bluuebunny/crossref_metadata_2025_split huggingface dataset:
Kinin B1 Receptor Antagonism Attenuates DOCA‐Salt Hypertension by Modulating Angiotensin II Signaling in the Brain
Authors: Sriramula Srinivas 
Published: June 2021

Deoxycorticosterone acetate (DOCA)‐salt hypertension is associated with increased expression of the pro‐inflammatory kinin B1 receptor (B1R) and elevated angiotensin II (Ang II) levels in the brain. We previously reported that DOCA‐salt hypertension is attenuated in global B1R knockout mice. However, the direct association between Ang II signaling and B1R has not yet been fully studied. In this study, we tested the hypothesis that central blockade of the B1R attenuates DOCA‐salt hypertension by altering angiotensin signaling within the brain. DOCA‐salt treatment (1mg/g body wt. DOCA, 1% saline in drinking water for 3 weeks) significantly increased blood pressure (BP; radiotelemetry) in male wild‐type (WT) mice (145 ±3 mmHg, n=8, p<0.01) compared to control mice (106 ±3 mmHg, n=6). Chronic intracerebroventricular (ICV) infusion of R715, a specific B1R antagonist, attenuated the DOCA‐salt‐induced hypertension (122 ±4 mmHg, n=8, p<0.01). Measurement of Ang‐II levels using ELISA revealed a 3‐fold increase in the hypothalamus (n=6, p<0.01 vs. Control) of hypertensive mice, which was blunted by ICV treatment with R715 for 3 weeks. In WT mice, DOCA‐salt treatment resulted in up‐regulation of angiotensin type‐1 receptor (AT1R; 3‐fold, n=6, p<0.01 vs. Control) and concomitant reduction of Mas receptor (30% decrease, n=6, p<0.01 vs. Control) gene expression in the hypothalamic paraventricular nucleus. Conversely, ICV treatment with R715 abrogated these receptor expression changes. To further confirm the pivotal role of neuronal B1R, hypothalamic primary neurons isolated from neonates were exposed to LDABK, a specific B1R agonist (300 nM, 24 h) after 14 days of culture. Treatment with LDABK significantly increased the gene expression of AT1R (2.5‐fold, n=6, p<0.01 vs. Vehicle) and this effect could be blocked by pretreatment with the B1R antagonist, R715 (10 μM, 30 min prior). Together, these data provide novel evidence that kinin B1R antagonism modulates angiotensin signaling in the brain and there by attenuates the development of DOCA‐salt hypertension.Support or Funding InformationThe American Heart Association (15SDG25720021)This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Local ionotropic glutamate receptor activity is required for the ramp‐like increase of sympathetic activity induced by PVN TNFα
Authors: Mourao Aline Andrade , Pedrino Gustavo Rodrigues , Toney Glenn M. 
