bluuebunny/crossref_metadata_2025 huggingface dataset:
Pharmacological treatment with a melanocortin analogue protects against pressure‐overload‐induced cardiac hypertrophy
Authors: Rinne Petteri , Ruohonen Suvi T , Ruohonen Saku , Savontaus Eriika
Published: June 2021

Melanocortins regulate important physiological functions such as energy balance and blood pressure, but their long‐term effects on cardiac remodeling remain unexplored. Therefore, using gain‐of‐function models of melanocortin activity, we investigated whether melanocortins affect physiological or pathological cardiac growth. First, we studied the effects of transgenic melanocortin overexpression (MSH‐OE) on physiological age‐related cardiac growth. 6‐month‐old MSH‐OE mice had lower heart weight with maintained cardiac function compared to age‐matched wild‐type mice. Second, we examined the effects of a stable melanocortin analogue (MT‐II) on pressure‐overload‐induced cardiac hypertrophy. We subjected 8‐week‐old C57Bl/6N mice to transverse aortic constriction (TAC) and treated them with either saline or MT‐II (0.3 mg/kg/day for 6 weeks, i.p.). Saline‐treated TAC mice displayed significant increases in ventricular weight and LV posterior wall thickness, and impaired systolic function compared to sham‐operated control mice. This pathological cardiac remodeling was attenuated in MT‐II‐treated TAC mice. Importantly, MT‐II‐treatment did not compromise cardiac function, but tended to rather improve LV contractility in TAC mice. In conclusion, these results establish melanocortin signaling as an antihypertrophic regulator in physiological and pathological cardiac remodeling.
HMW‐way and LMW‐way: different routes of cerebral extravasation by Evans blue and sodium fluorescein
Authors: Yen Lola Fenghuei , Lai Ted Weita
Published: June 2021

Evans blue dye (EBD; 961 Da) and Sodium fluorescein dye (NaF; 376 Da) are commonly used inert tracers in blood‐brain barrier (BBB) research. They are both highly charged low molecular weight (LMW) tracers with similar lipophobic profiles. Nevertheless, EBD strongly binds to serum albumin (69,000 Da) to become a high molecular weight (HMW) protein tracer when injected into the circulation, whereas NaF remains mostly unbound in the circulation. In this study, rats were injected with equal doses of either EBD or NaF to monitor their blood pharmacokinetics and tissue distribution. EBD was largely confined to the circulation with little accumulation in peripheral organ and even less accumulation in central tissue, whereas NaF distributed almost evenly between the blood and peripheral organ but was also largely excluded from central tissue. Importantly, EBD crossed the BBB most effectively at the prefrontal cortex and the cerebellum, and most poorly at the striatum. In marked contrast, NaF was evenly‐distributed throughout the brain. Our study suggest that different regions of the brain are equally permeable to LMW inert dyes like NaF, but are markedly different in permeability to HMW proteins such as EBD‐labelled serum albumin. (Supported by the National Science Council of Taiwan)
The Estrogen‐Mediated Control Of Blood Pressure And Cardiovascular Autonomic Control Are Differentially Modulated By Endothelial And Neuronal Nitric Oxide Synthases
Authors: El‐Mas Mahmoud M , Abdel‐Rahman Abdel A
Published: June 2021

Estrogen (E2) replacement lowers blood pressure (BP) and improves the cardiovascular autonomic control in ovariectomized (OVX) rats. We investigated whether constitutive and/or inducible nitric oxide synthase (NOS) modulate these E2 effects. We evaluated changes in BP, myocardial contractility (dP/dtmax), and power spectral indices of hemodynamic variability following inhibition of eNOS (L‐NIO), nNOS (NPLA), or iNOS (1400W) in telemetered OVX rats treated for 16 weeks with (OVXE2) or without (control, OVXC) E2. OVXE2 rats exhibited (i) reduced BP, and increased dP/dtmax, (ii) enhanced cardiac parasympathetic influence as reflected by decreases in low‐frequency/high‐frequency ratio of interbeat intervals (IBILF/HF), and (iii) reduced LF oscillations of systolic BP, suggesting a reduced vasomotor sympathetic tone. L‐NIO elicited a shorter‐lived pressor response in OVXE2, than in OVXC, rats along with reductions in dP/dtmax and increases in the spectral index of spontaneous baroreflex sensitivity (index α). NPLA reduced BP and increased IBILF/HF ratio in OVXE2 but not in OVXC rats. No hemodynamic changes were caused by 1400W. Overall, eNOS and nNOS exert contrasting tonic modulatory BP effects, which comprise induction of hypotension and hypertension, respectively, in OVXE2 rats. Baroreflex facilitation and dP/dtmax reductions might explain the shorter pressor action of L‐NIO in OVXE2 rats.
Discriminative stimulus effects of emerging arylcyclohexylamine drugs of abuse in rats
Authors: Bauer‐Erickson Jonathan , Norwood Andrew P , Wessinger William D , Fantegrossi William E
Published: June 2021

In recent years, extensive internet availability of a range of “research chemicals” has lead to the emergence of new compounds as drugs of abuse, including arylcyclohexylamine analogues of the non‐competitive N‐methyl‐d‐aspartate (NMDA) receptor antagonist phencyclidine (PCP). In this study, we established PCP as a discriminative stimulus in rats in order to assess the interoceptive effects of emerging arylcyclohexylamine drugs of abuse. Six adult male Sprague‐Dawley rats were gradually shaped to a terminal fixed ratio 20 (FR20) reinforced by food pellets. A pre‐session intraperitoneal injection of 3.0 mg/kg PCP, or saline vehicle, served as a cue to inform the subjects which of the two response levers would be reinforced. Once discrimination was established, substitutions were performed with various doses of PCP, eticyclidine (PCE), tenocyclidine (TCP) or the negative control compound morphine using a cumulative dosing procedure. Using these methods, PCP, PCE and TCP dose‐dependently and fully substituted for the PCP training dose, while morphine occasioned responding primarily on the saline‐appropriate lever up to doses that suppressed response rates. All effective substitution drugs were more potent than PCP, with ED50 values of 1.21±0.21 mg/kg for PCP, 0.23±0.08 mg/kg for PCE and 0.55±0.22 mg/kg for TCP. These results suggest that novel arylcyclohexylamine drugs of abuse are likely to be more potent than PCP, and that human users of these emerging drugs might be more likely to overdose if they base their doses on PCP. Future directions of this experiment include the testing of novel emerging PCP analogues, such as methoxetamine and 3‐methoxyeticyclidine. This work supported by RR020146, RR029884, and by an ASPET SURF award to JBE.
The discriminative stimulus effects of nitrous oxide in B6SJLF1/J mice
Authors: Richardson Kellianne J , Shelton Keith L
Published: June 2021

