bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Decrease in Tregs Exacerbates DOCA‐Salt Hypertension and Renal Injury in Female Rats
Authors: Belanger Kasey Marie , Gillis Ellen , Musall Jaqueline , Sullivan Jennifer 
Published: June 2021

BackgroundT regulatory cells (Tregs) have previously been shown to protect against increases in blood pressure (BP) in male experimental models of hypertension, however less is known regarding the role of Tregs in BP control in females. Our lab has previously reported that there is a sex difference in the renal T cell profile in DOCA, where DOCA results in a decrease in Tregs in males while females maintain their Tregs. The current study tested the hypothesis that Treg maintenance attenuates the increase in blood pressure (BP) to DOCA‐salt in females.MethodsFemale (n=4–7) 13‐week‐old Sprague Dawley rats underwent an uninephrectomy followed by the implantation of a time release 200mg Deoxycorticosterone Acetate (DOCA) pellet and 0.9% saline to drink ad libitum. Rats were then randomized to receive a vehicle or anti‐CD25 injection (IP 250 μg/week) weekly for 3 weeks and BP was measured by telemetry. 24‐hour urinary protein excretion was measured via Bradford Assay at baseline and weekly thereafter for the duration of the study. At the end of the study, kidneys were isolated for flow cytometric analysis of T cells and a terminal plasma sample was collected to measure the kidney injury marker Tim1/Kim1.ResultsAnti‐CD25 injections in DOCA hypertensive females significantly decreased renal (4.2 ± 0.6 vs. 6 ± 0.7; p=0.03) and circulating Tregs compared to DOCA alone (3.6 ± 0.5 vs. 5.5 ± .6 p=0.05). 3 weeks of DOCA‐salt treatment significantly increased BP (101 ± 3 to 160 ± 5; p=<.0001), and decreasing Tregs exacerbated the DOCA‐salt induced increase in BP (109 ± 1 to 188 ± 4; p=0.002). We calculated area under the curve for each BP tracing, and the overall BP load in the rats treated with anti‐CD25 was significantly greater than in rats with DOCA‐salt alone (3327 ± 37 vs. 3662 ± 39; p=0.033). DOCA‐salt also increased urinary protein excretion from baseline to week 3 (3 mg/day ± 0.4 to 34 mg/day ± 9; p=0.01) and this increase was exacerbated with anti‐CD25 treatment (2 mg/day ± 0.5 to 86 mg/day ± 17; p=0.003). Tim1/Kim1 was also increased in DOCA hypertensive females compared to uninephrectomized controls, and this increase was greater in rats treated with anti‐CD25 (control: 292 ± 25 pg/ml; DOCA: 415 ± 57pg/ml; DOCA+anti‐CD25: 589 ± 105; p=0.04).DiscussionOur data suggests that the maintenance of Tregs in DOCA‐salt hypertensive females attenuates increases in BP and renal injury. Future studies will determine if this effect if mediated by the anti‐inflammatory and anti‐hypertensive effects of IL‐10.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Effects of Dexamethasone Therapeutic Doses Treatment in Electrocardiographic Abnormalities and Cardiac Remodeling of Rats: Role of Oxidative Stress
Authors: Macedo Fabricio Nunes , Souza Diego Santos , Santos João Eliakim Araújo , Vasconcelos Carla Maria Lins , Silva‐Filha Elizabete Santos , Quintans‐Júnior Lucindo José Santos , Mesquita Thassio Ricardo Ribeiro , Santana‐Filho Valter Joviniano 
Published: June 2021

Dexamethasone is the most clinically used glucocorticoid with an established role in the treatment of a wide spectrum of inflammatory‐related diseases. While the therapeutic actions are well known, dexamethasone treatment causes a number of cardiovascular side effects, which are complex, frequent and, in some particular cases, clinically unnoticeable. Thus, we investigated whether a therapeutic regimen of dexamethasone affects cardiac arrhythmogenesis and/or promote cardiac remodeling, focusing on the contribution of reactive oxygen species (ROS). Male Wistar rats were treated with dexamethasone (2 mg/kg, i.p.) for 7 days. Afterward, hemodynamic measurements, autonomic modulation, left ventricular function, cardiac fibrosis, superoxide (O2·−) generation, superoxide dismutase (SOD) activity, lipid peroxidation (TBARS) and arrhythmias were evaluated. Here, we show that dexamethasone increases blood pressure, associated with enhanced cardiac and vascular sympathetic modulation. Moreover, a marked increase in the cardiac O2·− generation was observed, whereas the enhanced SOD activity did not prevent the higher levels of lipid peroxidation in