bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nrf2 transcription factor inhibition aggravates oxidative stress induced D1R dysfunction and hypertension in mice
Authors: Farooqui Zeba , Lokhandwala Mustafa F. , Banday Anees Ahmad 
Published: April 2020

The renal dopamine 1 receptor (D1R) dysfunction is strongly associated with oxidative stress and high blood pressure (BP). Nuclear factor E2‐related factor 2 (Nrf2), a redox‐sensitive transcriptional factor is a key regulator in antioxidant response element (ARE)‐mediated induction of phase II antioxidant enzymes. The present study was conducted to investigate the role of Nrf2/ARE signaling pathway in renal D1R function and BP in mice. C57BL/6J mice were treated with a pro‐oxidant buthionine sulfoximine (BSO) (10 mmol/L in drinking water) and ML385, a Nrf2 inhibitor that binds to Nrf2 and inhibits its downstream target gene expression (10 mg/kg body weight/day, intraperitoneally through osmotic pumps) for 8 weeks. BSO administration to wild type mice resulted in marked increased in oxidative stress and mean arterial pressure (MAP) which was accompanied by decreased renal D1R expression and glomerular filtration rate (GFR). Also, SKF38393 (D1R agonist) infusion failed to promote sodium excretion indicating D1R dysfunction in BSO treated animals. ML385 treatment per se had no significant change in MAP, D1R, heme oxygenase‐1 (HO‐1) and NADPH quinone oxidoreductase1 (NQO‐1) expression, GFR and sodium excretion. However, co‐treatment of ML385 and BSO exhibited robust increase in MAP, aggravated oxidative damage and significantly decreased GFR. ML385 treatment to BSO administered animals further impaired the D1R function that resulted in decrease in sodium excretion. Moreover, ML385 and BSO co‐treatment showed decreased D1R and phase II antioxidant enzyme (HO‐1 and NQO‐1) expression in comparison to BSO alone animals. In conclusion, the results suggest Nrf2 inhibition exacerbated oxidative stress induced D1R dysfunction and hypertension possibly by attenuating the phase II antioxidant defense response.Support or Funding InformationThis work is funded by National Institutes of Health (National Heart, Lung, and Blood Institute) Grant HL‐139808.
Post‐partum Anxiety and Hypertension, but not Chronic Neuroinflammation Occur in Response to Hypertensive Pregnancies
Authors: Robinson ReAnna , Bowles Teylor , Solis Lucia , Dumas John P. , Spencer Shauna-Kay , Griffin Ashley , Shaffery James P. , Wallace Kedra 
Published: April 2020

During pregnancy hypertensive related disorders, such as preeclampsia and HELLP syndrome, are associated with systemic inflammation and changes in the central nervous system. Previous clinical and experimental studies have shown that circulating inflammatory factors in the blood can contribute to blood brain barrier (BBB) damage in some women with these conditions, which could serve as one possible explanation for the alterations in post‐partum behavior. Using two animal models of hypertensive pregnancy (preeclampsia vs HELLP) we tested the hypothesis that T cell activation during a hypertensive pregnancy is associated with post‐partum anxiety and chronic neuroinflammation.On gestational day (GD) 12 mini‐osmotic pumps infusing sFlt‐1 (4ug) and sEng (7ug) were placed into rats to induce HELLP or with sFlt‐1 alone to increase blood pressure. A subset of rats had 2mg/kg of Orencia infused on GD13 to decrease T cell activation. All rats delivered on GD21 and beginning postpartum week (PPW) 6 animals completed open field and zero maze testing. Blood pressure was measured via tail cuff and animals were euthanized. At euthanization brains were collected, sectioned into frontal and posterior cortices, brainstem and cerebellum. T cells and microglia were isolated from the posterior cortex and brainstem through enzymatic and microbead isolations. Cell populations were cultured overnight and assayed for inflammatory markers via ELISA. Data was