bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sphingosine‐1‐Phosphate acutely modulates the CFTR (Cystic Fibrosis Transmembrane Regulator) transporter in an AMPK‐dependent manner
Authors: Malik Firhan Atir , Meissner Anja , Bear Christine , Bolz Steffen Sebastian 
Published: June 2021

IntroductionSphingosine‐1‐Phosphate (S1P) is a primary modulator of resistance artery tone. Its bioavailability is controlled by a rheostat between sphingosine kinase 1 and intracellular S1P phosphohydrolase 1. We have found that the transport by CFTR is the rate‐limiting step for the intracellular hydrolysis of S1P. We hypothesized that S1P limits its own degradation by an AMPK‐dependent modulation of CFTR conductance.MethodsCFTR conductance was assessed using the iodide efflux technique (conventional and real‐time) in baby hamster kidney (BHK) cells, which stably express human wild type CFTR. AMPK phosphorylation was determined using Western blotsResultsBHK cells were found to endogenously express Sk1, SPP1 and the S1P1 and S1P2 receptors (n=8). S1P (1μM, n=6) significantly reduced iodide conductance by 43% (conventional) and 75% (real‐time). The negative effect of S1P on CFTR iodide conductance was enhanced following S1P2 overexpression but reduced following pretreatment with the S1P2 blocker JTE013 (5μM, n=6). The inhibitory effect of S1P was associated with AMPK phosphorylation and blocked by the AMPK inhibitor Compound C (80μM, n=5). Accordingly, AMPK activation by AICAR mimicked the effect of S1P on iodide conductance.ConclusionsThe S1P2‐ and AMPK‐dependent modulation of CFTR conductance describes a novel pathway through which S1P could potentially regulate its own degradation.
Effects of TMEM16A Expression on Motility and Metastasis in Epithelial Tumor Cells
Authors: Shiwarski Daniel John , He Lu Mei , Huang Xin , Gollin Suzanne , Grandis Jennifer , Duvvuri Umamaheswar 
Published: June 2021

TMEM16A, a novel gene that regulates Ca+‐activated Cl− currents, was recently isolated from oral cavity cancer cells. TMEM16A is overexpressed in several tumor types; however, the role that TMEM16A plays in promoting tumor motility remains unclear. The goal of this project was to characterize the role of TMEM16A in cancer cell motility, invasion, and metastasis. We hypothesized that TMEM16A contributed to tumor cell motility and may be an important factor in metastasis through epithelial to mesenchymal transition (EMT) in cancer. SCCHN and T24 bladder cancer cell lines were transduced with lentiviral particles encoding RNAi against TMEM16A, and stable cell lines overexpressing TMEM16A were also created. To assess motility we used trans‐well migration and scratch assays with agonists and inhibitors of TMEM16A. As hypothesized, overexpression of TMEM16A decreased motility and these results were confirmed using a dominant inactive construct. We further evaluated TMEM16A levels in primary and metastatic cell lines. Metastatic lines had reduced TMEM16A levels compared to paired primary cell lines. In summary, our results provide novel insights into the biologic function of TMEM16A in tumor motility and metastasis. This research has significantly enhanced our understanding about the pathogenesis of epithelial tumors, and can potentially be translated to many cancer types.Funded by:SPORE H&N Career Development Award (U.D.)Department of Otolaryngology Startup Funds (U.D.)SPORE H&N P50 CA 0A097190
Insulin stimulation of the epithelial sodium channel is inhibited by COMMD1
Authors: McDonald Fiona Jean , Swart Marianne , Ke Ying 
Published: June 2021

The epithelial sodium channel (ENaC) transports Na+ into epithelial cells located in the distal nephron, lung, and colon. Active channel number at the cell surface is regulated by ubiquitin modification and endocytosis. Insulin, aldosterone and vasopressin enhance Na+ transport via the serum and glucocorticoid regulated kinase (SGK1) that inactivates the ubiquitin ligase Nedd4‐2 that downregulates ENaC. Previously we reported that COMMD1 (copper metabolism Murr1 domain containing protein 1) inhibits ENaC amiloride‐sensitive current. Here the objective was to determine if COMMD1 and ENaC are coexpressed in kidney, and to study the mechanism by which COMMD1 inhibits ENaC amiloride‐sensitive current. Using immunohistochemistry COMMD1 was found to be widely expressed in the kidney, and to co‐localise with ENaC. Biochemical and electrophysiological assays showed that COMMD1 increased ubiquitin modification of ENaC and decreased its cell surface expression. COMMD1 abolished insulin‐stimulated amiloride‐sensitive current. COMMD1 co‐immunoprecipitated with SGK1 and Akt1, but not Nedd4‐2. Knock‐down of COMMD1 enhanced the effect of SGK1 and Akt1 on amiloride‐sensitive current, but did not change the effect of Nedd4‐2. In conclusion, COMMD1 regulates ENaC cell surface expression via Nedd4‐2.Support from the Marsden Fund Council from Government funding administered by the Royal Society of New Zealand
Dietary choline affects strength gains in elderly people
Authors: Lee Chang Woock , Lee Teak V. , Chen Vincent C.W. , Bui Steve , Riechman Steven E. 
Published: June 2021