dexamethasone group. Although preserved ventricular contractility and β‐adrenergic responsiveness, we found that dexamethasone‐treated rats display greater interstitial and perivascular fibrosis than control. Besides that, despite the absence of arrhythmias at basal condition, we demonstrated by in vivo and ex vivo approaches that dexamethasone‐treated rats are more susceptible to develop harmful forms of ventricular arrhythmias, when challenged with pharmacological drugs or burst pacing‐induced arrhythmias. Notably, concomitant treatment with apocynin, an inhibitor of NADPH oxidase, prevented these ectopic ventricular events. Taken together, our data revealed that the dexamethasone treated rats were hypertensive and their hearts become arrthymogenic, in addition, our results uncover the pivotal role of ROS‐generating NADPH oxidases in the arrhythmias vulnerability.Support or Funding InformationFapitec/SE ; CAPES ; CNPq and Estácio UniversityThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Transcription Factor HNF4A Regulates Urate Transporter ABCG2
Authors: Kuhns Victoria Lea Halperin , Lewis Raychel , Marten Jonathan , Vitart Veronique , Tin Adrienne , Consortium CKDGen , Köttgen Anna , Woodward Owen M 
Published: June 2021

Elevated urate levels in the serum can contribute to the development of many diseases, including gout, the most prevalent form of inflammatory arthritis. Our previous work identified ABCG2 as a key urate transporter of the kidney and gut epithelium and its dysfunction significantly increases risk of hyperuricemia and gout. A new collaborative meta analysis of genome wide association studies, integrating the results from 457,690 individuals, identified 183 loci associated with serum urate. A further analysis of associated loci to identify independent and potentially causal variants created a credible set of variants for experimental follow up including variants in ABCG2, HNF1A, and HNF4A. HNF1A and HNF4A are transcription factors that are key regulators of liver, renal, and gut transport proteins. Here we sought to examine if HNF1A or HNF4A regulated the expression of ABCG2, and the effects of the identified HNF1A and HNF4A missense variants. To determine any direct regulation of ABCG2 by HNF1A or HNF4A, we used a luciferase assay reporter system where the ABCG2 promoter was used to drive expression of a luciferase reporter. HEK293T cells were co‐transfected with this ABCG2 construct, and plasmids expressing either HNF1A or HNF4A, as well as a GFP reporter used to determine cell number and transfection efficiency. HNF4A increases expression of ABCG2 driven luciferase in a dose dependent and significantly reproducible manner. No increase is observed with either HNF1A co‐transfection, or in the empty vector negative control. Next, the missense mutations were examined in the same luciferase assay for both HNF1A (A98V) and HNF4A (T139I). HNF4A‐T139I demonstrated an increase in ABCG2 luciferase expression to a significantly greater extent than the wild‐type protein, again in a dose dependent and reproducible manner. The increased ABCG2 promoter activation observed with the HNF4A‐T139I was not attributable to increased abundance of the mutant protein. In addition, the HNF4A‐T139I amino acid resides in an area critical for interacting with target DNA promoter regions. Our findings that HNF4A‐T139I is a gain of function variant resulting in increased abundance of ABCG2, the primary secretory transporter, is consistent with our observation that this variant associates with decreased serum urate levels in humans. Thus, we conclude that HNF4A is likely directly regulating expression of ABCG2, and thereby influencing serum urate levels.Support or Funding InformationNIDDK R01DK114091This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Adaptation to K+ deficiency in mouse: coordinate regulation of muscle and kidney electrolyte transporters
Authors: McFarlin Brandon E , Chen Yuhan , Madhur Meenakshi S , Ralph Donna L , McDonough Alicia A 
Published: June 2021

