bluuebunny/crossref_metadata_2025_split huggingface dataset:
Metabolic stress directs WNK kinases to aggresomes for pooling and degradation in the distal convoluted tubule of the kidney
Authors: Thomson Martin Nikolaus , Gallardo Catherina Cuevas , Bewarder Tim Michael , Ellison David , Mutig Kerim , Bachmann Sebastian 
Published: June 2021

ObjectiveRenal salt retention due to excessive function of the renal NaCl cotransporter (NCC) along the distal convoluted tubule (DCT) plays a central role in the pathogenesis of hypertension. The Western type diet with high salt and low potassium content (HS/LK) has been shown to increase NCC activity by stimulating its phosphorylation via a kinase cascade comprising with‐no‐lysine kinases (WNKs) and a Ste20‐related kinase (SPAK). WNKs and SPAK have been shown to accumulate in perinuclear aggregates in response to potassium depletion, but the functional significance of these aggregates remained obscure. These structures may in part reflect a degradative pathway but may serve pooling functions as well.MethodsMice received HS/LK or control diets for 10 days. WNK1‐transfected DCT cells were exposed to vehicle, hyperosmotic stress, or potassium depletion. WNK1, WNK4, SPAK, phospho‐S383 SPAK, and various autophagy markers were studied by immunofluorescence and immunoblotting. Electron microscopy was applied for ultrastructural analysis.ResultsHS/LK diet induced accumulation of WNKs and SPAK in the form of perinuclear protein aggregates within DCT cells. These aggregates were rare in DCT of mice treated with control diet and virtually absent after administration of high potassium diet. The autophagy marker ATG5 was present in the aggregates and the 20S proteasome signal was intensified adjacently, whereas standard lysosomal markers showed no significant association with the punctate WNK/SPAK signal. Ultrastructural analysis of DCT in kidneys of mice treated with HS/LK revealed abundant aggresomes adjacent to rough endoplasmic reticulum and clathrin‐coated vesicles. Evaluation of cultured DCT cells transfected with WNK1 or KS‐WNK1 revealed formation of similar aggresomes in response to potassium depletion, whereas hyperosmotic stress induced formation of autophagosomes. Pretreatment of cells with proteasome inhibitor MG‐132 or autophagy/lysosome inhibitor bafilomycin A1 prior to potassium depletion substantially augmented the size of WNK1‐containing aggresomes.ConclusionChallenging of DCT epithelium induces the formation of perinuclear aggresomes which pool the components of the kinase cascade controlling NCC activity. From there, WNKs and SPAK may either be degraded via proteasomes or lysosomes, or reintroduced into the signal chain.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Methylenedioxypryovalerone (MDPV) Rapidly Increases Dopamine Transporter and Vesicular Monoamine Transporter‐2 Function
Authors: German Christopher L. , Magee Charlotte P. , Curtis Peter S. , Hanson Glen R. , Fleckenstein Annette E. 
Published: June 2021

Methylenedioxypyrovalerone (MDPV) is a synthetic cathinone designer drug primarily abused for its psychostimulant properties. Rapid dysregulation of central monoamine neurotransmitter transport into presynaptic terminals and synaptic vesicles are principal mechanisms of psychostimulant action, and contribute to the development of persistent monoaminergic deficits. Still, the impact of in vivo MDPV administration on the function of central monoamine transporters is not fully elucidated. Consequently, this study examined the response of the striatal dopamine transporter (DAT) and vesicular monoamine transporter‐2 (VMAT2) to a single MDPV exposure in adult male rats. A single in vivo MDPV administration rapidly (within 1 h) and reversibly (effect diminishes after 6 h) increased both DAT and VMAT2 function when assessed ex vivo in striatal synaptosomes and non‐membrane‐associated (presumably cytoplasmic) synaptic vesicles, respectively. MDPV treatment did not increase VMAT2 immunoreactivity within the cytoplasmic synaptic vesicle fraction, suggesting increased VMAT2 activity is unlikely due to intracellular trafficking increasing the number of available cytoplasmic VMAT2‐associated synaptic vesicles. In contrast to other psychostimulants, most notably methamphetamine and methylphenidate, MDPV acutely increases both DAT and VMAT2 function, and increased VMAT2 function is likely independent of vesicular trafficking‐mediated mechanisms. Together, these data suggest that MDPV has a unique and undescribed mechanism of action on striatal dopaminergic neurons.Support or Funding InformationThis work was supported by National Institutes of Health grants DA039145 and DA031883.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
The effects of lipid lowering drugs on neuroinflammation in metabolic syndrome mice
Authors: Hsieh Liang‐Po , Yeh Ching Hua 
Published: June 2021