The abuse‐related CNS effects of nitrous oxide (N2O) are poorly understood. In vitro data suggests that N2O alters the function of NMDA and GABAA receptors, amongst others. Our goal was to assess the neurotransmitter systems responsible for producing the intoxicating effects of N2O using drug discrimination. Twenty‐four mice were trained to discriminate 10 min of exposure to 60% N2O/40% O2 versus 100% O2 in daily 5 min operant sessions. Mice acquired the discrimination in an average of 38 days. N2O produced concentration‐dependent substitution for the training concentration. Full substitution required 7 min of 60% N2O exposure but the offset of stimulus effects N2O following the cessation of exposure was more rapid. In substitution studies the NMDA channel blocker MK‐801 produced up to 49% N2O lever‐selection at 0.56 mg/kg. While MK‐801 failed to produce more than partial substitution, an intermediate dose of 0.17 mg/kg MK‐801 significantly shifted the N2O concentration‐effect curve to the left. The competitive NMDA antagonist CGS 19755 and the positive GABAA modulator midazolam failed to substitute for N2O. Volatile anesthetic vapors methoxyflurane and isoflurane partially substituted for N2O. These data suggest the subjective stimulus properties of N2O may be partially mediated by NMDA antagonism but other receptor systems not yet examined are probably also involved. Supported by NIDA grant RO1‐DA020553.
A humanized anti‐cocaine monoclonal antibody antagonizes cocaethylene entry into the brain in mice
Authors: Dasenbrock Hanna , Tabet Michael R. , Bartley Erin L. , Ball William J. , Norman Andrew B.
Published: June 2021

A humanized anti‐cocaine monoclonal antibody (mAb), h2E2, has been reported to sequester cocaine in the plasma and decrease cocaine concentrations in the brain in mice and to antagonize cocaine‐induced reinstatement of self‐administration behavior in rats. This predicts that h2E2 will decrease the probability of relapse in cocaine abusers. Many cocaine users also abuse alcohol and when cocaine and ethanol are simultaneously ingested, the active metabolite cocaethylene is formed. This potentially compromises the efficacy of h2E2. However, the mAb h2E2 has high affinity for cocaethyene as well as cocaine. In the present study, the ability of h2E2 to prevent cocaethylene entry into the brain was tested. Mice were infused with h2E2 (1.6 μmol/kg i.v.) or vehicle and after one hour were injected with cocaethylene fumurate at a dose equimolar with the mAb. After 5 min, plasma and brain were collected and cocaethylene concentrations were measured by gas chromatography/mass spectrometry with reference to internal and external standards. The h2E2 produced a >; 90% increase in plasma cocaethylene concentrations and a concomitant >; 90% decrease in brain concentrations. The ability of h2E2 to protect the brain from both cocaine and cocaethylene predicts that the clinical efficacy of h2E2 will be retained in cocaine abusers who also co‐abuse alcohol. Supported by NIH grant DPIDA031386 and 2012 ASPET SURF Program.
Azole‐based heme oxygenase inhibitors and their effects on AC2M2 mouse breast cancer growth and metastasis in vivo
Authors: Hum Maaike , Dercho Ryan A , Vlahakis Jason Z , Szarek Walter A , Elliott Bruce E , Nakatsu Kanji
Published: June 2021

Heme oxygenase (HO) catalyzes the breakdown of heme to biliverdin, free iron, and carbon monoxide. The two major isoforms, HO‐1 (inducible) and HO‐2 (constitutive), are involved in a variety of physiological functions, including apoptosis, inflammation and angiogenesis ‐ important in the growth of some types of cancer. Previous work using metalloporphyrin‐based compounds identified HO inhibition as a potential therapy for some cancers. These compounds are limited by their lack of selectivity for HO and inhibit other heme‐dependent enzymes. Novel azole‐based HO inhibitors have demonstrated increased in vitro selectivity for HO and were tested for their effects on breast cancer growth & progression. In vitro experiments included observing the effects on AC2M2 cell viability and endothelial tube growth in an aortic ring model. In vivo experiments involved the implantation of AC2M2 cells into the mammary fat pad of female nude mice, which then received metronomic treatment with an azole‐based compound or vehicle. Primary tumours were removed on day 21 and metastases grew for another 14 days. Based on previous results, we hypothesized that the azole‐based HO inhibitors would decrease primary tumour volume and decrease the incidences of lung metastases, when compared to control. The findings will help determine whether HO is an appropriate target in the treatment of breast cancer. (Funded by the Ontario Institute of Cancer Research 08NOV‐142; MH is the recipient of a Fellowship from the Canadian Breast Cancer Foundation ‐ Ontario Region)
Therapeutic use of eNOS/Caveolin‐1 antagonistic peptides for endothelial dysfunction and atherogenesis
Authors: Sharma Arpeeta , Leung Cleo , Stefanovic Nada , de Haan Judy , Bernatchez Pascal
Published: June 2021

Rationale

Endothelial dysfunction, which is characterized by a reduction in nitric oxide (NO) bioavailability, is an early pro‐atherogenic step. Endothelial nitric oxide synthase (eNOS), the enzyme responsible for the constitutive production of NO, is negatively regulated by its association to Caveolin‐1 (Cav‐1), the major coat protein of caveolae. Whether antagonizing the eNOS/Cav‐1 interaction is an anti‐atherosclerotic drug target is unknown.