Our previous work in rats subjected to K+ deficient diets demonstrated that K+ shifts from muscle intracellular fluid (ICF) stores to extracellular fluid (ECF) compartment in order to buffer the fall in ECF K+ due to finite losses in urine and feces. The aim of this study was to determine the coordinated renal and muscle adaptations to preserve K+ and Na+ homeostasis during a K+ deficient diet in mice.MethodsMale C57BL/6 mice were fed control (1K) or K+ deficient (0K) diets for 10 days. Urine was collected overnight at 6 days in metabolic cages. Kidney and muscle were collected at 10 days. [Na+] and [K+] were determined by flame photometry in plasma, urine and muscle (mixed gastrocnemius + soleus) extracts. Transporter abundance was assessed by quantitative immunoblot.ResultsPlasma [K+] fell from 4.8 ± 0.3 (1K) to 2.3 ± 0.3 mM (0K) and plasma [Na+] was maintained at 148.6 ±1.5 mM (0K). K+ deficient diet reduced muscle [K+] from 125 ± 2 (1K) to 92 ± 5 mM (0K) and doubled muscle [Na+] from 30 ± 1 (1K) to 61 ± 1 mM (0K), expressed as tissue wet weight. 0K diet also reduced muscle Na, K‐ATPase α2 and β2 subunit abundance by 35 and 60%, respectively, consistent with the measured K+ loss and Na+ gain. Urinary K+ excretion fell from 0.19 ± 0.1 (1K) to 0.003 ± 0.001 mmol (0K) while urinary Na+ was not significantly altered by 0K indicative of adaptations to conserve K+ and maintain Na+. Renal sodium transporters changed as follows during K+ deficient diet: proximal tubule Na/H exchanger (NHE3) decreased 35% while NHE3pS552 increased 1.5 fold consistent with lower NHE3 activity; distal tubule Na‐Cl co‐transporter (NCC) phosphorylated at T53 and S71 both increased >1.5 fold, consistent with higher distal tubule Na+ reabsorption; epithelial Na+ channel gamma subunit (ENaCγ) increased >1.5 fold (no cleavage), consistent with accumulation of inactive ENaC.SummaryDuring restricted potassium intake in mice, muscle donates K+ to ECF facilitated by reducing Na, K‐ATPase abundance, and NCC covalent modification coupled with reduced ENaC activity reduces the driving force for K+ secretion. These responses help blunt the fall in plasma [K+], a key determinant of membrane potential. Reduced proximal Na+ reabsorption via NHE3 may drive a tubuloglomerular feedback mediated reduction in GFR to reduce urinary K+ losses. Despite the increase in muscle [Na+] and decrease in proximal Na+ transport there was no evidence for significant changes in sodium excretion.Support or Funding InformationDK083785This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Reduction of circulating renin‐angiotensin following unilateral nephrectomy signals kidney hypertrophy via increase in renal blood flow
Authors: Shimada Satoshi , Cowley Allen W. 
Published: June 2021

RationaleThe compensatory hypertrophy of a remaining kidney after nephrectomy has long been recognized and the molecular and functional responses to these events have been well characterized. However, the signal that triggers these events is unknown. Recent studies have found that nephrectomy of the right kidney in rats results in a rapid increase of renal blood flow of the remaining kidney within the first 30 minutes and activation of the mTOR pathway with consequent hypertrophy. In the present study, we hypothesized that a reduction of circulating renin would immediately occur with removal of the right kidney which could produce an immediate peripheral vasodilation and increase of renal blood flow within the remaining left kidney.MethodsSprague Dawley rats (male; 7 wk age) were anesthetized, the left kidney was denervated and then the right kidney was removed while monitoring immediate changes of systemic mean arterial blood pressure (MAP), left renal arterial blood flow (RBF), and left urine volume (V). Three groups were studied: 1) No drug treatment (n=5); 2) Pretreated with the AT1 receptor blocker Losartan (n=4); 3) Pretreated with Losartan and Angiotensin II administered to return aortic pressure and RBF to normal before removing the right kidney (n=2).ResultsLeft RBF gradually increased from 3.8 to 4.7 ml/min and became stable 30 minutes following removal of the right kidney. A slight decrease of MAP occurred during that time (~4 mmHg) and urine volume nearly doubled from 2.7 to 5.3 μl/min. Rats treated with Losartan exhibited a reduced baseline level of MAP and increased level of RBF but the changes in MAP and RBF following right nephrectomy were abolished. Rats treated with Losartan with Angiotensin II infused to normalize baseline levels of RBF and MAP, also exhibited no increases of RBF following removal of the right kidney.ConclusionWe conclude that rapid reductions of circulating renin‐angiotensin following right kidney nephrectomy produce increased RBF in the remaining kidney which in turn may trigger the compensatory hypertrophy.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Primacy of Chymase over Angiotensin Converting Enzyme in the Production of Angiotensin II in Rat Bone Marrow Tissue
