bluuebunny/crossref_metadata_2025_split huggingface dataset:
Identifying NMDA receptor subtypes in the ventral respiratory column (847.6)
Authors: Leavitt Lee , Curtice Kigen , Raghuraman Shrinivasan , Teichert Russ , Twede Vernon , Olivera Baldomero 
Published: June 2021

The ventral respiratory column (VRC) is a region in the brainstem shown to control breathing patterns in mammals. Using a mouse model, cells from this region are dissociated, plated and incubated with a dye that indicates changes in cytoplasmic calcium levels. Hundreds of cells are monitored as a diverse set of pharmacological agents are applied. The spectrum of cellular responses provides a profile of the receptors found on each of these neurons. Previously, varieties of cell classes were shown to contain NMDA receptors. However, specific compositions of subunits within these receptors are not known. These receptors are ligand gated ion channels composed of four non‐covalently bound protein subunits. Each subunit has a different response profile determined by interactions of agonist and antagonists. Conantokins (peptides isolated from snail venom) and other compounds afford understanding which NMDA receptor subtypes are present in different cell‐classes. This project has continued to classify the subunit compositions of NMDA receptors with the ultimate goal of defining which NMDA receptor subunits are present in each class. The results indicate that different neuronal subclasses express different NMDA response subtypes. This will provide valuable information on the individual neurons in the networks of the VRC, and will allow for pharmacological interventions to change behavior in this region.Grant Funding Source: Supported by GM48677
Differential role of microRNAs miR‐221/222 and miR‐103/107 in type 2 diabetes and effects of metformin (851.2)
Authors: Upadhyay Rohit , Ding Hong 
Published: June 2021

Background and Aim: Type‐2 diabetes (T2D) is a highly prevalent, progressive disease constituting the major challenge to global health. MicroRNAs (miRNAs) play an important role in regulating physiological processes in diabetes through binding multiple target mRNAs, resulting in gene silencing. In the present study, the primary objective is to explore the role of miR221/222 and miR103/107 in diabetes.Materials and Methods: Mouse microvascular endothelial cells (MMECs) were cultured for 48 hours under conditions designed to mimic the mileu of T2D mice: normal glucose (NG=11mM) and high glucose (HG=40mM). The levels of miRNA221/222 and mir103/107 expression were analysed by real‐time PCR. MMECs were transfected with specific miR inhibitors/ mimics and then cells were exposed to normal/ high glucose in the presence or absence of metformin. The effects of miR expressions on Akt, P‐Akt, c‐kit, eNOS, P‐eNOS and Cav1 protein levels were determined through western blotting.Results: We found that exposure to high glucose increased the expression of miR‐221/222 but decreased the expression of miR‐103/107. Treatment with metformin partially restored HG‐induced expression of miRNAs towards that seen in control, NG, mileau. Furthermore, we observed that protein levels of total eNOS and P‐eNOS decreased in HG in comparison with NG. The eNOS/P‐eNOS protein levels were restored upon inhibition of miR221 but not with miR‐222, miR‐103 or miR‐107, thus indicating correlation of miR‐221 with eNOS signalling. Results were validated by using miR‐221 mimics (overexpression) and known target (c‐kit) of miR221.Conclusion: These findings suggest that miR221 may offer a new therapeutic strategy for treatment of endothelial dysfunction in diabetic patients or may work as a therapeutic modulator.
New insights on endothelial CaMKII in angiotensin II‐induced hypertension (851.6)
Authors: Charbel Chimene , Toussaint Fanny , Blanchette Alexandre , Gillis Marc‐Antoine , Comtois Philippe , Ledoux Jonathan 
Published: June 2021