Objective

We have recently shown that a mutant Cav‐1 derived peptide (CavNoxin) can increase NO release by antagonizing eNOS binding to Cav‐1 (Bernatchez, Sharma et al., JCI 2011). Since upregulating NO production is therapeutically relevant in atherosclerosis we hypothesized that CavNoxin can attenuate atherosclerotic progression in vivo.

Methods & Results

ApoE knockout mice were placed on a high fat diet for 12 weeks and were injected with either CavNoxin (2.5mg/kg) or vehicle peptide every 3 days. At the end of the 12 weeks, atherosclerotic lesions were analysed. CavNoxin treatment attenuated atherosclerotic lesions in the aorta and aortic sinuses by 42% and 21% respectively, as compared to vehicle controls. In addition, Cavnoxin reduced VCAM‐1 (adhesion molecule) expression and oxidative stress (measured by DHE and nitrotyrosine staining) in vivo.

Conclusion

These data are the first to show an effect of the eNOS/Cav‐1 antagonism in atherosclerosis.
Sex‐specific endothelial cell response to insulin
Authors: Bingaman Susan , Huxley Virginia H.
Published: June 2021

We have observed that following acute exposure to insulin, permeability of mesenteric microvessels to albumin (Ps) differs by sex (S Bingaman et al., FASEB J20 406.7 2006; R Sasaki et al., FASEB J20 205.3 2006).

Occupancy of the endothelial cell (EC) insulin receptor leads to the activation of 2 pathways that generate the vasodilator nitric oxide on the one hand and the vasoconstrictor endothelin‐1 on the other. Given our working hypothesis that agents that are vasodilators elevate Ps, and agents that are vasoconstrictors reduce Ps, we posited that the sex‐specific responses to insulin result from sex differences in the contributions of the 2 pathways.

To evaluate the cell signaling EC isolated from the mesenteries of adult male and female Sprague Dawley rats were grown in culture for up to 7 passages. Cell‐based ELISA was used to assess total and phosphorylated endothelial nitric oxide synthase (eNOS) and MAPK, and insulin receptor‐β (IRβ) expression after 30 minutes exposure to 10−7M Insulin as compared to its absence. Results were normalized against β‐tubulin expression for each group.

IRβ expression was reduced only in EC from males, while both sexes showed differences in eNOS and MAPK expression and activity. These data demonstrate the capacity for vascular cells to retain and display sex‐differences in cell signaling in the absence of sex hormones.

Support: HL093068, HCO6RR017353 & the MU Pulmonary/MPP Partnership
Role of the Angotensin II Type 2 Receptor in thyroid hormone‐induced cardiac hypertrophy in a model of Ischemia/Reperfusion
Authors: SILVA IVSON BEZERRA , SANTOS ROBSON SOUZA , BARRETO‐CHAVES MARIA LUÍZA MORAIS
Published: June 2021

We hypothesize that the cardioprotective effect of TH in ischemia/reperfusion (I/R) model may occur with the participation of AT2R. Mice were subdivided in four different groups: 1) Wild‐Type (treated with saline); 2) Hyperthyroid (treated with T3 0.7 μg/Kg BW/day, i.p., 14 days); 3) AT2R knockout (treated with saline) and 4) Knockout + T3 (treated with T3). Hearts were mounted on a Langendorff apparatus under a constant retrograde flow (2–2,5 ml/min) with oxygenated (95% O2, 5% CO2) Krebs–Henseleit buffer, 37ºC. Cardiac hypertrophy was determined based on heart weight (mg)/tibia's length (mm) ratio. Total T4 levels were determined using a commercial radioimmunoassay kit and cardiac protein expression was analyzed by Western Blotting. Data (mean±SEM) were analyzed by Student's t test, considering p<0,05. T3 treatment was able to induced cardiac hypertrophy which was not changed by AT2R absence. Vasodilator effect of T3 treatment was observed in wild‐type mice while it was abolished in knockout mice. The p‐Akt (Thr 308) levels were significantly increased in T3 group compared to control group in wild‐type mice, but no difference was observed between knockout T3‐treated and AT2R knockout mice. These data point to a possible involvement of AT2R and Akt signaling pathway on cardioprotective effect induced by T3.
Alterations in the nitric oxide / soluble guanylyl cyclase pathway enhance the risk of myocardial infarction
Authors: de Wit Cor , Kaiser Frank , Aherrahrou Zouhair , Koesling Doris , Schunkert Heribert , Erdmann Jeanette
Published: June 2021

Myocardial infarction (MI) results from sudden atherothrombotic occlusion of a coronary artery, exhibits a genetic predisposition and clusters in families. We performed whole exome sequencing and analysed identified targets. In a MI family, heterozygous mutations in two functionally related genes, GUCY1A3, encoding the α1‐subunit of the soluble guanylyl cyclase (α1‐sGC), and CCT7, encoding a chaperonin containing TCP‐1 complex (CCT) protein, segregate with the disease. All family members with the GUCY1A3 (p.Leu163Phefs*24) and the CCT7 mutation (p.Ser525Leu) were affected. Transfection of sGC in HEK cells yielded its expression and NO‐induced cGMP formation, but transfection of the GUCY1A3 mutation was ineffective. Downregulation of CCT7 in VSM decreased sGC expression verifying the importance of CCT7 herein. In platelets of affected probands α1‐sGC and NO‐induced cGMP formation was strongly reduced. Light‐dye induced thrombus formation in arterioles revealed the functional relevance of α1‐sGC. Time to occlusion was shorter in α1‐sGC deficient mice. Inhibition of endogenous NO accelerated thrombus formation only in wildtype and abrogated differences between genotypes indicating an absent inhibitory effect of NO in α1‐sGC−/− mice. In conclusion, dysfunctional NO/sGC signalling may lead to premature MI and α1‐sGC is decisive in continuous inhibition of thrombus formation thereby preventing MI.
Renin antibody staining of reproductive tissues of the rat estrus cycle
Authors: Hurley Mary , DenHaese Jason , Heller Scott , Tyrpak Stephen , Bansal Roli , Manu Pauline , Mosher Nicole , Alden Ashley , Jones Craig Pace , Olivieri Marion Pace
Published: June 2021