analyzed via ANOVA with Tukeys multiple comparison test for post‐hoc analysis using Graphpad Prism.All rats spent significantly less time in the open field compared to NP control rats (p<0.0001). Orencia treatment did not significantly increase the time spent in the open field compared to untreated rats (p=0.18). Both HELLP (p=0.005) and NP+sFlt‐1 (p=0.0005) rats spent significantly less time in the open sections of the zero maze compared to NP rats. However, this behavior was reversed with Orencia treatment (p=0.223). MAP was significantly increased in HELLP rats (p<0.01) and hypertensive rats (p=0.02) compared to NP rats. Orencia prevented hypertension in HELLP (p=0.01) and hypertensive rats (p=0.004) compared to the untreated rats. There were not any significant differences in IL‐17 (p=0.25 brainstem, p=0.89 posterior cortex) or TNF‐alpha (p=0.45 brainstem, p=0.11 posterior cortex) secretion between any of the brain regions or groups when analyzed via ELISA.The results from the current study suggest that hypertension and T cell activation during pregnancy contributes to changes in post‐partum anxiety and post‐partum hypertension but not chronic neuroinflammation. Future studies will examine cognition and look at additional inflammatory pathways.Support or Funding Information1R01MH116027‐01A1
Changes in Bone Strength and Distal Femur Trabecular Thickness following Sleep‐Deprivation in Ovariectomized Rats Treated with Zoledronate
Authors: Nolte Erin , Frisch Frank 
Published: April 2020

Osteoporosis is a disease that causes the density and quality of bone to be decreased, which can increase the risk of fracture. As bone is not a homogeneous tissue and bone mineral density (BMD) is a crude evaluation of the architectural changes seen in osteoporosis, the trabecular thickness may serve as a better single evaluation of bone health. 1 in 3 women over the age of 50 will be affected by osteoporosis. This study aimed to show how bone strength and distal femur trabecular thickness might be affected by sleep‐deprivation in estrogen‐deficient rats. Secondarily, we wanted to evaluate if Zoledronate would attenuate the deleterious consequences of sleep‐deprivation on bone. Wistar female rats were ovariectomized to contrive post‐menopausal estrogen‐deficiency. The rats were separated into 4 groups. The control group (C, n=4) was given an intraperitoneal (IP) injection of 0.45 mL of 0.9% saline, were housed in standard conditions permitting 12 hours light and 12 hours dark. The Zoledronate group (Z, n=8) were given an IP injection of 50 ug/kg of 10% Zoledronate and housed in standard conditions with a 12 hour light/dark cycle. The sleep‐deprived group (SD, n=8) were given the same IP injection as the rats in C, but were housed in chambers that did not permit sleep for 18 hours, then moved to sleep chambers for 6 hours. The sleep‐deprived Zoledronate group experienced the same sleep deprivation as the SD group, but received an IP injection of 50ug/kg body weight of 10% Zoledronate. After 5 weeks, tibiae and femora were harvested, wrapped in saline‐soaked gauze, and stored at −80F until a 3‐point bending test, high‐resolution micro‐CT and peripheral computed tomography was done. The SDZ group showed improved bone strength compared to the SD group (165.97 N and 162.21 N, respectively; N.S.). Also, the SDZ group showed improved distal femur trabecular thickness compared to the SD group (75.5 microns and 68.375 microns, respectively; p<0.05). The value of bisphosphonates in bone preservation is well documented. We attempted to illuminate the value of a bisphosphonate in sleep‐deprived environments in the hopes of evaluating the efficacy and potential therapy for executive women who consistently work in sleep‐deprived states. Our findings are equivocal but encouraging to pursue studies of a longer duration.Support or Funding InformationSpecial thanks to the Novartis Pharmaceuticals Corporation for trabecular thickness analyses.
