). In the day 60 OHFD showed difference at TAG ( 61 ± 3 vs 51 ± 1 mg/dl, p<0.05), TC ( 98 ± 5 vs 75 ± 2 mg/dl, p<0.05), VLDL ( 13 ± 0.69 vs 10 ± 0.2 mg/dl, p<0.05) and decrease HDL (42 ± 3 vs 61.42 ± 4 mg/dl, p<0.05). These findings suggest that high fat diet during pregnancy and lactation leads dyslipidemia in adult offspring rats.

Support: CNPq, Fapitec and CAPES
Role of carotid body chemoreceptors in glucoregulation during prolonged exercise in humans
Authors: Peinado Ana Belén , Johnson Blair D , Taylor Jennifer L , Joyner Michael J
Published: June 2021

This study was performed to examine the role of the carotid bodies (CB) in glucoregulation during prolonged exercise in humans. Six healthy males (35 ± 5 yrs) completed two 120 minute bouts of cycling exercise (65% VO2max), during a dopamine infusion (D; 2 μg/kg/min) to acutely inactivate the CB, or a placebo, saline infusion (P). Arterial blood was drawn for glucose and counter‐regulatory hormones at baseline and during exercise (60–80: 60–80 minute mean; EE: end exercise). All variables at baseline were similar between conditions. Glucose concentration decreased throughout exercise and was similar between trials (60–80: 90 ± 7 vs. 98 ± 14; EE: 75 ± 12 vs. 80 ± 10 mg/dl; D vs. P respectively). However, when compared to baseline values, EE glucose had a greater decrease in 4 subjects during D, whereas 2 subjects had a greater attenuation during P. Glucagon was similar at 60–80 (108 ± 42 vs. 84 ± 40 pg/ml; D vs. P respectively), but was greater at EE in D than P (204 ± 104 vs. 136 ± 70 pg/ml). Cortisol (60–80: 13 ± 5 vs. 16 ± 4; EE: 22 ± 3 vs. 20 ± 7 μg/dl; D vs. P respectively) and growth hormone (60–80: 13 ± 3 vs. 12 ± 3; EE: 12 ± 4 vs. 10 ± 4 ng/ml; D vs. P respectively) concentrations were not different between conditions. Our preliminary results indicate that blood glucose during exercise with CB desensitization varies between subjects, and that the CB might contribute to blood glucose regulation during exercise. Funding: NIH R01DK090541
A report on the incidence pattern of some ailments and autoimmune diseases among young adults from Erie, PA
Authors: Mastro Alexadra Diane , Vagula Mary C , Al‐Duhumani Ali , Al‐Duhumani Sajaad , Hartnett Jessica L
Published: June 2021

This report presents the incidence pattern of six conditions, namely, myopia, asthma, hyperopia, depression, acid reflux disease and eczema in young adults who are currently living in Erie, PA. The objective of this study is to track the incidence of these conditions among young adults and compare with state and nation's average values. Many conditions which were once very rare have become more prevalent, particularly some types of autoimmune diseases such asthma, eczema, etc. The research method employed was a survey administered to 582 young adults hailing from 21 states and 3 international territories, whose responses to a 2‐page questionnaire formed the raw data. A chi‐square was performed using the Statistical Package for the Social Sciences (SPSS) to compare number of disease reported (0–6) by gender. 22 females and 5 males reported having two diseases while the expected count should have been 16.1 and 10.9, respectively(X2(5, N= 149) = 12.06, p=.034). Finally, it is noted that 47% population had myopia, 14.6% asthma, 11.3% hyperopia, 8.6% depression, 6.7% acid reflux and 5.1% eczema. The results will be discussed in the light of national and PA state averages.
Heat shock activates transgene CFTR Cl channels
Authors: Bustillo Maria E , Juarez Lindsay , Meiss Lauren , Fischer Horst , Gruenert Dieter C , Illek Beate
Published: June 2021

Loss of transgene expression is a common problem in gene therapy and has limited the effective correction of the cystic fibrosis‐linked CFTR anion channel. Transgene CFTR expression was measured in response to heat shock (BHT, 41–43°C for 60 min) or exposure to small molecule inhibitors of DNA methyltransferases (DNMTi) using CF bronchial epithelial cells (CFBE41o‐) stably expressing wild‐type CFTR under the regulation of the cytomegalovirus (CMV) immediate‐early gene promoter. After 6 hours, BHT induced a significant increase in CFTR mRNA (2.4‐fold), CFTR‐positive cells (5‐fold), and CFTR Cl currents (ICl, 3.6‐fold). Although CFTR mRNA returned to baseline after 24 h, CFTR‐positive cells and ICl remained elevated (3.9 and 2.5‐fold, respectively). Treatment with actinomycin D blunted BHT response suggesting effects on CFTR transcription. 5‐Aza‐dC, a DNMTi, increased CFTR‐positive cells and time‐dependently activated ICl similar to that observed by BHT. A structurally unrelated DNMTi, RG‐108, mimicked effects, whereas native ICl was not affected, suggesting specific regulatory effects on vector‐induced CFTR expression. These studies imply that methylation of DNA CpG sites (likely in the CMV promoter) is a key and reversible factor modulating transgene CFTR expression.
Exercise‐induced up‐regulation of skeletal muscle Nampt protein is independent of α2 AMP‐activated protein kinase
Authors: Brandauer Josef , Vienberg Sara Gry , Andersen Marianne Agerholm , Kristensen Jonas Møller , Wojtaszewski Jørgen FP , Richter Erik A , Treebak Jonas T
Published: June 2021