Renin is an important kidney vasculature‐produced hormone that is released with a drop in the vascular flow rate through the glomerulus. It activates angiotensinogen, which is altered to angiotensin I, and altered again in lung tissue to angiotensin II, causing a release of aldosterone from the adrenal cortex and an increase in blood pressure, thereby increasing the vascular flow rate through the glomerulus. Renin is also a hox gene product in the mouse, in the abdominal region, found in fetal paired vessels of the abdominal aorta, supplying adrenal glands, kidneys, and gonads. After birth renin is still present in mouse ovarian/uterine artery, but not in the testicular artery. It is also present in giant trophoblast cells of the mouse placenta. Our lab has shown that renin is produced in rat female reproductive tissues, in the ovarian/uterine arteries and giant trophoblast cells, using anti‐mouse renin antibodies. This study examines the sites of renin immunohistochemical staining in rat female reproductive tissues during each stage of the estrus cycle. Anti‐mouse renin antibody generously donated by Dr. Kenneth Gross of RPCI. Research supported by DYC faculty research committee funding.
Relapse of clinical symptoms in the acute experimental autoimmune encephalomyelitis (EAE) is adrenalectomy (ADX) time dependent in the Lewis rat
Authors: Quintanar‐Stephano Andrés , Contreras‐Romo Martha Citlalli , Ibarra‐Pedroza Janeth Alejandra , Zambrano Cynthia , Organista‐Esparza Alejandro , Rodríguez‐Peralta Adriana , González‐Ruíz Claudia Rebeca , Kovacs Kalman , Berczi Istvan
Published: June 2021

Susceptible Lewis rats to acute experimental autoimmune encephalomyelitis (EAE) develop a single episode of paralysis, spontaneous recovery and remain refractory to EAE re‐immunizations. In non‐susceptible rats, EAE induces a strong corticosterone (CO) response protecting against the disease, whereas in the susceptible Lewis rats an inappropriate CO response induces an altered immune response. Here we study the critical time in which CO induce the refractivity to relapses in the EAE by using Lewis EAE‐adrenalectomized (ADX) animals operated at different times of EAE‐immunization. Animals were immunized with guinea pig brain homogenate in CFA (200 μL subcutaneously).

Results

All animals developed an acute episode of EAE symptoms which started at 10–11 days post immunization (DPI), however differences in the clinical course were apparent in the several groups. The Control group developed a single full‐blown disease without relapse. ADX 15 days before immunization and ADX 3 DPI groups developed a lethal form of EAE. ADX 20 DPI group developed a single full‐blown of EAE without relapse. ADX 27 DPI group developed the acute full‐blown symptoms with a full‐blown relapse. ADX 30 DPI group developed a mild but prolonged relapse. The ADX 36 DPI group developed a single full‐blown disease without relapse. Results indicate that there is a critical period (between 20–27 DPI), in which CO suppress the relapses of the EAE.

Supported by UAA‐PIBB11–5 and CONACYT‐62317. México.
Neuroprotective effects of EGCG on H2O2‐ and MPTP‐stressed PC12 cells
Authors: Snitsarev Vladislav , Andrej Anastasia , Rotella David P
Published: June 2021

Parkinson's disease results from degeneration of dopaminergic neurons. EGCG (epigallocatechin gallate), the most abundant catechin in tea and a powerful antioxidant, has been shown to play a neuroprotective role in the presence of degenerative stress inducers. We hypothesized that EGCG would protect a dopaminergic PC12 cell line from H2O2 and MPTP (1‐methyl‐4‐ phenyl‐1,2,3,6‐tetrahydropyridine)‐induced stress. PC12 cells were plated at 104 cells/cm2 in 60 (35 mm) wells. 15 wells were treated with 10 nM EGCG, 15 with 100 nM EGCG, and 15 with 1000 nM EGCG. 5 wells of each EGCG concentration were used as controls with no additional treatments. 5 wells of each EGCG concentration were treated with 100 μM H2O2, 5 wells of each EGCG concentration were treated with 10 μM MPTP, and 5 PC12‐ containing wells were used as the control with no treatment of EGCG. 5 wells were treated with 10μM MPTP only and 5 wells were treated with 100 μM H2O2 only, for a total of 60 wells. The PC12 cells with respective treatments were incubated for 24 hours, and 4 random images of each well were taken, for a total of (60×4) 240 images.

The above figures display PC12 cells treated with maximum concentrations of H2O2 (100 μM) and EGCG (1000 nM) for 24 hours. The results indicate that EGCG plays a neuroprotective role in the presence of oxidative stress stimuli. Similar results were obtained after treating the PC12 cells with MPTP.
Increased cortical CCL3 expression is associated with microglia activation and can be ablated by reducing circulating TGFβ1 during hepatic encephalopathy
Authors: McMillin Matthew , DeMorrow Sharon
Published: June 2021

Hepatic encephalopathy (HE) is a neuroinflammatory complication associated with liver failure. Other neuroinflammatory disorders show involvement of chemokine ligand 3 (CCL3) and its receptor chemokine receptor 1 (CCR1). Transforming growth factor beta 1 (TGFβ1) modulates these proteins and is elevated in the serum during HE. Our aims were to examine CCL3 and CCR1 expression in the cortex and their interactions with TGFβ1 signaling during HE. Male C57Bl/6 mice were injected with azoxymethane (AOM) to induce HE. Neutralizing antibodies against TGFβ or clodronate liposomes were injected prior to AOM. Cognitive impairment was monitored and at coma brains and livers were dissected. CCR1, CCL3 and IBA1 expression was assessed by immunofluorescence and immunoblotting. Microglia activation occurred following AOM treatment and microglia depletion with clodronate liposomes delayed neurological decline in AOM mice. Cortical CCL3 protein, but not CCR1, was significantly elevated in AOM mice. Treatment with neutralizing antibodies against TGFβ delayed neurological decline and decreased CCL3 protein with no effects on CCR1. Our data suggest that microglia activation following AOM could be due to upregulation of CCL3 and that neutralizing antibodies against TGFβ are neuroprotective possibly through the suppression of CCL3 protein in AOM mice.