People get used to high‐calorie and refined dishes diet and lack of physical exercises with rapid modern lifestyles change. Those bad habits contribute to the increasing prevalence of metabolic syndrome. The peripheral chronic inflammatory responses are related to the adipose tissue accumulation and hyperlipidemia in the metabolic syndrome patients. Depression is an important comorbidity with metabolic syndrome. The inflammatory cytokines secreted by activated inflammatory cells in peripheral tissue would induce central neural inflammation. Chronic brain inflammation may be linked to depression. We hypothesize that depression occurrence in metabolic syndrome patients is due to the peripheral and central neural inflammation. We evaluated whether fenofibrate or Statin could improve depression‐like behavior in metabolic syndrome mice. The metabolic syndrome mice were induced by high‐fat‐diet. The depression‐like behaviors in metabolic syndrome mice were analyzed by tail suspension test, open field test and sucrose preference test. After 4‐week treatment of fenofibrtae and Statin, the depression‐like behavior in mice were analyzed and then sacrificed. The expressions of inflammatory cytokines in the brain of mice were detected by RT‐PCR. The activation of macrophage and microglia were analyzed using IHC stain. The results showed that body weight, TG, TC in serum and adipose tissue weight of mice were increased after high‐fat‐diet fed. That confirmed metabolic syndrome was induced successfully in the mice. In behavior analysis, fenofibrate decreased immobility times of tail suspension, increased number of line crossing of open field test, and increase sucrose intake of sucrose preference test indicating that PPARα activation may improve depression‐like behavior. The data showed that fenofibrate could improve depression level in metabolic syndrome mice.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Pharmacological Cathepsin C Inactivation Eliminates Proteinase 3, the Antigen in Autoimmune Vasculitis
Authors: seren seda , Dallet‐Choisy Sandrine , Marchand‐Adam Sylvain , Korkmaz Brice 
Published: June 2021

Membrane‐bound proteinase 3 (PR3) is the main target antigen of anti‐neutrophil cytoplasmic autoantibodies (ANCA) in granulomatosis with polyangiitis (GPA), a systemic small‐vessel vasculitis. Binding of ANCA to membrane PR3 triggers neutrophil activation with the secretion of enzymatically active PR3 and additional granule proteins, thereby contributing to vascular damage. PR3 and related neutrophil serine proteases (NSP) are activated from proforms by the lysosomal cysteine protease cathepsin C (CatC) during neutrophil maturation. We hypothesized that pharmacological inhibition of CatC provides an effective measure to reduce intracellular and membrane‐bound PR3 and has therefore implications as a novel therapeutic approach in GPA. We first studied PR3 in neutrophils from 21 patients with Papillon‐Lefèvre syndrome (PLS), a genetic form of CatC deficiency. PLS neutrophil lysates showed a largely reduced, but still detectable (0.5–4%) PR3 activity when compared to healthy control cells. The PR3 membrane expression on activated PLS neutrophils was diminished by approximately 80% as shown by flow cytometry. We then explored the effect of a potent cell permeable nitrile CatC inhibitor on PR3 expression in normal neutrophils using a CD34+ hematopoietic stem cell model. Human CD34+ hematopoietic stem cells were treated with a CatC inhibitor during neutrophil differentiation over 10 days. We observed complete abrogation of membrane PR3, cellular PR3 protein and proteolytic PR3 activity whereas neutrophil differentiation was not compromised. Our data suggest that pharmacological CatC inhibition could provide an attractive novel treatment strategy for PR3‐ANCA associated autoimmune vasculitis that should be explored further.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
The Role of Cytoplasmic Deacetylase, SIRT2, in Stabilizing Lung Endothelial Barrier Function
Authors: Yang Xiaoyan , Yang Deying , Chen Zhang , Komarova Yulia 
Published: June 2021