Authors: Yamashita Tomohisa , Ahmad Sarfaraz , Wright Kendra N , VonCannon Jessica L , Varagic Jasmina , Sun Xuming , Wang Hao , Groban Leanne , Ferrario Carlos M 
Published: June 2021

BackgroundThe bone marrow is attracting attention as not only the nidus of circulating blood cells but the source of stem and progenitor cell‐based therapy. Renin‐angiotensin system (RAS) and angiotensin II (Ang II) receptor type 1 in bone marrow participate in hematopoiesis, a target in the evolution of inflammatory processes involved in cardiovascular disease pathogenesis. Extending the original demonstration of RAS components in the rat bone marrow (Strawn et al. Br J Haematol. 2004;126:120–6), this study investigated the existence of an Ang II‐forming pathway in which chymase rather than angiotensin‐converting enzyme (ACE) cleaves the peptide from the newly described substrate angiotensin‐(1‐12) [Ang‐(1‐12)] which functions as an endogenous tissue substrate for the direct formation of Ang II by chymase.MethodsBone marrow tissue was obtained from the tibia of twelve weeks‐old Sprague Dawley rats following systemic perfusion with phosphate buffered saline with or without the secondary addition of Zamboni's fixative. Bone marrow tissues, homogenized with 0.05 M Tris‐HCl and centrifuged at 28,000 g, were subjected to immunoblot and chymase enzymatic activity using high‐performance liquid chromatography (HPLC). Additional samples were prepared for quantitative RT‐PCR analysis normalized to GAPDH. All data were analyzed using GraphPad PRISM 7.0 with P<0.05 considered statistically significant.ResultsFluorescent immunohistochemistry showed the existence of immunoreactive (ir‐) Ang‐(1‐12) and ir‐chymase‐positive cells in rat's bone marrow. Immunoblots showed chymase protein expression in cell pellets but not in supernatants. Assessment of 125I‐Ang‐(1‐12) or 125I‐Ang I hydrolysis in cell pellets in the presence and absence of specific chymase or ACE inhibitors, revealed that production of Ang II by chymase was two‐thousand fold higher compared to ACE (4,531 ± 137 fmol/mg/min and 2.3 ± 0.3 fmol/mg/min, respectively, P<0.0001, n = 6). ANOVA and post‐hoc Tukey's test showed that gene expression of rat mast cell protease‐5 (rMCP‐5) was at least twice higher than rMCP‐1, rMCP‐2 and rMCP‐4.ConclusionThese studies reveal a major role of Ang‐(1‐12) and chymase as the critical pathway for Ang II‐formation in rat's bone marrow. The pleotropic actions of tissue chymase in the degradation of matricellular proteins, activation of matrix metalloproteinases, transforming growth factor‐β, and production of inflammatory cytokines posits this alternate pathway for Ang II‐production as most relevant in understanding and treating cardiovascular disease.Support or Funding InformationThis study was supported by the National Heart, Blood, Lung Institute of the NIH through HL‐051952 grant.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Exercise enhances placental angiogenesis of obese maternal mice
Authors: Son Jun Seok , Liu Xiangdong , Chen Yanting , Tian Qiyu , Zhao Liang , Hu Yun , Chae Song Ah , Deavilla Jeanene , Zhu Mei‐Jun , Du Min 
Published: June 2021

Placenta is highly vascularized, which is critically for its function in nutrient transportation. Maternal obesity reduces placental vascularization, thus, negatively affecting fetal development and predisposing offspring to adult diseases. Physical activities have been reported to induce angiogenesis in muscle, and we hypothesized that exercise during pregnancy enhances placental vascularization, which prevents negative changes in placental blood vessel density due to maternal obesity.PURPOSETo examine the effects of maternal exercise on placental angiogenesis in high fat diet (HFD)‐induced obese mothers.METHODSFemale C57BL/6J mice were randomly assigned into four groups: control (CON), exercise (EX), HFD, and HFD with exercise (HFDEX). Mice were fed either a control diet containing 10 kcal% from fat, or a high fat diet containing 60 kcal% from fat for 8 weeks before mating. After mating, exercise intervention was performed during gestation every morning for 60 min at