Research support is provided from NIDDK via 7R01DK082435–03.
Inflammation, oxidative stress, and neuroprotective factors in the pathophysiology of PTSD in an animal model
Authors: Wilson Brad , McLaughlin Leslie , Nair Anand R , Dange Rahul , Francis Joseph
Published: June 2021

Post‐Traumatic Stress Disorder (PTSD) is an anxiety disorder that can develop in response to a traumatic event. To date, no diagnostic biomarkers have been identified for PTSD. Recent research points toward physiological derangements that may be responsible. Studies indicate PTSD may be exacerbated by increased pro‐inflammatory cytokines (PICs) and reactive oxygen species (ROS). In this study, we hypothesized certain PICs and total ROS would be elevated in PTSD animals vs. controls, while brain‐derived neurotrophic factor (BDNF) and neuropeptide‐Y (NPY) would be downregulated. Male Sprague‐Dawley rats were used in this study. We induced PTSD via a predator exposure model, whereby rats were placed in a cage with a cat for 1 hour on days 1 and 11 of the 30‐day experiment. Rats also received psychosocial stress via daily cage cohort changes. Total ROS were elevated in the hippocampus, pre‐frontal cortex, and whole blood in PTSD animals. Messenger RNA levels for IL‐1β and NALP3 were elevated in PTSD animals in the same regions, while BDNF and NPY were lower. These data suggest PICs and ROS are upregulated in the brain and systemic circulation, while BDNF and NPY are downregulated, in an animal PTSD model. This provides evidence that traumatic exposure, independent of physical injury, causes physiological impairments that may influence behavior. All statistics were significant at p<0.05. Research support provided by LSU.
Mas mediated cerebroprotective action of the angiotensin type 2 receptor agonist Compound 21 in ischemic stroke.
Authors: Patel Neal Anil , Joseph Jason , Pioquinto David , Ludin Jacob , Greenstein David , Sumners Colin , Steckelings Ulrike Muscha
Published: June 2021

Recent studies indicate that angiotensin‐(1–7) [Ang‐(1–7)] or the angiotensin type 2 receptor (AT2R) agonist Compound 21 (C21) exert significant cerebroprotective actions against ischemic stroke. Based on recent evidence of dimerization between AT2R and the Ang‐(1–7) receptor Mas, we tested whether the Mas antagonist A‐779 can alter the cerebroprotective actions of C21 against ischemic stroke produced by endothelin‐1 (ET‐1) induced middle cerebral artery occlusion (MCAO). Adult male Sprague Dawley (SD) rats were pre‐treated with A‐779 (0.0075ug/h) or artificial cerebrospinal fluid (aCSF) via intracerebroventricular (ICV) infusion for 7 days prior to ET‐1 induced MCAO. IP administration of C21 (0.03 mg/kg) at 4 and 12 hours post‐MCAO significantly reduced the cerebral infarct size of ipsilateral gray matter, and attenuated the associated neurological deficits when compared with rats that had received IP 0.9% saline at the same time points. ICV infusion of A‐779 abolished the treatment effect of C21 on infarct size and neurological deficits, measured 72 h after MCAO induction (n=13–16), but alone had no significant effects on infarct size or behavioral scores. These data suggest that the cerebroprotective action of C21 either involves activation of Mas or that due to AT2R‐Mas‐heterodimerzation, blockade of the receptor Mas also prevents signaling of the AT2R.
Nucleus tractus solitarii (nTS) is required for phrenic long term facilitation (pLTF) after acute intermittent hypoxia (AIH)
Authors: Ostrowski Daniela , Kleiber Allison C. , Heesch Cheryl M. , Kline David D. , Hasser Eileen M.
Published: June 2021

Repeated episodes of acute hypoxia lead to pLTF which is thought to involve local mechanisms in the spinal cord. However, carotid body denervation decreases pLTF indicating chemoreceptor afferent input also contributes to pLTF. We hypothesized that the nTS, the first integration site of chemoreceptor afferents, is critical to the generation and maintenance of pLTF. Anesthetized, vagotomized, paralyzed and ventilated male rats were exposed to 10 hypoxic episodes (10% O2, 45sec, 5 min intervals) following bilateral nTS microinjection of aCSF or the GABA receptor agonist muscimol to inhibit nTS activity. After aCSF injection (n=4) integrated phrenic nerve activity increased during hypoxia (567±222% baseline) and amplitude remained elevated ≥1hr after AIH (131±28% baseline). Muscimol injection (2mM; 60nL) prior to AIH blocked increases in phrenic activity during hypoxia (7±14% baseline; n=3) and no LTF occurred (−3±8% baseline). Furthermore, muscimol injections after pLTF induction (130±33% baseline; n=3) decreased phrenic nerve amplitude toward pre‐AIH levels (6±10% baseline; n=3). Results indicate that nTS neuronal activity is required for the development and maintenance of pLTF. HL98602, AvH 1135664
GPER1 agonist improves cerebral microvascular function after hypoxia/reoxygenation injury in male and female rats
Authors: Murata Takahiro , Dietrich Hans H. , Horiuchi Tetsuyoshi , Hongo Kazuhiro , Dacey Ralph G.
Published: June 2021