Lung microvascular endothelial functional and structural integrity is essential for maintenance of tissue‐fluid homeostasis and normal function of the respiratory system. Disruption of the pulmonary endothelial barrier leads to pulmonary edema, acute lung injury, and respiratory failure. Adherens junction (AJ) proteins, actin cytoskeleton, and microtubules are major components required for maintenance of barrier integrity. Post‐translational protein modifications of AJ constituents, such as phosphorylation, nitration, and nitrosylation, have been well known to regulate endothelial barrier function. More recently, lysine acetylation/deacetylation has emerged as an important and physiologically significant posttranslational protein modification in physiological and pathological conditions. However, its role in endothelial barrier function remains largely unknown. Sirtuins (SIRTs) are NAD+‐dependent deacetylases, and critical regulators of energy metabolism and oxidative stress response in different cell types. We studied the function of SIRT2, the only cytosolic sirtuin family member, in regulating pulmonary endothelial barrier function during inflammatory response. We showed that SIRT2 is the most abundant sirtuin in human lung endothelial cells. Importantly, SIRT2 protein level is significantly increased in lung endothelial cells upon challenging mice with a sublethal dose of lipopolysaccharides, a gram‐negative bacteria endotoxin which causes systemic inflammatory responses resulting in acute lung injury. Increase in SIRT2 protein level was also observed in human lung microvascular endothelial cells (HLMVEC) upon challenge with permeability‐increasing agents such as human α‐thrombin and TNF‐α, further emphasizing the potentially important role of SIRT2 in regulating adaptation of endothelial cells to inflammatory responses. To determine the role of SIRT2 activity in the maintenance of lung endothelial barrier function, we knocked down SIRT2 in HLMVECs and assessed changes in endothelial permeability upon challenge with α‐thrombin. We found that SIRT2 knock down significantly augmented α‐thrombin‐induced permeability increases as compared to control siRNA‐treated cells, suggesting that SIRT2 activity may play a critical role in regulating endothelial barrier integrity. Furthermore, treatment of endothelial cells with AGK2, a SIRT2‐selective inhibitor, significantly decreased assembly of endothelial junctions due to increased accumulation of VE‐cadherin in the cytoplasm. Our data suggest that SIRT2 plays a critical role in the maintenance of endothelial barrier function under basal conditions and upon inflammatory response.Support or Funding InformationXiaoyan Yang : T32HL007829‐23, AHA 17SDG33410608.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
The Effect of Beetroot on Vascular Contractile Response in Ovariectomized Rats
Authors: Deng Arlinda , Nguyen Huy , Longo Amanda B. , Ward Wendy , MacPherson Rebecca EK. , Di Wang Hui 
Published: June 2021

Hypertension in women is known to peak dramatically following menopause, potentially attributable to the decreasing levels of sex hormones such as estrogen. Estrogen has regulating effects on nitric oxide (NO) bioavailability, a molecule which plays an important role in regulating blood pressure by dilating arteries. However, in post‐menopausal women estrogen therapy causes many adverse events, and an alternate treatment option is required. Beetroot (BR) is a plant that contains dietary nitrates that can increase blood NO levels. In this study, we tested the hypothesis that ingestion of BR will alter vascular tone and control blood pressure in an ovariectomized rodent model.Twelve‐week old female ovariectomized (OVX) Sprague‐Dawley rats were divided to receive BR juice (containing 18.75 mg nitrates), nitroglycerin (NG) (0.2 mg/kg), estradiol replacement (1.5 mg) or no treatment for 12 weeks (n=4 per group). Isolated aortic rings were mounted in tissue baths and isometric contractile force was measured. Cumulative concentration‐response curves to phenylephrine (PE) (10−8 M to 10−5 M) and potassium chloride (KCL 120 mM) were generated to examine contractile function. Superoxide was measured by using chemiluminescence.The aorta rings in the no treatment group developed highest contraction force in response to PE compared to aortic rings from the NG or estradiol‐treated groups (P<0.01). The BR‐treated group had a significantly reduced contractile force compared to no treatment, which was closer to NG and estradiol group levels (P<0.05). BR treatment did not reduce vascular contractions in response to KCL (P>0.05) but significantly reduced superoxide production (P<0.05).These experiments suggest that dietary beetroot would be able to reduce oxidative stress and vascular contraction in response to PE, possibly through the production of nitric oxide.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Extracellular ATP promotes protein synthesis in skeletal muscle through activation of the Akt‐mTOR signaling pathway
Authors: Jiménez Camilo Morales , Calderón Manuel Arias , Hernández Nadia , Jaimovich Enrique , Radic Sonja Buvinic 
Published: June 2021