BackgroundCholine is a precursor to acetylcholine, which transmits neural signals to skeletal muscle. Thus, dietary choline may affect muscle contraction and exercise performance by mediating availability of acetylcholine at the neuromuscular junction. We examined the effects of choline consumption on muscle responses to resistance exercise training (RET) in the elderly.MethodsTwo groups of healthy untrained 50–69 year old men and women underwent 12 weeks of RET (3x/week, 3 sets, 8–12 reps, 70% of 1 Repetition Maximum (1RM)). Each group consumed <350 mg/day (Low, mean=210.1±20 mg/d, n=17) or >350 mg/day (Adequate, mean=461.7±19 mg/d, n=19) of dietary choline during the study period. Body composition and maximum strength were measured before and after training.ResultsSignificant differences in strength (leg press 1RM + chest press 1RM) gains were observed between the groups (Low: 49.3±12kg vs. Adequate: 88.8±11kg, p<0.05/Low: 22.8±7% vs. Adequate: 46.8±7%, p<0.05) with ANCOVA analysis (covariate: gender) which was consistent with regression analysis (β=0.376, r2= 0.187, p<0.01). There was no difference in lean mass gain between the groups (Low: 1.49±0.3kg vs. Adequate: 1.92±0.3kg, p>0.05).ConclusionThese results suggest that variability of dietary choline intake may affect strength gains in elderly people possibly through its effect on neurotransmitter (acetylcholine) availability.
Aging induced alterations in carotid baroreflex control of arterial blood pressure at rest and during dynamic exercise in humans
Authors: Fisher James P , Kim Areum , Young Colin N , Fadel Paul J 
Published: June 2021

The arterial baroreflex is fundamental for evoking and maintaining appropriate cardiovascular adjustments to exercise. Given that exercise‐induced blood pressure (BP) responses appear exaggerated in older individuals, we sought to investigate how aging influences carotid baroreflex (CBR) regulation of BP during dynamic exercise. BP and heart rate (HR) were recorded at rest and during leg cycling performed at 50% HR reserve in 6 young (23±1 yr) and 6 older (60±1 yr) healthy men. Five second pulses of neck pressure and neck suction from +40 to −80 Torr were applied to determine the maximal gain (GMAX) of the full CBR function curve and examine baroreflex resetting during exercise. GMAX was similar in both groups at rest and during exercise. However, in older subjects the operating point (OP) of the modeled function curve was located further away from the centering point (CP) and towards the reflex threshold, both at rest (OP minus CP; −12±3 vs. −3±4 mmHg, older vs. young, P<0.05) and during exercise (OP minus CP; −10±2 vs. 0±3 mmHg, older vs. young, P<0.05), compared with the younger group. In addition, the magnitude of CBR resetting was ≈40% greater in older individuals. These findings suggest that both at rest and during dynamic exercise, the ability of the CBR to defend against a hypotensive challenge is reduced with increased age, while the magnitude of exercise CBR resetting is augmented.Supported by NIH RO1HL093167
Stimulation of the Efferent Vagus Nerve Mitigates Acute Lung Injury and Ventilator Induced Lung Injury
Authors: Dos Santos Claudia , Shan Yuexin , Akram Ali , Peng Claudia , Slutsky Arthur S , Haitsma Johannes 
Published: June 2021