Estrogen is a known neuro‐ and vaso‐protective agent in experimental cerebral ischemia. Recently, a novel G protein‐coupled estrogen receptor 1 (GPER1) has been identified. We investigated the mechanism of GPER1 mediated vasoreactivity and also its vasoprotective effect after hypoxia/reoxygenation (H/RO) injury. Rat cerebral penetrating arterioles from both genders were isolated, cannulated and pressurized. Vessel diameters were measured. To investigate vasomotor mechanism of the GPER1 agonist (G‐1), several inhibitors were tested. Ischemia/reperfusion (I/R) injury was simulated using H/RO. Vasomotor responses to adenosine tri‐phophate (ATP) after H/RO were measured with or without G‐1. G‐1 produced a vasodilatory response, which was partially dependent on endothelium‐derived nitric oxide (NO) but not arachidonic acid cascades and endothelial hyperpolarization factor. G‐1 treatment after H/RO injury fully restored arteriolar dilation to ATP compared to controls. In conclusion, GPER1 agonist elicited dilation, which partially caused by endothelial NO pathway and induced by direct relaxation of smooth muscle cells. Further, GPER1 agonist restored vessel function of arterioles after H/RO injury and may play an important role in estrogen fs ability to protect the cerebrovasculature against I/R injury. Support: NIH P01 NS32636, NIH R01 HL041250, NIH R01 NS30555, and KAKENHI 24890079.
Analysis of renal ganglioside GM3 distribution in rat models of type 1 and type 2 diabetes
Authors: Bozic Josko , Novak Anela , Kurir Tina Ticinovic , Rezic‐Muzinic Nikolina , Cikes‐Culic Vedrana , Puljak Livia , Ferhatovic Lejla , Markotic Anita , Valic Zoran
Published: June 2021

Ganglioside GM3 is particularly abundant in the kidney tissue and is thought to play an important role in the maintenance of the charge‐selective filtration barrier of glomeruli. Considering the role of GM3 ganglioside in kidney function, the aim of this study was immunohistochemical analysis of renal GM3 distribution in rat models of type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM). Diabetes was induced with streptozotocin (55 mg/kg for T1DM, n=5; and 35 mg/kg for T2DM, n=5) injection to male Sprague‐Dawley rats weighing between 140 and 160 g which were fed with normal pellet diet (T1DM) or high‐fat diet (T2DM). Rats were sacrified two weeks after diabetes induction, frozen renal sections were stained with primary GM3 antibody and visualized by secondary antibody coupled with Texas‐Red. Immunofluorescent microscopy detected 1.7 fold higher GM3 expression in tubules and 1.25 fold higher GM3 in glomeruli of T1DM compared to control group. T2DM rats showed unchanged GM3 in glomeruli, but significant higher GM3 expression in tubules, compared to control animals. Given the known role of GM3 ganglioside in kidney function and our finding of increased tubular GM3 content in both types of diabetes, we could hypothesize the role of GM3 in early pathogenesis of diabetic nephropathy.

This study was supported by Croatian Science Foundation.
Oryeongsan improves diabetes‐associated renal proliferation and fibrosis in cultured rat mesangial cells
Authors: Yoon Jung Joo , Lee Yun Jung , Lee So Min , Lee Yong Pyo , Kim Dae Hwan , Lee Bin , Kang Dae Gill , Lee Ho Sub
Published: June 2021

Diabetic nephropathy (DN) associated with morbidity and mortality of diabetic patients. Mesangial cell proliferation is known as the major pathologic features such as glomerulosclerosis and renal fibrosis. Oryeongsan (ORS), traditional herbal formula, is widely used for the treatment of nephrosis, dropsy, and uremia.

Thymidine incorporation under HG was significantly accelerated, which was inhibited by ORS in a dose dependent manner. Pretreatment of ORS induced down‐regulation of cyclins/CDKs and up‐regulation of CDK inhibitor, p21waf1/cip1 and p27kip1 expression. In addition, ORS reduced HG‐induced RMCs proliferation by suppression of the MAPK phospholyration such as ERK, JNK, and p38. ORS significantly suppressed the HG‐induced ROS production.

HG enhanced expression of □brosis biomarkers such as collagen IV and CTGF, which was markedly attenuated by ORS. Moreover, ORS inhibits HG‐induced fibronectin mRNA expression. ORS decreased TGF‐â1 and p‐Smad2/Smad4 expression, whereas increased Smad7 expression under HG. Thus, ORS promoted ECM degradation through disturbing TGF‐â– SMAD signaling.

Taken together, these results demonstrate that ORS has a protective effect on renal proliferation and fibrosis. These results suggest that ORS might prove to be effective in the treatment of renal dysfunction leading to DN.
Low molecular weight fucoidan against renal ischemia‐reperfusion injury via inhibition of the MAPK signaling pathway
Authors: Zhou Hong , Chen Jihui , Yang Baoxue
Published: June 2021

Ischemia reperfusion injury (IRI) is a leading cause of acute kidney injury (AKI) in both native and transplanted kidneys. As a common pathophysilological cause of acute renal failure (ARF), IRI‐induced AKI occurs in many clinical settings including renal transplantation, shock, and vascular surgery. The objective of the present study was to evaluate whether low‐molecular‐weight fucoidan (LMWF) could attenuate renal IRI in an animal model and in vitro cell models and study the mechanisms in which LMWF protects from IRI. Male mice were subjected to right renal ischemia for 30 min and reperfusion for 24 h, or to a sham operation with left kidney removed. Kidneys undergone IR showed characteristic morphological changes, such as tubular dilatation, and brush border loss. However, LMWF significantly corrected the renal dysfunction and the abnormal levels of MPO, MDA and SOD induced by IR. LMWF also inhibited the activation of MAPK pathways, which consequently resulted in a significant decrease in the expression of cyto‐c, ratios of Bax/Bcl‐2 and cleaved caspase‐3/caspase‐3, and phosphorylation of p53. LMWF alleviated hypoxia‐reoxygenation or CoCl2 induced cell viability loss and ΔΨm dissipation in HK2 renal tubular epithelial cells, which indicates LMWF may result in an inhibition of the apoptosis pathway through reducing activity of MAPK pathways in a dose‐dependent manner. Our findings show LMWF ameliorates acute renal IRI via inhibiting MAPK signaling pathways in vivo and in vitro. This protective effect is attributed to the improvement of renal function, balance of oxidative stress and antioxidative defense and anti‐apoptosis. In summary. the results suggest that LMWF may serve as a potential therapeutic agent for acute renal IRI, and MAPK pathways, especially JNK/p38‐MAPK is an appealing therapeutic target for AKI.
The Protective Role of Suppressor of Cytokine Signaling 3 (SOCS3) Against Angiotensin II‐Induced Endothelial Dysfunction
Authors: Li Ying , Johnson Andrew , Kinzenbaw Dale , Faraci Frank
Published: June 2021