Published: June 2021

Central nervous system actions of pro‐inflammatory cytokines (PIC) play a pivotal role in driving exaggerated sympathetic nerve activity (SNA), a major aggravating factor in cardiovascular and metabolic diseases. We previously reported that delivery of tumor necrosis factor alpha (TNFα), a prototypical early onset PIC, into the hypothalamic paraventricular nucleus (PVN) elicits a progressive, ramp‐like, increase of splanchnic SNA (SSNA) that resembles the response to sympathoexcitatory stimuli such as plasma insulin and leptin. Here we investigated the contribution of local ionotropic glutamate receptors both in triggering and sustaining this SNA response. In anesthetized (α‐chloralose/urethane) male Sprague‐Dawley rats, unilateral PVN injection of vehicle (aCSF) was without affect, but subsequent injection of TNFα (0.6 pmol/50 nl) elicited a significant (P<0.0001) ramp‐like increase of SSNA that averaged +55 ± 5.5% over a period of 60 min. Mean arterial pressure and heart rate were unaffected. Separate PVN pretreatment with the AMPA receptor antagonist NBQX (5.2 nmol/50 nl) and the NMDA antagonist AP5 (24 nmol/50 nl) (n = 5/group) each significantly attenuated (P<0.05) the TNFα elicited SSNA response (55 ± 5.5 % vs. NBQX: 24 ± 5% vs. AP5: 32 ± 6.5%) at the 60 min post‐TNFα time point. PVN pretreatment with a cocktail of NBQX and AP5 abolished the TNFα‐induced SSNA ramp (55 ± 5.5 % vs. 1.3 ± 2.1%; P<0.0001). When delivered separately into the PVN 60 min after TNFα, neither NBQX nor AP5 significantly altered the rate of SSNA ramping over an additional 60 min period. These results indicate that ionotropic glutamate receptor activity in the PVN is required to initiate the progressive increase of SSNA triggered by TNFα, and hint that sympathoexcitatory stimuli such as TNFα that elicit a PVN‐driven ramp‐like SNA response might do so by inducing a long‐term potentiation (LTP)‐like form of glutamatergic synaptic plasticity.Support or Funding InformationCapes (AAM, GRP), NIH HL088052 & AHA 25710176 (GMT)This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Neuropeptide Y Receptor Y1 (NPY Y1) Inhibition Attenuates Intestinal Inflammation in Murine Colitis and Human IBD Biopsy Cultures
Authors: Chandrasekharan Bindu , Saeedi Bejan , Dhere Tanvi , Neish Andrew S 
Published: June 2021

RationaleInflammatory bowel disease, characterized by intestinal inflammation, is commonly treated with drugs targeted against the pro‐inflammatory cytokine tumor necrosis factor (TNF). However anti‐TNF drugs are expensive, and some patients stop responding to anti‐TNF's over time.AimBased on our published findings that neuropeptide Y (NPY) can regulate TNF levels in the gut, we investigated the efficacy of neuropeptide Y (NPY) inhibition in attenuating intestinal inflammation by selectively blocking NPY receptor Y1 (NPY Y1) in mouse model of dextran sodium sulfate(DSS)‐induced colitis, and in colonic biopsies from patients with inflammatory bowel disease (IBD) ex vivo.MethodsColitis was induced in mice (129S strain) by administration of 3% DSS in drinking water for 7 days. NPY Y1 inhibition was achieved via intra rectal administration of NPYY1 antagonist BIBP‐3222 (@ 10 mg/kg of mouse body weight) on alternate days during the DSS treatment. Mice were monitored for weight loss, fecal blood and diarrhea (clinical score), colon length, histological score, TNF expression (by real time PCR and enzyme linked immunosorbent assay/ELISA) and on day 7 subjected to endoscopy. Colonic biopsies were obtained from healthy volunteers (n = 10) and IBD patients (n = 8), and biopsies were cultured ex vivo in presence or absence of BIBP‐3222 (0.1mM) for 24 h (at 37°C, 5% CO2).ResultsIn mouse models of (DSS)‐induced colitis, NPY Y1 inhibition resulted in significant protective effects as determined from the clinical score and histological scores, colon length and endoscopic colitis score (p < 0.05). TNF mRNA was also significantly downregulated in the colon of DSS + BIBP‐treated mice as compared to DSS ‐ treated mice (p < 0.05). Colonic biopsies from IBD patient's ex vivo depicted significant increase in TNF levels as compared to biopsies from healthy subjects (p < 0.05). Incubation of IBD patient biopsies with BIBP‐3222 was effective in significantly inhibiting TNF release by at least 50 % as determined by ELISA (p < 0.05).ConclusionsTaken together, our data suggests that NPYY1 inhibition is effective in attenuating intestinal inflammation in murine colitis and human IBD biopsies ex vivo.Support or Funding InformationWe acknowledge the support from Litwin‐IBD Pioneers Initiative grant from Crohn's & Colitis Foundation (B.C) and the U.S. National Institutes of Health grants AI64462 & DK089763 (A.S.N.)This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