Angiotensin II‐induced arterial hypertension (AngII‐AH) is associated with an endothelial dysfunction characterized by a Ca2+ dyshomeostasis. Alteration of the delicate balance between reactive oxygen species (ROS) and nitric oxide (NO) then arise. Recent evidences suggest that hypertension stimulates Ca2+ pulsars and CaMKII but the contribution of AngII and the concomitant ROS remains elusive. The aim of this study was to establish a relationship between endothelial Ca2+ pulsars, ROS and CaMKII in AngII‐AH. Acute exposure to high (> 10‐8 M) concentrations of AngII stimulated Ca2+ pulsars and ROS production in high‐speed confocal microscopy. However, lower AngII level (10‐9 M) only increased Ca2+ pulsars frequency, suggesting a role for ROS in the Ca2+ pulsars stimulation. All AngII concentrations induced endothelial CaMKII recruitment within myoendothelial projections. AngII also stimulated NO production, an effect blunted by CaMKII inhibition (KN‐93). Candesartan, an AT1 blocker, partially reduced Ca2+ pulsars stimulation, suggesting roles for both AT receptors. Moreover, an increased in Ca2+ pulsars frequency and ROS production, associated with CaMKII clustering, is also observed in AngII‐AH mice. Our findings shed a new light on hypertension and Ca2+ dyshomeostasis along with their relationships with CaMKII, a key regulator of endothelial function.Grant Funding Source: Supported by CIHR, FRQS, CFI, HSFC and SQHA.
Chronic hypoxia differentially modulates the response of fetal ovine middle cerebral arteries to endothelin‐1 (853.2)
Authors: Silpanisong Jinjutha , Kim Dahlim , Adeoye Olayemi , Thorpe Richard , Pearce William 
Published: June 2021

To better understand how hypoxia‐induced vascular remodeling alters intracellular responses to ET‐1, we hypothesized that chronic hypoxia alters ET‐1 induced phenotypic transformation in arterial smooth muscle cells within the fetal cerebrovasculature. Endothelium denuded middle cerebral arteries (MCA) harvested from term fetuses of pregnant adult sheep kept at sea level or 3820m for 110 days were serum starved for 24h, then cultured 24h with ET‐1 and various kinase inhibitors. Fetal normoxic (FN) MCAs incubated with ET‐1 exhibited decreased colocalization between MLCK and α‐actin compared to control (starved), suggesting a shift of smooth muscle cells (SMCs) from a contractile to a more synthetic phenotype. This appeared to be mediated by multiple intracellular pathways, with PKC playing the largest role in normoxic arteries. Chronic hypoxia attenuated the ET‐1 induced decrease in MLCK and α‐actin colocalization, decreased the effects of PKC inhibitors, but increased the apparent effects of the CaMK‐dependent pathway, on colocalization. Given that plasma levels of ET‐1 were unaltered by chronic hypoxia, these results suggest that chronic hypoxia shifts the coupling of ET‐1 from PKC to CaMK to alter gene expression and thereby influence vascular remodeling.Grant Funding Source: Supported by National Institutes of Health Grants HD‐31266, HL‐64867, and NS‐076945
NPY ő a regulator of hypoxic cerebrovascular remodeling in fetal lambs (853.4)
Authors: Latschaw Kimberly , Adeoye Olayemi , Silpanisong Jinjutha , Kim Dahlim , Williams James , Pearce William 
Published: June 2021

Prenatal, intra‐partum or post partum exposure of a fetus to hypoxia results in structural and functional changes in cerebral arteries, known as remodeling. Sympathetic nerves have been suggested to contribute to this process. Whereas NE is suggested as the major mediator of adrenergic effects, our preliminary experiments show that there is a guanethidine‐resistant (norepinephrine‐independent) component. This study explores the hypothesis that NPY contributes to hypoxic cerebrovascular remodeling in the fetal cerebral circulation. Chronic hypoxia (CH) produced a 254% ↑ in K‐induced tone and a 30% ↓ in stretch‐induced myogenic tone in fresh nerve‐intact fetal cerebral arteries. CH also increased the magnitude of nerve stimulation induced guanethidine‐resistant contractile tone. Immunohistochemistry revealed that CH significantly ↑ cerebrovascular NPY whereas sympathectomy (SANX) ablated this effect. Likewise, Western blot quantification of NPY‐Y1 receptors revealed that CH increased Y1 receptors 73%. Whereas SANX in normoxic tissues had no significant effect, SANX produced a 30% ↓ in Y1 receptors in hypoxic arteries. Together these results suggest that NPY released from sympathetic cerebrovascular nerves contributes to hypoxic remodeling through increased NPY content/release and Y1 receptor density.Grant Funding Source: Supported by NIH Grants HD‐31266 and NS‐076945
Myricetin alleviates postprandial hyperglycemia in rats with diabetes mellitus (854.1)
Authors: Kim Jung‐In , Choi Ha‐Neul , Lee Soo‐Jin , Kang Min‐Jung 
Published: June 2021