RationaleVentilator induced lung injury (VILI) significantly contributes to the mortality in patients with acute respiratory distress syndrome.ObjectivesTo determine the role of vagus nerve signaling in VILI.MethodsTo determine whether vagus signaling plays a role in VILI we first demonstrated that disruption of the CAP reflex by bilateral vagotomy results in worsening lung injury in a mouse model of high‐volume‐induced lung injury. In a clinically relevant model of injurious mechanical ventilation following lung injury induced by hemorrhagic shock/resuscitation we then tested the hypothesis that electrical and pharmacological stimulation of the vagus nerve can attenuate lung injury in rats.ResultsVagotomy exacerbates lung injury from high volume ventilation in mice as demonstrated by increased wet‐to‐dry ratio, infiltration of neutrophils in bronchoalveolar lavage fluid and lung tissues, and increased tissue levels of interleukin‐6. Vagotomy exacerbated while vagus stimulation attenuates lung injury in rats after ischemia reperfusion injury ventilated with either high or low volume strategies. Treatment of both mice and rats with the vagus mimetic drug, semapimod, resulted in decreased lung injury. Vagotomy also increased pulmonary apoptosis whilst vagus stimulation attenuated VILI‐induced apoptosis. In‐vitro studies suggest that vagus‐dependent effects on inflammation and apoptosis are mediated via the alpha 7 subunit of the acetylcholine nicotinic receptor effect on cyclic stretch‐dependent singling pathways c‐jun N‐terminal kinase (JNK) and Fas (TNF receptor superfamily, member 6).ConclusionStimulation of the cholinergic anti‐inflammatory reflex may represent a promising alternative for the treatment of VILI.
Respiratory responses to NaHS are mediated by central mechanisms
Authors: Yu Jerry , Li Huafeng , He Yuwen , Walker Jerome 
Published: June 2021

Hydrogen sulfide, H2S, is a gasotransmitter that serves a variety of important physiological functions. On the other hand, it also produces fatal toxicity. Respiratory arrest is major cause of death; however, the underlying mechanism remains unclear. In the current study, we recorded phrenic nerve activity to monitor the central respiratory output in anesthetized, open chest, mechanically ventilated rabbits and examined the respiratory response to intravenous as well as lung parenchymal injection of sodium hydrogen sulfide, NaHS. Intravenous injection of NaHS caused immediate hyperpnea and tachypnea, which was followed by apnea. These respiratory responses were sustained after bilataral vagotomy, indicating they are the result of extra‐vagal mechanisms such as direct central effect through the circulation. This statement was further strengthened by the fact that intraparenchymal NaHS injection produces hyperpnea and tachynea but not apnea when the ipsilateral pulmonary artery was occluded. Apnea ensued after releasing the occlusion. We conclude that the respiratory responses to H2S exposure are mainly centrally mediated. Apnea as well as tachypnea and hyperpnea are caused by direct action of the CNS, although the vagal afferents may also contribute to the early hyperpnea and tachypnea responses.Supported by NIH (HL‐58727)
Galanin reduces cardiac vagal acetylcholine release and bradycardia via a GalR1, protein kinase C dependent pathway
Authors: Herring Neil , Cranley James , Lokale Michael N , Habecker Beth , Paterson David J 
Published: June 2021

Prolonged cardiac sympathetic nerve activation releases slowly diffusing co‐transmitters such as Galanin (Gal). We tested the hypothesis that Gal acts on local vagal neurons to reduce acetylcholine release and vagal bradycardia.The GalR1 receptor was immunofluorescently co‐localized with choline acetyl‐transferase containing neurons in guinea pig right atria. The effect of Gal was established on the heart rate (HR) response to vagus nerve stimulation (VNS) in isolated guinea pig sinoatrial node/right vagus nerve preparations and also on 3H‐acetylcholine release from right atria during field stimulation. Gal (n=6) reduced the HR response to VNS at 1, 3 and 5Hz (significant at ≥100nM, p<0.05) but not to the stable analogue of acetylcholine, carbamylcholine (n=6). Gal (500nM, n=5) also significantly attenuated the release of 3H‐acetylcholine during field stimulation. The effect of Gal (100nM) on vagal bradycardia was abolished by the GalR1 antagonists galantide (100nM, n=5) and M40 (100nM, n=4) and also by the protein kinase (PK) C inhibitor calphostin C (100nM, n=5). The PKA inhibitor H89 (500nM, n=5) did not prevent the effect of Gal on vagal bradycardia. These results show that GalR1 is located on atrial cholinergic neurons and that Gal attenuates vagal bradycardia via a reduction in acetylcholine release mediated by a GalR1, PKC dependent pathway.Supported by the British Heart Foundation
MicroRNA expression with “aging” in human aortic endothelial cells
Authors: Blimline Mark , Seals Douglas R. , Donato Anthony J. , Fleenor Bradley S. , Rippe Catarina 
Published: June 2021