moderate intensity including warming up and cooling down. Maternal mice were euthanized, and placenta and fetuses were collected at embryonic day 18.5 (E18.5). Statistical difference was analyzed using student's t‐test and/or one‐way analysis of variance (ANOVA).RESULTSExercise intervention during gestation reduced body weight (P < 0.05) for both CON and HFD maternal mice, but fasting blood glucose level was only reduced (P < 0.001) in HFDEX group. There was no difference in food intake among groups. The average weight of fetuses was heavier (P < 0.001) in HFD than CON and HFDEX, while no difference among CON, CONEX, and HFDEX. The placental weight was higher in both exercise groups compared to no‐exercise groups. The mRNA expression of vasculogenic markers, Vegfa, Vegfr1, Fgf2, Fgfr2, Hif1a, Ccn1, and Gcm1, was reduced in HFD placenta compared to CON, which was recovered due to exercise. In addition, compared with CON, the blood vessel density was lower in HFD group (P < 0.01) but increased (P < 0.01) in HFDEX group.CONCLUSIONSMaternal obesity impaired placental angiogenesis, which was recovered due to exercise, suggesting that exercise during pregnancy is particularly important for obese mothers in order to improve placental vascular development and function, thus offspring health.Support or Funding InformationSupported by NIH Grant R01HD067449.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Kisspeptin signaling in oocytes is compulsory for ovulation in adult mice
Authors: Ruohonen Suvi T , Gaytan Francisco , Gaudi Andrea Usseglio , Franssen Delphine , Ohlsson Claes , Poutanen Matti , Tena‐Sempere Manuel 
Published: June 2021

Kisspeptins, encoded by the Kiss1 gene, are crucial brain factors for the control of reproduction, with an essential role in the generation of the pre‐ovulatory surge of gonadotropins and, hence, ovulation. Yet, kisspeptins are also found in peripheral reproductive organs and their receptor, Gpr54, is expressed in various target tissues, including the ovary, where its physiological role remains contentious. Global Gpr54−/− mice are hypogonadotropic and infertile; female null mice display disrupted folliculogenesis and anovulation. However, despite the predominant brain actions of kisspeptins, how much of this phenotype is due to local, and not central, kisspeptin signaling deficiency remains unknown. To address this, we generated a conditional oocyte‐specific Gpr54 deficient mouse line (OoGpr54−/−), by crossing Gdf9‐Cre+ mice with Gpr54loxP/loxP mice. The efficacy of Gdf9‐promoter to drive the expression of Cre in oocytes was verified by a breeding test, and the Gpr54 depletion from oocytes was confirmed with RT‐qPCR. At the time of pubertal transition, OoGpr54−/− females were indistinguishable from their wiltype controls with preserved puberty onset. However, already at 2 months of age, 45% of OoGpr54−/− females showed histological features reminiscent of ovarian failure, with presence of large atretic antral follicles and absence of corpora lutea as an index of anovulation. These features were also associated with disrupted estrous cyclicity characterized by an increase in the length of the estrus phase of the uterine cycle. Penetrance of this phenotype progressed with age, with 55% of OoGpr54−/− females at 3–4 months, 80% at 6 months and 100% at 10 months displaying features of complete premature ovarian insufficiency (POI). In addition, 4‐month‐old OoGpr54−/− female mice displaying POI showed decreased serum estradiol and progesterone levels, yet sustained Gpr54 expression in the hypothalamus and unaltered basal gonadotropin levels. Ovarian RNASeq analyses revealed global changes in expression profiles in OoGpr54−/− mice, including genes involved in cellular communication, steroidogenesis and intracellular signaling pathways. Finally, the anovulatory state of OoGpr54−/− mice was rescued by exogenously administered gonadotropin priming, and was largely prevented by early onset consecutive pregnancies, although multiparous OoGpr54−/− dams showed a slight decrease in fecundity. Our results pinpoint the important role of oocyte kisspeptin signaling in the direct control of ovulation, whose deregulation may also be an underlying cause for POI in women.Support or Funding InformationFiDiPro programme of Academy of Finland and Sigrid Juselius foundationThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.