The Role of Sensory Nerves in Modulating Antigen Specific Immune Responses
Authors: Tynan Aisling , Gunasekaran Manojkumar , Tsaava Téa , Imperato Gavin H , Chavan Sangeeta S , Tracey Kevin J 
Published: June 2021

The nervous and immune systems are the two major organ systems of memory and host defense. Both systems sense changes in the environment, mobilize host responses, and establish memories of threatening insults. Immunological memory is developed by T and B cells, which retain antigen‐specific information for decades. Upon subsequent challenge with the same antigen, antigen‐specific B cells proliferate resulting in a rapid and robust secondary antibody response that neutralize and eradicate the antigen. However, little is known about the role of sensory neurons in modulating antigen‐specific B cells responses. We have previously demonstrated that local sensory neural network plays a vital role in regulating antigen trafficking through the lymphatic system in vivo. Here, we show that TRPV1‐expressing sensory neurons are involved in the regulation of immune responses. Specific genetic ablation of TRPV1‐lineage neurons results in a failure to generate a robust antigen‐specific antibody response following immunization (Anti‐KLH IgG levels Day 28, Wild type 8243.64 U/ml versus TRPV1 ablated 1068.60 U/ml). However, in vitro stimulated B‐cells from TRPV1‐ablated mice produce similar levels of IgG as wild type littermate controls suggesting that there is not a B‐cell intrinsic defect in TRPV1‐ablated mice. Co‐culture of splenocytes with sensory neurons results in an increased level of antibody production. Direct activation of TRPV1+ signals by selective optogenetic stimulation (5 minutes, 473nm laser, 10Hz, 50% duty cycle) results in a significat decrease of antigen trafficking to the popliteal lymph node as compared to sham controls (Sham 11012691 Average Fluorescent Volume versus Photostimulated 5330646 Average Fluorescent Volume, p<0.05). These findings, together with our previous studies, implicate a neuro‐immune crosstalk in both physiological and pathological conditions, and raises the exciting possibility that the nervous system collaborates with the immune system to regulate antigen‐mediated responses.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Muscle Sympathetic Activity Kinetics during One‐leg Cycling in Men and Women with and without Heart Failure: Evidence for Preserved Cardiopulmonary Baroreflex Sympathoinhibition
Authors: Millar Philip J , Notarius Catherine F , Picton Peter , Haruki Nobuhiko , Floras John S 
Published: June 2021

Microneurographic recordings of muscle sympathetic nerve activity (MSNA) are generally analyzed over discrete epochs, usually in minutes. This is sufficient for determining resting sympathetic outflow but may obscure physiologically relevant information regarding temporal changes during an acute stress, such as exercise. To address this limitation, we applied a moving average to examine continuously the effects of one‐leg cycling on MSNA in 22 participants with (n=11) and without (n=11) heart failure with reduced ejection fraction (HFrEF). MSNA burst frequency and incidence were acquired over an 8 minute period: 2 minutes of baseline, zeroload cycling, moderate intensity cycling (50% of VO2 peak), and recovery. MSNA was analyzed in 30 second epochs, advancing in five‐second increments to create a 91 point overlapping moving average plot. Area under the curve analysis demonstrated that both MSNA burst frequency and incidence were higher in HFrEF than controls during zeroload and moderate intensity cycling (both, p<0.05). To estimate the reflex sympathoinhibitory consequences of skeletal muscle‐pump induced increases in cardiopulmonary blood volume at the start of exercise, we calculated the nadir reduction in MSNA burst frequency and incidence during the first 30 seconds of zeroload (HFrEF