ObjectiveExtracellular nucleotides are released from different cells surrounding skeletal muscle, like motoneuron, endothelial cells, fibroblasts and bone cells during exercise. Even the muscle fibers themselves release ATP during membrane depolarization and contraction. Could this ATP‐enriched environment modulate protein synthesys in skeletal muscle? In this study, we assessed if extracellular ATP leads to protein synthesis in adult muscle through activation of Akt‐mTOR signaling pathway.MethodsFlexor Digitorium Brevis (FDB) muscles from 6–7 weeks‐old BalbC mice were dissected. Isolated muscles were stimulated with exogenous ATP in a time‐ and concentration‐dependent manner (3–20 min, 0.1 – 100 μM). The relative protein levels of p‐Akt(Ser473), p‐mTOR( Ser2448), p‐p70S6K(Thr389) and p‐4E‐BP1(Thr37/46) were evaluated by immunoblot. Normalization with the non‐phosphorylated protein and GAPDH was performed. The protein synthesis was estimated by the nonradioactive SUrface SEnsing of Translation (SUnSET) technique.Results100 μM ATP increased p‐Akt(Ser473) levels by 3‐fold in 10–15 min. Akt phosphorylation was concentration‐dependent, with a bell‐shaped curve that peaked in 3 μM ATP. Phosphorylation of Akt signalling‐related proteins (mTOR, p70S6K, and 4E‐BP1) and protein synthesis levels were also increased after 10–20 min with 3 μM ATP and UTP. Preincubation for 30 min with a general P2Y/P2X receptors antagonist (100 μM suramin), PI3‐kinase inhibitor (50 μM LY294002) or mTOR inhibitor (100 nM Rapamycin) abolished the effect of ATP on the protein synthesis.ConclusionThese findings suggest that extracellular ATP promotes protein synthesis in skeletal muscle through the activation of P2YRs and the Akt‐mTOR signaling pathway. Considering that effect on protein synthesis was mimicked by UTP (P2Y2R/P2Y4R agonist), and that P2Y2R is the mostly expressed nucleotide receptor in FDB muscle (as we previously described), a relevant role of P2Y2R in controlling protein synthesis in skeletal muscles is proposed. This proposed pathway could have a fine‐tuned role in the regulation of muscle mass during the integrated musculoskeletal activity.Support or Funding InformationFunded by Fondecyt‐1151353(SB)‐1151293(EJ)‐CONICYT‐PCHA‐63140009(CM)‐21151035(MA‐C).This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Cerebral Hyperperfusion and Metabolic Regulation in Response to Hypoxia: Do ATP‐Sensitive Potassium Channels Play a Role?
Authors: Alves Marcos Paulo Rocha , Campos Monique Opuszcka , Mattos João Dario , Mansur Daniel Elias , Rocha Helena , Secher Niels Henry , Nóbrega Antonio Claudio , Fernandes Igor Alexandre 
Published: June 2021