Tight control of both fasting and postprandial blood glucose is essential in the treatment of diabetes mellitus. It has been suggested that postprandial hyperglycemia is more strongly associated with the risk of cardiovascular diabetic complications than is fasting hyperglycemia. Myricetin strongly inhibits α‐glucosidase in vitro, suggesting that it could have hypoglycemic activity in vivo. This study investigated the α‐glucosidase inhibitory activity of myricetin in vivo. Streptozotocin‐induced diabetic rat were administered a starch solution (1 g/kg) with and without myricetin (100 mg/kg) or acarbose (40 mg/kg) orally after an overnight fast, and postprandial plasma glucose levels were monitored. The administration of myricetin or acarbose significantly decreased the incremental plasma glucose levels 30‐180 min after a single oral dose of starch (p<0.05). Myricetin or acarbose treatment significantly reduced the incremental areas under the glucose response curve (AUC). The AUC of the myricetin‐treated group was not significantly different from that of the acarbose‐treated group. Therefore, we conclude that myricetin is effective for controlling postprandial hyperglycemia in an animal model of diabetes mellitus.Grant Funding Source: This research was supported by NRF in Korea (2012015763)
Exploring off‐target binding of thiazolidinediones and a novel mechanism for restoring insulin sensitivity (854.2)
Authors: Exner Eric , Hoffmann Brian , Sem Daniel , Greene Andrew 
Published: June 2021

The prevalence of type 2 diabetes mellitus (T2DM) is increasing. As insulin resistance is a major feature of T2DM, this will necessitate the increased use of drugs that restore insulin sensitivity. Thiazolidinediones (TDZs) comprise one such class of drugs and are thought to act through peroxisome proliferator‐activated receptor gamma (PPARγ); however, this mechanism is not completely understood, as neither antagonists nor transcriptional/translational inhibitors of PPARγ abolish the effects of these drugs. Moreover, TDZs have been reported to elicit serious side effects that could be mediated through interactions of TDZs with effectors other than PPARγ. We developed a novel method to determine off‐target binding interactions of drugs, which we applied to TDZs. In addition to interactions that could be related to side effects, we observed affinity for salt‐inducible kinase 2 (SIK‐2), which could represent a novel mechanism of action for the insulin sensitizing effects of TDZs. SIK‐2 impairs insulin receptor signal transduction during conditions of nutrient deprivation by phosphorylating insulin receptor substrate 1 (IRS‐1). This study tests the hypothesis that TDZs prevent SIK‐2 mediated phosphorylation of IRS‐1, thus restoring or preserving insulin sensitivity and outlines a method for utilization of existing, effective molecules to identify novel targets for the development of safer therapeutics.Grant Funding Source: Supported in part by National Heart, Lung, and Blood Institute Grant HL‐082798 to A. S. Greene
Plasma irisin is associated with insulin resistance in men (854.4)
Authors: Huth Claire , Marette André , Tremblay Angelo , Weisnagel S. John , Mauriège Pascale , Lacaille Michel , Joanisse Denis 
Published: June 2021