vs. controls: −6±7 vs. −7±4 bursts/min; −12±11 vs. −15±5 bursts/100 heartbeats) and moderate intensity (HFrEF vs. controls: −7±5 vs. −6±7 bursts/min; −11±7 vs. −8±9 bursts/100 heartbeats) cycling; no differences were observed between HFrEF and controls (all, p>0.05). Such initial reductions in MSNA burst frequency were observed in 9/11 HFrEF and 11/11 controls with zeroload cycling; reductions occurred in 11/11 HFrEF and 7/11 controls with moderate intensity cycling (both, p>0.05). These similar group‐mean magnitude reductions in MSNA at the onset of exercise are consistent with preserved cardiopulmonary‐reflex mediated sympathoinhibition in HFrEF; the subsequent increase in MSNA is consistent with an exaggerated muscle metaboreflex contribution. As peripheral neurogenic vasoconstriction contributes to exercise intolerance in HFrEF, exercise regimens with shorter durations (e.g. high intensity interval training) may be better tolerated and more efficacious elements of conditioning protocols for such patients.Support or Funding InformationThis study was supported by Grants‐in‐Aid from the Heart and Stroke Foundation of Ontario (T4938, NA6298). P.J.M. was supported by a Canadian Institutes of Health Research Postdoctoral Fellowship. J.S.F. was supported by the Canada Research Chair Program.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Vasopressin V1a Receptor of Renal Collecting Duct Intercalated Cells Promotes Urinary Proton Secretion
Authors: Giesecke Torsten , Koshimizu Taka‐Aki , Kawahara Katsumasa , Gimber Niclas , Schmoranzer Jan , Himmerkus Nina , Isermann Julian , Bleich Markus , Assay Niklas , Leipziger Jens , Fähling Michael , Smorodchenko Alina , Bachmann Sebastian , Mutig Kerim 
Published: June 2021

Antagonists of the V1a vasopressin receptor (V1aR) are emerging as a therapeutic strategy for retardation of chronic kidney disorders. Physiologically, V1aR signaling has been linked with acid‐base homeostasis, although the underlying mechanisms remain debatable. In this study, we tested the hypothesis that V1aR activation in type A intercalated cells (A‐ICs) induces urinary H+ secretion.We generated an anti‐V1aR antibody and verified its specificity using V1aR‐knockout tissues. Localization studies in mice, rat and human tissue, were preformed using immunofluorescence and confocal microscopy or 3D‐structured illumination microscopy (3D‐SIM). For functional studies in vivo, V1aR‐specific agonist, AO‐4‐67, was administered in AVP‐deficient Brattleboro rats and C57/BI6J mice (0.2, 2, or 10μg/kg b.w.; 1 to 4h). Urine was collected in metabolic cages or via ureteral catheter and plasma samples were taken. Isolated, microperfused mouse collecting ducts were analyzed for V1aR‐dependent luminal pH changes and cultured inner medullary collecting duct cells for proton‐secreting vH+‐ATPase regulation.Localization of V1aR in mouse, rat and human kidneys produced basolateral signal in A‐ICs and perinuclear to subapical signal in type B intercalated cells of connecting tubules and collecting ducts throughout these species. In addition, basolateral V1aR signal was detected in macula densa cells of mouse but not rat or human kidneys. Administration of the V1aR agonist, A0‐4‐67, significantly decreased urinary pH in vasopressin‐deficient Brattleboro rats (10 μg/kg body weight for 4 hours i.p.; pH 7.38 to 6.71 after 1 hour, P<0.01) and C57/BI6J mice (2 μg/kg body weight for 1 hour i.p.; pH 7.18 to 6.78 after 20 minutes, P<0.05). Basolateral treatment of isolated perfused medullary collecting ducts with the V1aR agonist or vasopressin increased intracellular Ca2+ levels in intercalated cells and decreased luminal pH (pH −5% after 3 minutes, P<0.05) suggesting V1aR‐dependent Ca2+ release and stimulation of proton secreting proteins. Basolateral treatment of inner medullary collecting duct cells with the V1aR agonist induced luminal translocation of vacuolar H+‐ATPase in A‐ICs (apical signal intensity +93%, P<0.001).In summary, our results show that activation of V1aR contributes to urinary acidification via H+ secretion by A‐ICs, which may have clinical implications for pharmacological targeting of V1aR.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
miR‐137 mediates TNF‐dependent inhibition of Aquaporin 2 expression
Authors: Hao Shoujin , DelliPizzi AnnMarie , Hao Mary , Ferreri Nicholas R. 