Deacetylases such as sirtuins convert nicotinamide adenine dinucleotide (NAD) to nicotinamide (NAM). NAM must be reconverted to NAD by nicotinamide phosphoribosyltransferase (Nampt) to ensure maintenance of deacetylase activity. We employed murine models of reduced skeletal muscle activity of AMP‐activated protein kinase (AMPK) to determine whether exercise‐mediated increases in skeletal muscle Nampt are dependent on AMPK activity.

A single bout of acute exercise (90 min, 10 – 17 m/s, 10% slope) increased skeletal muscle Nampt mRNA to similar degrees in both wild type (WT) and AMPKα2 knockout (KO) mice three hours after exercise cessation (WT sedentary vs. exercise, 1.00±0.17 vs. 1.55±0.23 arbitrary units [AU, mean ± SEM], KO sedentary vs. exercise, 0.97±0.22 vs. 1.29±0.19, n=6–7, p<0.05). Nampt protein in quadriceps muscle of AMPKα2 kinase dead (KD) mice was reduced relative to WT mice (p<0.05), and 6.5 weeks of combined voluntary wheel cage (7 d/week) and forced treadmill (5 d/week) exercise training increased quadriceps Nampt protein content of WT and KD animals to a similar degree (WT sedentary vs. trained 1.00±0.07 vs. 1.24±0.08 p<0.05, KD sedentary vs. trained, 0.89±0.05 vs. 1.05±0.07 AU, n=12–15, p<0.05).

Despite reduced Nampt protein concentrations in skeletal muscle lacking a functional AMPKα2 subunit, exercise‐mediated Nampt protein gains do not appear to be dependent on α2 AMPK activity.
Effect of a work‐matched bout of lengthening or shortening contractions on satellite cell proliferation in human muscle
Authors: Hyldahl Robert D , Olson Ty , Magoffin Ryan , Leavitt Michael G , Parcell Allen C
Published: June 2021

Purpose

To determine the extent of satellite cell (SC) activity following a work‐matched bout of lengthening (LC) or shortening (SHC) contractions.

Methods

Participants (aged 22.6 ± 1.5 years) were assigned to either LC (n=6) or SHC (n=6). A control muscle biopsy was taken from the non‐exercised leg prior to exercise. Subjects performed a bout of unilateral LC or SHC of the knee extensors. A biopsy was obtained from the exercised leg 24 h after exercise. Muscle soreness and strength were assessed pre‐, immediately post‐exercise, and every 24 h for 4 d. Immunohistochemistry was used to quantify total and fiber‐type specific SC content from exercised and control legs in LC and SHC. Repeated‐measures ANOVA (p<0.05) was used to analyze data.

Results

Participants performed 40.8 ± 2.9 KJ of work, with no differences between groups (p=0.65). LC caused greater soreness than SHC (p<0.01). LC resulted in prolonged strength loss that recovered 4 days post‐exercise (p<0.01). SHC caused immediate but not prolonged strength loss. SC per muscle fiber increased following LC (0.106 ± 0.031 and 0.126 ± 0.048 pre‐ and post‐exercise, respectively; p=0.028), while SHC caused no change in SC number (0.095 ± 0.025 and 0.101 ± 0.032 pre‐ and post‐exercise, respectively). There was no fiber type‐specific SC response.