Reduced responsiveness of bone marrow hematopoietic cells to sympathetic activation is protective against high fat diet‐induced obesity and gut dysbiosis
Authors: Ahmari Niousha , Geis Natalie M. , Singh Arashdeep , de Lartigue Guillaume , Zubcevic Jasenka 
Published: April 2020

INTRODUCTIONGenetic ablation of beta 1 and 2 receptors in the bone marrow (BM) results in mild immunosuppression and beneficial shifts in the gut microbiota. Considering the role of sympathetic activity, inflammation and gut dysbiosis in obesity, we hypothesized that reduction of BM responsiveness to sympathetic activation will dampen the deleterious effects of high‐fat diet (HFD) via protective host‐microbiota interaction.METHODSChimera BM mice were generated by reconstituting sub lethally‐irradiated C57BL/6J mice with whole BM cells from either the beta‐adrenergic 1/2 receptor knock down (BM C57‐Adrb1.b2 KD) or C57BL/6J mice (BM C57‐C57). Circulating T cells, monocytes, and macrophages were measured at baseline. Both groups of mice were randomized to either control (ND, 10% kcal fat, n=4/5 per group) or high‐fat diet (HFD, 60% kcal fat, n=5/6 per group) ad libitum for two weeks. Body weights and food intake were monitored throughout the study. Magnetic resonance imaging was used to determine body composition and fat to muscle ratio. Visceral fat pads were weighed, and relative abundance of major gut bacterial phyla were determined using qPCR at endpoint.RESULTSBM C57‐Adrb1.b2 KD mice were protected from obesity‐related outcomes such as increased total weight gain, total body fat to muscle ratio, and visceral fat pad weight, all of which were all present in the BM C57‐C57 mice on HFD (P<0.05 vs ND). Interestingly, no difference in the food intake was observed between the experimental groups. BM C57‐Adrb1.b2 KD chimera also presented with lower circulating inflammatory Ly6C+ monocytes compared to the BM C57‐C57 chimera mice (p<0.05), prior to HFD feeding. Notably, BM C57‐Adrb1.b2 KD chimera were also protected from HFD‐dependent alterations in major bacterial phyla such as Firmicutes and Actinobacteria, compared to the BM C57‐C57 chimera in which the same phyla were significantly altered by HFD (P<0.05 vs ND).CONCLUSIONThese data demonstrate that the BM C57‐Adrb1.b2 KD mouse, characterized by reduced responsiveness of BM hematopoietic cells to sympathetic activation, is protected against obesity possibly via mechanisms involving reduction in pro‐inflammatory monocytes and protection against alteration in the specific gut bacterial phyla.
Iron and copper transport activities of the mammalian metal‐ion transporters DMT1 and CTR1
Authors: Azucenas Corbin R. , Shawki Ali , Logeman Brandon L. , Niespodzany Eric J. , Dunham Justin L. , Ruwe T. Alex , Thiele Dennis J. , Mackenzie Bryan 
Published: April 2020

Divalent metal‐ion transporter‐1 (DMT1) and the high‐affinity copper transporter‐1 (CTR1) play essential roles in the intestinal absorption of iron and copper respectively. Both transporters are potential therapeutic targets in disorders of metal metabolism. Disagreement remains over whether the metal‐ion specificities of the two transporters overlap. For example, others have concluded that DMT1 transports Cu+ and CTR1 transports Fe2+ based on the results of shRNA knockdown of gene expression in Caco‐2 cells [Espinoza A et al (2012) Biol Trace Elem Res 146, 281]. Since these observations contradicted our published