The hormone irisin has been described as increasing energy expenditure and improving glucose tolerance in mice, yet its potential role in humans remains controversial. Objective: We describe the association between circulating irisin and insulin resistance in men with wide‐ranging fitness levels and metabolic health. Methods: Fifty‐two men aged 34‐53 yrs from 4 groups were compared: sedentary non‐obese controls (BMI<25 kg/m2), sedentary obese (BMI>30 kg/m2), sedentary obese glucose intolerant, and non‐obese highly trained endurance active. All participants were evaluated for fitness (VO2max), anthropometric profile, circulating metabolic profile, insulin resistance (hyperinsulinemic‐euglycemic clamp), and baseline plasma irisin levels (EIA, Phoenix Pharamaceuticals, Inc.). Results: Baseline plasma irisin levels were significantly different between groups (ANOVA p=0.01), being lowest in trained men (1406±382 ng/mL) and highest in metabolically deteriorated glucose intolerant subjects (2040±505 ng/mL). Including all subjects, irisin levels were positively associated with percent body fat (r=0.445, p<0.01), and negatively associated with fitness (r=‐0.369, p<0.01) and insulin sensitivity (M/I, r=‐0.355, p<0.01). The strength of these associations was reduced and lost statistical significance when excluding the active individuals, except for that with insulin resistance, which was slightly increased (r=‐0.413, p<0.01). Conclusion: Plasma irisin levels are associated with decreased insulin sensitivity in men, but the association appears to be influenced by training status.Grant Funding Source: Supported by the CIHR and CRIUCPQ.
Role of E2F transcriptional factor family in hydrogen peroxide regulation of dihydrofolate reductase in endothelial cells (855.5)
Authors: Li Hong , Li Qiang , Siu Kin , Cai Hua 
Published: June 2021

Endothelial nitric oxide synthase (eNOS) uncoupling consequent to a deficiency in eNOS cofactor tetrahydrobiopterin (H4B) is an important mechanism of vascular dysfunction. Our previous work has shown that endothelial hydrogen peroxide (H2O2) overproduction specifically downregulates H4B salvage enzyme dihydrofolate reductase (DHFR), which mediates persistent H4B deficiency, eNOS uncoupling and elevated blood pressure in Angiotensin II‐infused mice. However, detailed molecular mechanisms underlying H2O2 regulation of DHFR in endothelial cells remain unclear. In this study, we found that hydrogen peroxide dose and time dependently downregulated DHFR protein expression and its enzyme activity in bovine aortic endothelial cells (BAECs). The DHFR mRNA levels were also decreased by H2O2, implicating transcriptional regulation. Based on the fact that DHFR promoter contains cis‐acting elements for Sp1 and E2F, we constructed wildtype DHFR promoter reporter construct (WT‐DHFR), and mutant DHFR promoter constructs that were deleted of either Sp1 or E2F binding sites. The dual‐luciferase reporter assay showed that while the promoter activities of both WT‐DHFR and Sp1 deletion mutant remained inhibited by H2O2, deletion of the E2F binding sites completely abolished H2O2 attenuation of DHFR promoter activity. RT‐PCR analyses indicated that H2O2 treatment resulted in marked downregulation of E2F1, E2F7 and E2F8 by 38%, 43% and 82% respectively. Intriguingly, overexpression of E2F1, E2F7 or E2F8 restored DHFR expression in response to H2O2, and cotransfection with E2F1 also significantly increased DHFR promoter activity. In conclusion, these results suggest that DHFR is downregulated by H2O2 in endothelial cells transcriptionally via a E2F‐dependent manner, and that restoration of E2F family‐transcription factor activity is effective in preserving DHFR function under oxidative stress.Grant Funding Source: Supported by NHLBI awards HL077440 (HC), HL088975 (HC) and an AHA EI award 12EIA8990025 (HC)
Resveratrol attenuates endothelium‐dependent cyclooxygenase‐mediated contractile activity in the carotid artery of spontaneously hypertensive rats (855.6)
Authors: Rush James , Denniss Steven , Smith Christopher , Jeffery Andrew , Ford Rebecca 
Published: June 2021