Conclusion

We confirm SC activation following LC and show that a single bout of non‐damaging SHC does not stimulate SC activity.
Cardiovascular and behavioral responses to novelty stress after single or dual orexin receptor blockade in the rat
Authors: Carrive Pascal , Bieg Irfan
Published: June 2021

Orexins play a critical role in the regulation of arousal by acting on two receptors, OX1 and OX2. We have previously reported that blockade of OX1 and OX2 with the dual receptor antagonist Almorexant reduces the cardiovascular and behavioral responses to novelty stress. The aim of the study was to compare Almorexant to two new selective OX1 and OX2 antagonists. Rats implanted with telemetric probes were given i.p. injections of either Almorexant, ACT‐335827 (OX1 antagonist, Actelion Pharmaceuticals), or EMPA (OX2 antagonist, Roche) and after 2.5 hours were subjected to novelty stress for 30 min. In vehicle‐injected rats, Novelty increased locomotor activity, blood pressure and heart rate. At 30 mg/kg, Almorexant (n=12) significantly reduced the locomotor and cardiac responses, but neither ACT‐335827 (n=12) nor EMPA (n=8) nor a cocktail of ACT‐335827 and EMPA (n=8) had any significant effect. At 100 mg/kg, Almorexant (n=10) significantly reduced all three responses, ACT‐335827 (n=9), the pressor and cardiac but not locomotor response, EMPA (n=10) the cardiac response only and the cocktail of ACT‐335827 and EMPA (n=11) all three responses at the same magnitude as Almorexant. Thus, systemic blockade of one orexin receptor alone is not sufficient to produce the same effect as blockade of both receptors, at least for novelty stress. The two receptors may act synergistically.

Supported by NHMRC‐Australia
Mitochondrial morphological changes and electron transport chain (ETC) uncoupling induced by Angiotensin II (Ang II) in neuronal cells of the subfornical organ (SFO) and cultured neural cells
Authors: Sarkar Pallabi , Young Colin N , Pierce Joseph P , Zhou Ping , Iadecola Costantino , Davisson Robin L
Published: June 2021

The SFO plays a critical role in the development of hypertension in response to elevated levels of circulating Ang II. Recent evidence suggests that in peripheral tissues and in brain regions involved in cardiovascular regulation, Ang II causes mitochondrial dysfunction that is often accompanied by morphological changes. Here we tested the hypothesis that in the SFO and in Neuro‐2A cells, Ang II causes both morphological and functional changes in the mitochondria. Osmominipumps were inserted in C57BL6 mice for infusion of Ang‐II (600 ng/kg/min) or vehicle for 14 days. Brains were then harvested for electron microscopy (EM). EM revealed that SFO neurons in the Ang II group exhibited reduced area per mitochondrial profile (vehicle 93740 ± 6348 μm2; Ang II 76287 ± 3527 μm2; p < 0.05; n=81–109) and increased number of mitochondria per unit area (Ang II 9.9 ± 1.3; vehicle 6.6 ± 0.8, p < 0.05), indicating reduction in size. For assessment of mitochondrial function, Neuro‐2A cells were incubated with Ang II (300 nM, 24 h) for O2 consumption measurement. Ang II altered mitochondrial respiration (1.63±0.2 nmol/min/mg; vehicle 1.03±0.2, p < 0.05) and reduced the ETC coupling ratio (54 ± 12%, p < 0.05). These findings suggest that Ang II induces alterations in mitochondrial size and bioenergetics that may play a role in the mechanisms by which SFO neurons contributes to Ang II‐dependent hypertension. HL63887, HL96571, HL84207
Medroxy‐progesterone acetate (MPA) treatment increases pentobarbital resistance in neurons within the pre‐Botzinger complex (PBC), consistent with increased epsilon subunit expression in GABAA receptors (GABAARs)
Authors: Turner Sara , Johnson Stephen
Published: June 2021

PBC neurons are critical for inspiratory rhythm generation and naturally increase epsilon subunit expression in GABAARs during pregnancy. Since epsilon subunits confer resistance to positive allosteric modulators (allopregnanolone and pentobarbital) that enhance chloride ion influx, epsilon expression may protect breathing during pregnancy when central allopregnanolone levels increase 3‐fold. We hypothesize that increased epsilon subunit expression increases when central neurosteroid concentrations are increased. Thus, we tested whether MPA treatment (progesterone analogue, 10 mg/kg, SQ, 7 days) increases epsilon subunit expression in the PBC. Multichannel electrodes were used to record spontaneous action potentials of PBC‐region neurons in medullary slices from control (n=7) and MPA‐treated (n=4) P30 rats before bath‐application of 300 μM pentobarbital. In neurons (n=68 cells) from control rats, the mean neuronal firing rate decreased to 44 ± 5% of baseline; 13% of cells were pentobarbital resistant. In neurons (n=31) from MPA‐treated rats, the mean neuronal firing rate was 91 ± 12% of baseline; 52% of cells were pentobarbital resistant. These data suggest that increased central neurosteroid levels are sufficient to increase epsilon expression in PBC‐region neurons, and thereby protect inspiratory motor output from excessive inhibition. Supported by NIH T32 HL07654.
Impact of Cumulative Final Exams in Undergraduate Anatomy and Physiology Courses
Authors: Gray Joseph Kerby , Shaw Donald
Published: June 2021