Angiotensin II (Ang II) plays a major role in vascular disease and hypertension, in part, through the interleukin‐6/signal transducer and activator of transcription 3 (IL‐6/STAT3) pathway. Although SOCS3 is a known regulator of this pathway in the immune system, its role in vascular disease and hypertension is unknown. We hypothesized that SOCS3 protects against Ang II‐induced endothelial dysfunction. Responses of carotid arteries from SOCS3 haplodeficient mice (SOCS3+/−) and wild‐type (WT) littermates were examined after 22 hrs incubation with vehicle or Ang II (1 nmol/L). Relaxation to acetylcholine (Ach, endothelium‐dependent) was similar in all arteries incubated with vehicle. This low concentration of Ang II did not affect Ach‐induced vasodilation in WT, but reduced that of SOCS3+/− mice by ~50% (P<0.05). This Ang II‐induced impairment was prevented by co‐incubation with S3I‐201 (a small molecular inhibitor of STAT3) or an anti‐IL‐6 antibody or tempol, a scavenger of superoxide. Responses to nitroprusside were similar in all groups. These data suggest that reductions in SOCS3 expression do not alter vascular function under baseline conditions but predispose to Ang II‐induced endothelial dysfunction. Thus, SOCS3 may normally protect endothelium by inhibiting IL‐6/STAT3 signaling. This work was supported by NIH grants NS24621 and HL62984.
Angiotensin‐II (AngII) hypertension aggravates neurovascular dysfunction in mouse models of Alzheimer's disease (AD)
Authors: Iadecola Costantino , Faraco Giuseppe , Yebenes Ana Moraga , Park Laibaik , Wang Gang
Published: June 2021

Hypertension (HTN), the main cause of vascular cognitive impairment, doubles the risk of Alzheimer's dementia (AD). However, the mechanisms of this effect remain unclear. The amyloid‐β peptide (Aβ), a key pathogenic factor in AD, induces cerebrovascular dysfunction. We hypothesized that HTN, which also alters cerebrovascular function, acts in concert with Aβ to amplify its deleterious cerebrovascular effects. Infusion of AngII (45 min) induced HTN and attenuated the increases in cerebral blood flow (CBF) evoked by whisker stimulation (WS) or the endothelium‐dependent vasodilator acetylcholine (ACh) (p<0.05). Neocortical application of Aβ in mice infused with AngII did not affect the HTN, but attenuated further the CBF responses to WS or ACh (p<0.05). Neocortical application of AngII in Tg2576 mice, in which Aβ is elevated due to expression of mutated amyloid precursor protein, aggravated the cerebrovascular dysfunction observed in these mice (p<0.05). The gradual HTN induced by low‐dose AngII (600ng/kg/min; s.c. ×14days) was comparable in Tg2576 and wild type mice (p>;0.05). We conclude that Aβ does not exacerbate AngII HTN, but amplifies its damaging cerebrovascular effects. The resulting alterations in neurovascular regulation may contribute to the pathogenic interaction between HTN and AD in the development of dementia. (Support: Zenith Award of the Alzheimer's Association)
Exercise‐induced increase in beta‐cell function in type 2 diabetics is dependent on fasting glycemia
Authors: Knudsen Sine Haugaard , Karstoft Kristian , Winding Kamilla , Pedersen Bente Klarlund , Solomon Thomas Phillip James
Published: June 2021

To determine the effect of exercise on beta‐cell function nine type 2 diabetics (T2D; age 62±2 y, BMI 30.3±2.0 kg/m2) with high fasting glucose (HiFG; 10.8±0.8 mmol/l, n=4) and low fasting glucose (LoFG; 6.8±0.6 mmol/l, n=5) were studied. Before and the morning following a 1‐hour treadmill walk (65% HRmax), a hyperglycemic (5.4 mM+basal) clamp was performed combined with infusion of glucagon‐like peptide‐1 (GLP‐1) and a bolus injection of arginine. Arterialised blood glucose was measured every 5 min for adjustments of the glucose infusion rates (GIR; mg/kg/min). Insulin secretion rates (ISR; pmol/min) in response to glucose, GLP‐1 and arginine were deconvoluted from C‐peptide concentrations in acute (0–4 min) and steady state (last 30 min) phase.

Exercise did not alter fasting glucose in HiFG or LoFG and the GIR required to maintain hyperglycemia did not differ between trials. Acute ISRarginine was higher (P<0.05) in LoFG compared to HiFG and further increased by exercise (P=0.06). After exercise ISR in response to glucose, GLP‐1 and arginine was higher (all P<0.05) in LoFG compared to HiFG.

In T2D with LoFG, insulin secretory capacity and the exercise‐induced increase in ISR was higher. This suggests that the beneficial effects of exercise on beta‐cell function may be dependent on fasting glycemia.