The objective of this study was to determine the chronic and acute effects of resveratrol (RSV) on endothelial function and endothelium‐derived contracting factor (EDCF) signaling using common carotid artery (CCA) isolated from spontaneously hypertensive rats (SHR) and Wistar Kyoto rats (WKY). Acetylcholine (Ach)‐stimulated endothelium‐dependent relaxation in pre‐contracted CCA was impaired in SHR (max. 53±6% vs. 86±6% in WKY) caused by competitive cyclooxygenase (COX)‐mediated contraction at high [Ach]. Chronic (28‐day) treatment in vivo (via drinking water) with a moderate RSV dose (Mod‐RSV, ~0.075 mg/kg/day) was without effect on Ach‐stimulated relaxation, or Ach‐stimulated contraction and associated prostaglandin (PG) production in quiescent CCA, in either strain. In contrast, in SHR but not WKY, a chronic high RSV dose (High‐RSV, ~7.5 mg/kg/day) improved Ach‐stimulated relaxation (max. 99±5% vs. 53±6% in No‐RSV SHR), and attenuated Ach‐stimulated contraction (55±5% vs. 68±5% in No‐RSV SHR) and associated PG production (189±30 vs. 519±93 pg/ml in No‐RSV SHR) (all p<0.05). High‐RSV also reduced mean arterial pressure in SHR (159±6 vs. 176±6 mmHg in No‐RSV SHR; p<0.05). In separate experiments, acute (30 min) in vitro treatment (in‐bath pre‐incubation) with 20µM RSV (RSV‐20µM) nearly abolished Ach‐stimulated contraction and greatly attenuated the associated PG production in SHR and WKY CCA (all p<0.05). Taken altogether, these experiments demonstrate that RSV can reverse endothelial dysfunction caused by EDCF activity by a signaling mechanism predominately involving the attenuation of COX‐derived PG production.Grant Funding Source: Supported by NSERC Canada RGPIN 238342
Impaired renal NCC function and expression: a mechanism driving norepinephrine evoked salt‐sensitive hypertension? (857.6)
Authors: Walsh Kathryn , Wainford Richard 
Published: June 2021

Aim: These studies test the hypothesis that impaired renal NCC regulation is a mechanism underlying the development of norepinephrine (NE) evoked salt‐sensitive hypertension in Sprague‐Dawley (SD) rats.Methods: SD rats receiving a s.c. saline vehicle, NE (600ng/min), DMSO/saline vehicle (50:50), or hydrochlorothiazide (HCTZ 4mg/kg/d) and NE infusion were fed a 0.4% (NS) or high 8% NaCl (HS) diet for 14 days. On day 14, MAP, MAP response to i.v. hexamethonium (30mg/kg) and peak natriuresis to i.v. HCTZ (2mg/kg) infusion was assessed and NCC immunoblotting was performed on kidney cortex tissue.Results: NE significantly increased MAP and vascular sympathetic tone. HS exacerbated NE induced hypertension, induced up‐regulation of NCC protein levels and prevented dietary sodium stimulated reduction in HCTZ evoked natriuresis. HCTZ + NE co‐infusion abolished the salt‐sensitive component of NE induced hypertension.

s.c. saline vehicle
s.c. NE
s.c. DMSO/saline
s.c. NE + HCTZ

NS
HS
NS
HS
HS
HS

MAP (mmHg)
124±2
124±1
151±3Ï•
171±4*â‰
134±4
152±3â‰ ÏˆÏ„

Peak Î”MAP to hexamethonium (mmHg)
‐61±4
‐66±3
‐77±6Ï•
‐81±8â‰
‐57±4.5
‐69±3Ï„

Peak Î”UNaV to HCTZ (Î¼eq/min)
8.7±0.3
7.2±0.7*
11.1±1.1 Ï•
10.8±0.4â‰
6.3±1.3
0.4±0.2 â‰ ÏˆÏ„

NCC expression(ODU/mm2 normalized to GAPDH)
TBD
TBD
0.15±0.02
0.27±0.06*
n.d.
n.d.

*p<0.05 vs respective NS gp; ϕp<0.05 vs vehicle NS gp; ≠p<0.05 vs vehicle HS gp; ψp<0.05 vs DSMO vehicle; τp<0.05 vs NE + HS gp; n=4‐6/gp.Conclusion: These findings reveal that the combination of high salt intake and excess NE evokes the development of salt‐sensitive hypertension which consequently results in impaired NCC function and increased protein expression. These results contrast the established down‐regulation of NCC expression and circulating NE levels observed during high salt‐intake in salt‐resistant rat phenotypes and provides a new insight into the mechanisms underlying the influence of sympathoexcitation on the kidney in hypertension.Grant Funding Source: R01HL107330 & K02HL112718A1
Post‐injury alcohol exposure exacerbates neuroinflammation and impairs neurological recovery following traumatic brain injury (859.6)
Authors: Teng Sophie , Maxi John , Katz Paige , Gilpin Nicholas , Molina Patricia 
Published: June 2021