The vast majority of science courses at undergraduate academic institutions follow routine and well established class formats which have been engraved in the structure of universities for decades. A student's grade in a typical undergraduate anatomy and physiology class is primarily composed of 3–5 tests, a lab score, and a cumulative final exam that can be anywhere from approximately 20% to as high as 35% of the overall average depending on the course. The aim of this study was to examine the impact that cumulative final exams have on students’ grades, and thereby determine if the exams were beneficial or detrimental to the students’ performance in the course. Since students majoring in the sciences comprise the majority of the future medical and research workforce it is imperative to examine the impact, if any, these heavily weighted final exams have on their undergraduate career. A large sample size (n=364) was used from 10 different semesters of anatomy and physiology classes at the University of Tennessee at Martin. In each class the test format was very similar and contained a mixture of multiple‐choice, short answer, and practical identification questions. Over the 10 semesters of data examined by the study, the final exam comprised an average of 28% of the total grade per semester. Using statistical methods including standard deviation and a t‐test, the magnitude and direction of grade fluctuations after the final exam was determined relative to the course grades before the final exam. The results showed that the grades were significantly lower after the final exam when compared with the grades before the final exam (alpha at 0.05 level and t‐value was 0.00121). Based on these results we concluded that, on average, cumulative final exams in anatomy and physiology courses are detrimental to students’ overall grade.
MUC1‐C ACTIVATES C/EBPβ‐MEDIATED INDUCTION OF ALDEHYDE DEHYDROGENASE EXPRESSION IN BREAST CANCER CELLS
Authors: Ahmad Rehan , Alam Maroof , Rajabi Hasan , Kufe Donald W
Published: June 2021

Aldehyde dehydrogenase 1A1 (ALDH1A1) activity is used as a marker of breast cancer stem cells; however, little is known about the regulation of ALDH1A1 expression. Mucin 1 (MUC1) is a heterodimeric protein that is aberrantly overexpressed in >;90% of human breast cancers. The present studies have been performed on breast cancer cells that are stably silenced for MUC1 expression or overexpress the oncogenic MUC1‐C subunit. We demonstrate that MUC1‐C is sufficient for induction of MEK→ERK signaling and thereby ERK‐mediated activation of the CCAAT/enhancer‐binding protein β (C/EBPβ) transcription factor. In turn, MUC1‐C and C/EBPβ form a complex on the ALDH1A1 gene promoter and activate ALDH1A1 transcription. The results further show that MUC1‐C‐induced upregulation of ALDH1A1 expression is associated with marked increases in ALDH activity as detected by the aldefluor assay. In concert with these results, we demonstrate that MUC1‐positive breast cancer cells are also aldefluor‐positive. These findings indicate that (i) MUC1‐C activates a novel ERK→C/EBPβ→ALDH1A1 pathway, and (ii) MUC1‐C contributes to the induction of stem cell‐associated ALDH activity in breast cancer cell populations.
The Efficacy of the Mediterranean Diet on Obesity Outcomes: A Meta‐Analysis
Authors: Garcia Marissa , Shook Julia , Kerstetter Jane , Kenny Anne , Bihuniak Jessica , Huedo‐Medina Tania
Published: June 2021

Objective

The impact of a Mediterranean Diet (MD) on obesity is inconclusive. Therefore, the current study was designed to assess the efficacy of this intervention in reducing obesity outcomes and identify moderators of intervention efficacy.

Methods

We reviewed 16 out of 83 articles published between 1994 and 2014 that met the inclusion criteria, including pre‐ and post‐measurements of weight, waist circumference (WC), or Body Mass Index (BMI), use of the Mediterranean Diet as a dietary intervention and sufficient statistical information to calculate effect sizes. Effect size (d+) was calculated as the standardized mean difference of pre‐ and post‐dietary intervention adjusting for small sample size. All data were analyzed using random‐effects assumptions.

Results

Analysis of 16 reports shows that out of the 2,852 participants, 67.6% were female with an average mean age of 44.5 years (SD=9.8). A majority (75%) of the studies analyzed were conducted in Europe. There were significant decreases in weight, BMI, and WC from baseline to follow‐up with the use of the Mediterranean Diet as the intervention (d+= ‐0.53, 95% CI from ‐0.79 to ‐0.25; d+= ‐0.49, 95% CI from ‐0.75 to ‐0.24; d+= ‐0.43, 95% CI from ‐0.75 to ‐0.09, respectively). Length of the intervention explained more than 50% of the variability of the effect sizes; the longer the intervention, the greater the reduction in obesity outcomes by 0.01 standard deviation of the effect per week.

Conclusions

In addition to the well‐known antiatherogenic effects of the MD, this diet appears to be effective in reducing obesity outcomes with increased effects when followed for longer periods of time.