Published: June 2021

We previously showed that TNF produced by renal epithelial cells inhibits NKCC2 activity as part of a mechanism that attenuates increases in blood pressure in response to increases in sodium intake. We also showed that ambient urine osmolality was higher in TNF deficient mice compared with age‐ and sex‐matched wild type (WT) mice. As the role of TNF in the kidney is still being defined, the effect of TNF produced by renal epithelial cells on aquaporin‐2 (AQP2) expression was determined in this study. TNF levels were higher in urine, but not plasma, of mice that ingested 1% NaCl (HS) in the drinking water for three days compared with tap water (40±4 vs 18±5 pg/24 h). The increase in urinary TNF levels was associated with an approximately 5‐fold increase in TNF mRNA abundance in the inner medulla excised from mice given HS. Interestingly, we observed that miR‐137 levels also increased approximately 2‐fold in the inner medulla isolated from mice given HS. Six days after intrarenal injection of a lentivirus construct designed to silence TNF, EGFP‐shTNF‐ex4, renal but not splenic TNF mRNA levels were significantly reduced. Injection of control lentivirus (U6) did not alter TNF mRNA in either kidney or spleen. RT‐PCR analysis showed that AQP2 mRNA levels were significantly decreased in the inner medullary tissue from mice given HS. However, renal silencing of TNF in mice given HS exhibited a 3‐fold increase in AQP2 mRNA and protein expression in the inner medulla compared with WT. In contrast, EGFP‐shTNF‐ex4 but not U6 decreased miR‐137 levels in the inner medulla in mice given HS. Moreover, target seed regions of miR‐137 were conserved in the 3′‐untranslated region of mouse AQP2 mRNA. Accordingly, intrarenal injection of miR‐137 inhibited the increase of AQP2 mRNA abundance in the inner medulla induced by silencing TNF in the kidneys of mice given HS. As TNF production in the kidney was induced by administration of HS for 3 days, the effects of TNF silencing on urine volume were determined. Mice were acclimated in metabolic cages for 3 days after receiving intrarenal injections of either EGFP‐shTNF‐ex4 or U6. Food, body weight, water intake, and urine output was then measured in mice given HS or tap water for 3 days. Both water intake and urine output were reduced in mice injected with EGFP‐shTNF‐ex4 compared with mice given U6 lentivirus. The decrease in urine volume was associated with an increase in AQP2 mRNA accumulation. Collectively, these findings suggest that the intrinsic effects of TNF produced within the kidney in response to HS intake include an inhibitory effect on AQP2 expression that is mediated via a mechanism involving miR‐137.Support or Funding InformationNIH(HL133077)This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Aldosterone‐Induced MicroRNAs Act as Negative Feedback Regulators for the Mineralocorticoid Receptor in Kidney Distal Nephron Epithelia
Authors: Ozbaki‐Yagan Nejla , Liu Xiaoning , Bodnar Andrew J , Ho Jaqueline , Butterworth Michael Bruce 
Published: June 2021

Regulated sodium (Na+) homeostasis in the kidney is achieved by the action of the renin‐angiotensin‐aldosterone signaling cascade. The terminal signaling hormone, aldosterone binds to the mineralocorticoid receptor (MR) to increase Na+ uptake across tubule epithelial cells by altering the expression and function of channels, transporters and regulatory proteins acting in concert. Along with a change in gene and protein expression, aldosterone regulates the expression of non‐coding RNAs including microRNAs (miRs). The primary function of miRs is to repress target mRNA expression and decrease protein abundance. Extended aldosterone stimulation (1–7 days) is known to reduce MR expression (protein and mRNA) in cell and animal models. To investigate if miRs were involved in this negative