BACKGROUND: There are ~1.7 million reported traumatic brain injury (TBI) cases in the U.S. annually. Alcohol abuse contributes to 36% to 51% of all TBI incidents, and patients continue to use alcohol after TBI in up to 26% of cases. Limited preclinical studies have examined the impact of post‐injury alcohol exposure on TBI recovery and the underlying mechanisms. The aim of this study was to determine the effect of post‐injury alcohol exposure on TBI outcomes in terms of neuropathological and neurological recovery.METHODS: Male Sprague‐Dawley rats (~300 g) were fitted with a female Luer‐lock over a 5 mm left lateral craniotomy 1 week prior to injury. TBI was induced by lateral fluid percussion (~30 PSI, ~25 ms) under isoflurane anesthesia. At day 4 post‐injury, animals were exposed to either intermittent alcohol vapor (95% ethanol 14h on /10h off) or room air for 10 days. RESULTS: TBI produced immediate apnea (17±5 s) and delayed righting reflex (419±30 s). Neurological severity score (NSS) was increased as a result of injury prior to alcohol exposure (2‐fold; p<0.05). TBI/Air group showed progressive recovery with no significant impairment in NSS detected at 14 and 18 days post‐TBI. In contrast, alcohol exposure impaired recovery and had higher NSS than time‐matched air‐exposed animals throughout the 10 day period of alcohol exposure and following a 4 day abstinence period (3.5‐fold; p<0.05). Alcohol exposure alone increased NSS score after 10 days of vapor, but returned to baseline after 4 days of abstinence. Immunofluorescence revealed increased activation of astrocytes, microglia, and other markers of neuroinflammation in alcohol exposed brains after TBI.CONCLUSIONS: These findings indicate that alcohol exposure impairs neurological recovery, which may be caused by sustained neuroinflammation. The clinical implications of long‐term consequences in TBI patients exposed to alcohol during recovery warrant further investigation.Grant Funding Source: Supported by NIAAA‐AA7577, F30AA022838
Progesterone supplementation improves blood pressure and uterine artery resistance and hypoxia‐stimulated placental cytokines during pregnancy (860.16)
Authors: Amaral Lorena , Kipprono Luissa , Wallace Kedra , Frazier Krystal , Moseley Janae , Martin James , LaMarca Babbette 
Published: June 2021

Preeclampsia (PE), new onset hypertension at 20 weeks of gestation, is characterized by increase uterine artery resistance (UARI), elevated TNF‐α, IL‐6, IL‐17, and sFlt‐1. We have demonstrated that PE women have significantly lower circulating progesterone (P) than normal pregnant (NP). Therefore, we hypothesized that progesterone (17‐OHP) supplementation could improve blood pressure and decrease UARI and inflammatory cytokines during PE. To address this question we examined the effect of intraperitoneally administered 17‐OHP (3.32mg/kg) on blood pressure (MAP) and UARI in the RUPP rat model of PE. In addition, we examined hypoxia‐stimulated cytokines secreted from placenta explants collected from NP subjects treated at UMMC via ELISA. MAP in NP rats (n=13) was 92+2; 123+2 in RUPP (n=18), and 116 +1 mmHg in RUPP+17‐OHP (n=10), p <0.05. UARI was 0.78+0.03 in RUPP (n=4) and 0.63+0.038 in RUPP+17‐OHP (n=8), p <0.05. Hypoxic placental TNF‐α, IL‐6, IL‐17, and sFlt‐1 was 2.9+1.0, 53 +27, 7.3+4, 1038+362 which was blunted with 1 uM progesterone to 1.8+7, 33+7, 5+1.5 and 623+133 pg/ml. In conclusion, progesterone supplementation improves UARI and hypertension and hypoxia‐stimulated cytokines during pregnancy.Grant Funding Source: Supported by Obstetrics and Gynecology, University of Mississippi Medical Center