data regarding the substrate profile of DMT1 in vitro [Illing AC et al (2012) J Biol Chem 287, 30485] and in vivo [Shawki A et al (2015) Am J Physiol Gastrointest Physiol 309, G635] or of CTR1 in vitro [Lee J et al (2002) J Biol Chem 277, 4380], we have re‐examined metal‐ion transporter substrate profiles. We tested the hypothesis that DMT1 can transport copper and that CTR1 can transport iron by using radiotracer assays and the voltage clamp in RNA‐injected oocytes expressing human DMT1 or CTR1. Expression of CTR1 in oocytes stimulated up to 20‐fold the uptake of 2 μM 64Cu+ (pH 5.5) but did not stimulate the uptake of 64Cu2+ or 55Fe2+. Expression of DMT1 in oocytes stimulated 80‐fold the uptake of 2 μM 55Fe2+ (pH 6.0) but transport of 64Cu+ or 64Cu2+ did not differ from that in control oocytes. We found that Cu+ inhibited DMT1‐mediated 55Fe2+ uptake in a competitive fashion (Ki ≈ 58 μM). In DMT1‐expressing oocytes, Cu+ evoked inward currents; however, such currents were also observed in control oocytes and their I/V relationships did not resemble those for DMT1 substrates Fe2+ and Cd2+. Addition of Fe2+ or Cd2+ abolished the presteady‐state (transient) currents observed in the absence of metal ion whereas addition of Cu+ or Cu2+ did not. We found, however, that Cu2+ accelerated the decay of the transient currents. We conclude that (1) whereas Cu+ and Cu2+ are capable of interacting with DMT1, neither are transported substrates; and (2) CTR1 mediates transport of Cu+ but not of Cu2+ or Fe2+. We therefore find no evidence of overlapping metal‐ion specificities in DMT1 and CTR1.Support or Funding InformationPHS grants R01‐DK080047, R01‐DK107309, R01‐DK074192, and R25‐HL115473; and the American Physiological Society
Identifying Direct Interactions Between the Rho GTPase TCL and Coronin CRIB Motifs
Authors: Murphy Rachel E. , Samuelson Chelsea A. , Hamann Michael J. 
Published: April 2020

TCL is a Rho GTPase that contributes to tumor‐associated angiogenesis and metastatic melanoma; however, less is known about its basic cell biology and biochemistry. Currently, our lab has found that GTP‐loaded TCL tends to localize to the plasma membrane, while GDP‐loaded TCL localizes to intracellular vesicles. Our data also suggests that vesicle localization of GDP‐loaded TCL occurs through a protein/protein interaction. Coronins are a logical partner for this interaction as they bind to other Rho GTPases when they are in a GDP‐loaded form. To test for a direct interaction between Coronins and TCL, the CRIB domains from the seven human Coronin isoforms have been cloned into plasmids for use in interaction assays using both traditional GST‐fusion protein precipitation and protein complementation using an in vitro split luciferase assay system. Given the importance of TCL in angiogenesis and melanoma, delineation of its interactions with partner proteins is essential for understanding its role in pathology‐related processes.Support or Funding InformationThis work was supported by Bemidji State University Biology Department and the College of Business, Mathematics, and Science. Support was also provided through the Neilson Foundation, Bemidji, MN and Regenerative Medicine Minnesota (RMM‐2017‐EP‐04).
Myo‐Inositol Improves Ischemic Stroke Outcome After both Nicotine Containing Electronic Cigarette and Tobacco Smoke Exposure
Authors: Villalba Heidi , Vaidya Bhuvaneshwar , Cucullo Luca , Abbruscato Thomas J. 