feedback regulation of the MR, we profiled the expression of miRs predicted to bind to the MR‐3’untranslated region (UTR) in mouse cortical collecting duct (mCCD) epithelial cells stimulated with aldosterone (50nM). Of the significantly altered miRs, the miR‐466a‐e family members were most highly upregulated (>5 fold). This upregulation was verified in vivo in CCD cells isolated from mouse kidneys of animals placed on low Na+ diets for 3 days. Luciferase assays confirmed miR‐466 binding to the MR‐UTR. Preventing the upregulation of miR‐466 after aldosterone stimulation, using miR inhibitors increased MR protein expression. Aldosterone‐stimulated sodium transport via the epithelial sodium channel in miR‐466 inhibited CCD cells was significantly higher than control transfected cells. The Na+‐stimulation was sustained over extended periods (24–72hrs) and miR‐466 inhibited cells had increased aldosterone sensitivity. In conclusion, we have identified a role for the miR‐466's in the negative feedback regulation of MR after extended aldosterone stimulation. Inhibition of miR‐466 released this feedback regulation to allow for a larger, more sensitive and more sustained response to aldosterone stimulation.Support or Funding InformationNIDDK R01DK103776 (JH) NIDDK DK102843 (MB)This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
G‐protein Pathway Suppressor 2 (GPS2) Enhanced the Big Potassium (BK) Channels Activity through modulating interaction between GPS2 and WNK4
Authors: Wang Yunman , Luo Tongwang , Li Ruidian , Cai Hui 
Published: June 2021

The Large Conductance Ca2+ Activated Potassium (BK) Channels plays an important role in renal potassium secretion. G‐protein pathway suppressor 2 (GPS2) is a multifunctional protein and transcriptional regulation factor that is involved in the G‐protein mitogen‐activated protein kinase (MAPK) signaling pathway. We have previously reported that WNK4 inhibits BK channel activity by stimulating ERK1/2 and p38 signaling pathways. We have recently shown that GPS2 enhances BK channel activity and its protein expression by reducing ERK1/2 signaling‐mediated degradation of the channel. We therefore hypothesized that GPS2 stimulates BK channel activity through its interaction with WNK4. We first investigated whether GPS2 interacts with WNK4. In HEK293 cells cotransfected with HA‐WNK4 and either myc‐vector or myc‐GPS2, co‐immunoprecipitation (co‐IP) experiments showed that myc‐GPS2 is able to co‐immunoprecipitate WNK4, whereas myc‐vector does not. To confirm their interaction, we performed the reciprocal co‐IP experiments in HEK293 cells co‐transfected with HA‐GPS2 and either myc‐vector or myc‐WNK4. We found that myc‐WNK4 co‐precipitates HA‐GPS2 while myc‐vector does not. To further assess the effects of GPS2 on WNK4‐mediated inhibitory effects on BK, we performed the western blot analysis in HEK293 cells cotransfected with BK with or without WNK4 in the presence or absence of GPS2. We found that WNK4 significantly inhibits BK protein expression as expected. However, in the presence of GPS2, BK protein expression is restored to the control level. To explore whether GPS2 affects WNK4 protein degradation we did WNK4 ubiquitination experiment. In Cos‐7 cells co‐transfected with WNK4 with or without GPS2, we showed that GSP2 significantly enhances WNK4 ubiquitination, suggesting that GPS2 promotes WNK4 degradation. We further showed that GPS2 reversed the WNK4‐mediated inhibition of BK protein expression by partially reducing the BK degradation through both proteosomal and lysosomal pathways. These data suggested that GPS2 stimulates BK activity through its interaction with WNK4, leading to enhancing WNK4 ubiquitination and degradation via both proteosomal and lysosomal pathways.Support or Funding InformationVA Merit AwardThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.