EFSD/Amylin Paul Langerhans program grant, The Danish Centre for Strategic Research in Type 2 Diabetes (DD2).
Sex differences in VLDL‐triglyceride kinetics in the basal state and in response to high‐intensity interval exercise
Authors: Tuazon Marc A. , Liou Jesse , Henderson Gregory C.
Published: June 2021

Plasma triglycerides (TG) circulate in the fasted state as very‐low density lipoprotein‐TG (VLDL‐TG) and increase cardiovascular disease risk. Chronic exercise lowers plasma TG but the hypotriglyceridemic effect may be due to acute impacts of single exercise bouts. Thus, our aim was to study the impact of one session of high‐intensity interval exercise (HIIE) on VLDL‐TG secretion. C57BL/6J mice were assigned to time‐matched sedentary control (con), continuous exercise (CE), or HIIE groups matched for pre‐exercise blood [TG]. HIIE was a 30min session of 20 running intervals (30m/min after 3 intervals of increasing speed) of 30s each interspersed by 60s walking periods (5m/min). CE was a distance and duration matched continuous run at 13.7m/min. VLDL‐TG secretion rates were measured on the day of exercise and the day following exercise (D2) in separate sets of mice after injection with an inhibitor of circulating TG degradation. In the basal state (con), females had 17% higher secretion vs. males (p<0.01). In females on D2, secretion was 17% lower in HIIE vs. con (p<0.05) with no difference between CE and con. In contrast, there was no effect of exercise in males. Our results show sex differences in VLDL‐TG kinetics in the basal state as well as in response to exercise and that HIIE is an attractive exercise modality for altering VLDL‐TG kinetics in females.

Funded by the Faculty Research Grant Program, Rutgers University
Effect of FIR athletic apparel on oxygen consumption during exercise
Authors: Worobets Jay T , Skolnik Emma R , Stefanyshyn Darren J
Published: June 2021

Athletic apparel are commercially available that contain fabrics with far‐infrared radiation (FIR) properties. If such apparel are capable of inducing positive physiological effects, then there may be important implications when worn by athletes during exercise. The purpose of this study was to examine whether FIR apparel had an effect on oxygen consumption during cycling at submaximal intensities. Twelve male cyclists completed a submaximal incremental cycling test. Each subject was tested on 4 separate days, twice while wearing a full body Control garment, and twice while wearing a similar garment made out of FIR fabric. Throughout each cycling test, the volume of oxygen uptake was calculated using data obtained from a breathing mask connected to a metabolic analysis cart. At lower cycling intensities, the subjects consumed statistically significantly (p<0.05) less oxygen when wearing the FIR apparel compared to the Control garment, despite performing the same amount of mechanical work. Additional research is required to determine the implication of this effect for training or competing athletes, however the results show that this apparel technology does elicit a physiological effect. Support for this study was provided by Hologenix LLC in collaboration with adidas International. Neither source had a role in study design, testing, or interpretation.
Acute exercise increases monocarboxylate transporter 2 expression in mouse cerebellum
Authors: Hoshino Daisuke , Kitaoka Yu , Setogawa Susumu , Masuda Hiroyuki , Tamura Yuki , Yanagihara Dai , Hatta Hideo
Published: June 2021

It is known that lactate is an oxidizable substrate for metabolic tissues. Monocarboxylate transporter (MCT), a membrane protein, facilitates membrane transport of lactate. MCT1 and MCT2 are main lactate transporters in brain. It was shown that exercise increases acutely MCTs expression in muscles but it is not known in brain. The purpose of this study is to examine whether acute exercise can increase MCT mRNA and protein levels in brain. 8‐wk‐old ICR male mice were randomly divided into there groups, which is pre‐exercise (PRE), 0 h (0h) or 5 h (5h) after 6 h of treadmill running. Except for the PRE group, the mice completed 6 h treadmill running (20 m/min) in which the exercise session consisted of two 3 h of bouts separated by 30 min of rest. Cerebral cortex and cerebellum were rapidly harvested at each sampling time. MCT1 and MCT2 mRNA abundances in cerebral cortex were not altered after 6 h of treadmill running. Conversely, MCT2 mRNA in cerebellum, but not MCT1, was significantly increased by 113% (p<0.05) at 5 h after the exercise. MCT1 and MCT2 protein contents were not altered after the exercise in cerebral cortex and cerebellum, either. These findings suggest that MCT2 in cerebellum may have a key role to maintain energy supply to cerebellum during exercise, but a single bout of exercise was not sufficient to increase the protein in MCT2 of cerebellum.
Relationship between oxygen pulse and echocardiography in heart failure with preserved ejection fraction
Authors: McCue Meghan Cameron , Olson Thomas P , Johnson Bruce D , Snyder Eric M , Borlaug Barry A
Published: June 2021

Purpose

Oxygen pulse (O2 pulse) is often used clinically as a surrogate for stroke volume during cardiopulmonary exercise testing; however, little data exists on the validity of this measure in patient populations (e.g. heart failure with preserved ejection fraction – HFpEF). Therefore, the purpose of this study was to examine the relationship between O2 pulse and stroke volume (SV) measured using an accepted technique, echocardiography, at rest and during exercise.

Methods

Eighteen HFpEF (EF=62±1%) patients and 26 healthy controls (CTL) completed an exercise test on a cycle ergometer. Average measures of oxygen consumption (VO2, metabolic cart), heart rate (HR, 12‐lead ECG), and SV (transthoracic echocardiography) were taken at rest and peak exercise. O2 pulse was calculated as VO2 divided by HR.

Results

O2 pulse was significantly correlated with SV at rest and at peak exercise in CTL (r=0.60 and r=0.55, p<0.05 for both respectfully). O2 pulse was similarly significantly correlated with SV at rest in HFpEF (r=0.58, p<0.05) whereas this relationship demonstrated a trend at peak exercise (r=0.44, p=0.06).

Conclusion

Our results demonstrate a moderate relationship between O2 pulse and SV measured using echocardiography in healthy control participants at rest and during exercise. There is a similar relationship at rest in patients with HFpEF; however, this relationship is less strong during exercise.