Published: April 2020

Ischemic stroke occurs in 87% of all strokes and is the leading cause of disability in the United States. Smoking has been shown to increase brain edema after ischemic stroke and worsen long‐term clinical outcomes. Electronic nicotine delivery systems or e‐cigarettes (e‐Cigs) are gaining popularity over traditional tobacco smoke cigarettes, and have been reported influence stroke outcome. Previous work from our lab reported nicotine and e‐Cig exposure decreased glucose utilization in the brain in ischemic stroke models, further exacerbating the effects of ischemic injury. Myo‐inositol(MI), a major organic osmolyte that promotes cell membrane stability and various cellular functions, has been reported to reduce infarcted area and edema ratio in a diabetic ischemic mouse model. We also sought to understand the role of MI protection with regard to additional stroke comorbidities, such as e‐Cig or tobacco smoke exposure. In this study, we investigated the neuroprotective role of MI transporters during stroke and post‐stroke outcomes, especially related to the role of glial cells and post‐stroke reorganization. We hypothesize MI plays a role in increased recovery of motor function, after stroke, in animal groups exposed to tobacco smoke or e‐Cig vape. Primary astrocytes and primary neurons were used for in vitro studies and a middle cerebral artery occlusion (MCAO) mouse model for in vivo stroke studies. Immunocytochemistry (ICC) studies showed astrocytes express sodium dependent myo‐inositol transporter 1 (SMIT1) and sodium‐dependent glucose transporter 6 (SGLT6). Our data illustrated expression of both transporters increased in a time‐dependent manner during oxygen‐glucose deprivation (OGD), in tobacco smoke extract (TSE), and e‐Cig extract (ECE) treated cells. Further, this was confirmed by an increase of MI uptake in TSE treated astrocytes. Altered cell mitochondrial respiration levels were observed in astrocytes and neurons incubated for 24hr with TSE and ECE followed by OGD exposure using Seahorse XF Cell Mito Stress. Animal studies demonstrated post‐stroke administration of MI, reduced infarction size and edema ratios in tobacco smoke compared to non‐tobacco smoke animals. An improvement of motor function was also seen in selected behavioral tests. E‐cig exposed animals had a slight increase in infarction size compared to non‐e‐Cig animals. This preliminary data suggest myo‐inositol may have a neuroprotective role in ischemic stroke injury and could significantly improve stroke outcome in both tobacco smokers and e‐Cig users. Further investigation will include assessment of sex differences with regard to the neuroprotective mechanisms of MI in e‐Cig and tobacco smoke exposed animals.Support or Funding Information1R01DA0497375 and R01DA029121 to TJA and LC
The Potential Impact of Discrete Action Potentials on Resting Sympathetic Vascular Transduction in Humans
Authors: Cloud Jane N. , Young Benjamin E. , Greaney Jody L. , Shoemaker J. Kevin , Fadel Paul J. 
Published: April 2020

The sympathetic nervous system dynamically regulates blood pressure (BP), primarily through the modification of peripheral vascular tone. Our lab has developed a methodology for quantifying resting sympathetic vascular transduction wherein bursts of muscle sympathetic nerve activity (MSNA) act as a trigger and ensuing changes in BP and vascular conductance are signal‐averaged over the subsequent 15 cardiac cycles to produce characteristic (mean) responses. These previous investigations have focused on the effect of net sympathetic outflow (e.g, burst sequences and burst amplitudes) on the pressor and vascular conductance responses to spontaneous bursts of MSNA. The recent development of methods to identify sympathetic action potentials (APs) to obtain further information regarding sympathetic control of the circulation has led us to begin to examine the potential role that discrete sympathetic APs may play in determining the BP and vascular responses following spontaneous bursts of MSNA. Herein, we compared BP and leg vascular conductance responses between MSNA bursts containing small (i.e., common) or large (i.e., uncommon) APs within quartiles of MSNA normalized to burst amplitude. We hypothesized the presence of large APs in a burst of MSNA would elicit a greater pressor response and a larger decrease in leg vascular conductance. Resting MSNA (microneurography), beat‐to‐beat BP (finger photoplethysmography), and femoral artery blood velocity (Doppler ultrasound) were collected for 10–20 minutes in 5 young healthy adults. Leg vascular conductance index was calculated (LVCi=femoral artery blood velocity/mean arterial pressure). MSNA bursts were sorted into normalized amplitude quartiles (Q1=smallest 25% of bursts; Q4=largest 25% of bursts), and APs were extracted using a matched wavelet methodology. Within Q4, there was no difference in the peak BP or LVCi responses to bursts containing small APs when compared to bursts containing large APs (Δ6±3 small vs. Δ6±2 large mmHg, p=0.74; Δ0.95±2.0 small vs. Δ0.87±1.7 large ml·min−1·mmHg−1, p=0.59). To account for the potential contribution of MSNA bursts occurring in consecutive sequence, we next isolated singlet bursts (separated by ≥1 cardiac cycle lacking MSNA bursts). Within Q4, there was again no difference in the peak BP or LVCi response to singlet bursts containing small APs compared to singlet bursts containing large APs (Q4: Δ7±3 small vs. Δ6±2 large mmHg, p=0.42; Δ0.05±0.07 small vs. Δ0.17±0.11 large ml·min−1·mmHg−1, p=0.08). These preliminary data suggest that the presence of large APs does not appear to translate to greater pressor or decreased leg vascular conductance responses following a spontaneous burst of resting MSNA.Support or Funding InformationFunded by the UTA College of Nursing and Health Innovation and Natural Sciences and Engineering Research Council of Canada
The soluble form of the prorenin receptor disturbed glucose/insulin homeostasis and leptin secretion in obese male mice
Authors: Poupeau Audrey , Gatineau Eva , Yiannikouris Frederique 
Published: April 2020

Obesity is one of the major causes of the rise in prevalence of the metabolic syndrome and hypertension. We recently found that the circulating form of the prorenin receptor (sPRR) increased during the development of obesity. Interestingly, in high‐fat fed C57BL/6 male mice, the infusion of sPRR increased systolic blood pressure through an impairment of the baroreflex sensitivity and the increase in the sympathetic tone, potentially mediated by a leptin‐dependent mechanism. In the present study, we aim to address the contribution of sPRR to the development of the metabolic syndrome in obesity.We first investigated whether sPRR plays a role in glucose and insulin (G‐I) homeostasis. C57BL\6 male mice were fed a high fat (HF) diet for 16 weeks. On week 17 of HF feeding, mice were implanted with an osmotic pump infused for 4 weeks with saline (Veh, N=7) or sPRR (mouse recombinant sPRR‐HisTag, 30 μg/kg/day) (sPRR, N=7). After 12 days of infusion, fasting glucose were examined and intraperitoneal glucose and insulin tolerance tests were performed. Fasting glucose levels were significantly higher in HF‐fed mice infused with sPRR compared with HF‐fed mice infused with vehicle (Glucose: Veh: 180±8 mg/dl; sPRR: 205±5 mg/dl. P<0.05). In addition, HF‐fed mice infused with sPRR exhibited impaired glucose tolerance compared with HF‐fed mice infused with vehicle (area under the curve: Veh: 27143 ± 3210; sPRR: 34702±4191. P<0.05). Despite a higher glucose levels after insulin injection, HF‐fed mice infused with sPRR had a similar reduction in blood glucose in response to insulin compared with HF‐fed mice infused with vehicle. Interestingly, the phosphorylation levels of hepatic Akt decreased significantly in HF‐fed mice infused with sPRR compared with vehicle (p‐Akt/Akt ratio: Veh: 1.0±0.1, sPRR 0.4±0.1 AU, P<0.05) suggesting that sPRR might impair hepatic insulin sensitivity. Downstream glucose and lipid metabolic pathways are currently under investigation in liver and peripheral tissues.Since circulating leptin were elevated in HF‐fed mice infused with sPRR, we next aimed to determine the relative contribution of sPRR to leptin secretion. In vitro studies demonstrated that leptin secretion increased significantly in differentiated 3T3‐L1 cells treated with sPRR compared with cells treated with vehicle indicating that sPRR directly stimulated adipocyte release of leptin and could participate to leptin resistance in obesity.Together our data indicated that sPRR likely worsen the metabolic syndrome by affecting G‐I homeostasis and by stimulating leptin secretion.Support or Funding InformationThis work was supported by National Institutes of Health Grants [R01‐HL‐142969]; the American Heart Association [13SDG17230008]; the National Institute of General Medical Sciences [P30 GM127211]; and the University of Kentucky, Center for Clinical and Translational Sciences [UL1TR001998].