ATP‐sensitive K+ channels (K+ATP) mediate hypoxia‐induced cerebral vasodilatation and hyperperfusion in animals, a compensatory mechanism that maintains the oxidative metabolic stability of the brain. We then tested whether K+ATP blockade attenuates the increase in cerebral blood flow (CBF) in humans and leads to a shift towards brain non‐oxidative metabolism during isocapnic hypoxia (IH). Seven men (25 ± 4 yrs.) were exposed to 5‐min of normoxia and IH (10% O2) before (BG) and 3 h after Glibenclamide oral administration (AG – 5 mg). Invasive mean arterial pressure (MAP), radial artery and right jugular venous blood saturation, oxygen (PO2) and carbon dioxide (PCO2) partial pressure, glucose and lactate levels, and internal carotid (ICA) and vertebral (VA) artery blood flow (BF, Doppler ultrasound) were quantified over the last 30 s. In another protocol, 5 male subjects (24 ± 4 yrs.) underwent the same procedures before (BPL) and 3 h after placebo ingestion (APL – 5 mg of starch). CBF ((ICA BF + VA BF)×2 (mL/min)), cerebral metabolic rate of O2 (CMRO2), oxygen‐glucose (OGI) and oxygen‐carbohydrate (OCI) indexes were determined in each trial. IH provoked similar arterial desaturation (ΔBG −18.3 ± 6.0 vs. ΔAG −17.9 ± 3.5%, p = 0.784) and PaO2 reduction (ΔBG −80.6 ± 4.8 vs. ΔAG −77.6 ± 9.0 mmHg, p = 0.351). MAP and PaCO2 remained unchanged under both conditions. Smaller increases in ICA (ΔBG +111 ± 94 vs. ΔAG +66 ± 68 mL/min, p = 0.021) and VA BF (ΔBG +44 ± 38 vs. ΔAG +26 ± 39 mL/min, p=0.035) were observed under K+ATP blockade. IH‐induced increase in CBF (ΔBG +310 ± 215 vs. ΔAG +184 ± 150 mL/min, p = 0.017) was attenuated and followed by a smaller increase in CMRO2 (ΔBG +18.9 ± 14.8 vs. ΔAG +4.5 ± 12.2 mmol/100 g/min, p = 0.015). There was no IH‐induced shift to cerebral non‐oxidative metabolism as OGI and OCI did not change. CBF and metabolic responses to IH did not differ between BPL and APL. Therefore, our findings indicate that K+ATP play a role in the human cerebral hyperemia and maintenance of the brain metabolic stability during isocapnic hypoxia.Support or Funding InformationCNPq, CAPES, FAPERJ, FINEPThis abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Postnatal Development of Hypoxic and Hypercapnic Ventilatory Responses in Coturnix Quail
Authors: Pratt Ashley E. , Song Monata , Bavis Ryan W. 
Published: June 2021

Newborn mammals generally exhibit a biphasic hypoxic ventilatory response (HVR) in which the initial increase in ventilation is followed by a progressive decline toward (or below) baseline; the magnitude of the secondary decline diminishes with age. Considerably less is known about postnatal development of the HVR in birds, although a recent study did not detect a biphasic HVR in nestling red‐winged blackbirds (Dzialowski et al., Am J Physiol 311:R1105–R1112, 2016). We used head‐body plethysmography to characterize the ventilatory responses of Coturnix quail chicks to 15‐min challenges of 11% O2 or 4% CO2 at 0–1, 3–4, and 6–7 days of age. The magnitude of the HVR increased with postnatal age (21±4, 35±3, and 42±4 % increase from baseline, respectively; mean±SEM, P<0.01). The HVR was biphasic at P0–1 and (to a lesser extent) at P3–4, but not at P6–7. In contrast, the magnitude of the hypercapnic ventilatory response decreased with age (76±8, 54±4, 31±3 % increase from baseline, respectively; P<0.001). The hypercapnic ventilatory response was characterized by a relatively sustained increase in ventilation in all age groups, suggesting that the biphasic ventilatory response is specific to hypoxia. Additional experiments assessed hypoxic hypometabolism, and decreased metabolic rate does not appear to explain the biphasic HVR in the youngest quail chicks. We conclude that newborn quail exhibit a biphasic HVR similar to that observed in newborn mammals.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.