Vascular endothelial cell “aging” is associated with development of a senescent phenotype featuring oxidative stress, inflammation, increased extracellular matrix (ECM) and collagen deposition, and impaired angiogenesis. We hypothesized changes in micro‐RNAs (miR) known to modulate expression of proteins associated with these altered functions in human aortic endothelial cells (HAEC) with aging. HAEC aged to replicative senescence (45±1 population doublings (PDLs)) had greater % of cells stained for senescence‐associated β‐galactosidase (60±7% vs. 7±1%), expression of collagen I (+5.0±0.04‐fold, P<0.05) and vascular cell adhesion molecule‐1 (VCAM‐1, +3.6±0.8‐fold, P<0.05) protein (western blotting), and superoxide production (+2.7±0.3‐fold, P<0.001) (electron paramagnetic resonance) vs. early passage HAEC (28.0±0.4 PDLs). Consistent with these changes, senescent HAEC had lower expression of: collagen‐repressing miR‐29 (0.2±0.1 vs. 1.0±0.3 AU, P<0.05); miR‐21 (0.4±0.1 vs. 1.0±0.2 AU, P<0.05) and miR‐214 (0.3±0.1 vs.1.0±0.3 AU, P<0.05), two miRs that target PTEN, a tumor suppressor and cell cycle regulator; and miR‐126 (0.5±0.2 vs. 1.0±0.1 AU, P<0.05), which induces angiogenesis and down‐regulates VCAM‐1. In contrast, redox‐sensitive miR‐125 was greater in senescent HAEC (2.2±0.4 vs. 1.0±0.3 AU, P<0.05). Changes in miR may play an important role in development of a senescent phenotype in vascular endothelial cells and contribute to arterial endothelial dysfunction and increased risk of cardiovascular diseases with aging.NIH AG013038, AG029337, HL007822, Swedish Research Council
Apolipoprotein E Suppresses Atherosclerosis by Reducing Leukocyte Recruitment to Atheroma
Authors: Gaudreault Nathalie , Kumar Nikit , Possada Jessica , Raffai Robert 
Published: June 2021

We investigated the anti‐atherosclerotic properties of apoE beyond its ability to lower plasma cholesterol level. We hypothesized that in the setting of dyslipidemia, apoE reduces the recruitment of leukocytes to atheroma.Mice developing spontaneous dyslipidemia in the presence and absence of apoE expression were studied: Hypomorphic apoE mice deficient in low‐density lipoprotein receptor (Apoeh/hLdlr−/−) were compared to mice deficient in apoE and Ldlr (Apoe−/−Ldlr−/−). Despite similar plasma cholesterol levels (597.5±24.3 mg/dl versus 662.4±26.4 mg/dl, respectively), Apoeh/hLdlr−/− mice developed ~4 fold less oil red O and ~3 fold less macrophage‐positive aortic surface area than Apoe−/−Ldlr−/− mice by five months of age.To examine the role of apoE on leukocyte recruitment, we performed adoptive transfer of fluorescently‐labeled leukocytes in both mouse models. Cross‐sections of the aortic root and isolated enface aortic arch were examined by confocal microscopy. Shoulder regions of aortic lesions accumulated two fold more fluorescent‐leukocytes in Apoe−/−Ldlr−/− than in Apoeh/hLdlr−/− mice. Moreover, the endothelium of Apoe−/−Ldlr−/− mice displayed elevated levels of PECAM and JAM‐A.Taken together these results indicate that apoE reduces atherosclerosis by suppressing the expression of cell‐adhesion molecules on the endothelium and in turn the recruitment of leukocytes to atheroma.
Cooperative role of NF‐κB signaling and PARP‐1 activity in the TNF‐induced inhibition of PHEX gene expression
Authors: Kiela Pawel R , Majewski Pawel M , Thurston Robert D , Ramalingam Rajalakshmy , Sabetisoofyani Arash , Ghishan Fayez K 
Published: June 2021

Reduced bone mass is a common complication in chronic inflammatory diseases, although the mechanisms are not completely understood. Phex gene encodes an osteoblast Zn‐endopeptidase controlling bone mineralization and is inhibited by TNF in chemically‐induced colitis. Here, we confirm its downregulation in CD4+CD45RBhigh T‐cell transfer colitis, and delineate the molecular mechanism involved in TNF‐mediated inhibition of Phex transcription. TNF decreased expression of Phex in UMR106 cells and did not require de novo synthesis of a transrepressor. Transient transfections with Phex promoter constructs identified a region within ‐74nt containing weak putative NF‐κB binding sites. TNF induced recruitment of p65/p50 complex to two of those cis elements. Inhibition of NF‐κB signaling by a proteasome inhibitor increased the basal level of Phex transcription and abrogated the effects of TNF, while overexpression of p65 reduced promoter activity. Proteomic approaches identified poly(ADP‐rybose) polymerase (PARP‐1) constitutively interacting with Phex promoter, and TNF‐induced PARylation of p65 which potentiates its suppression of Phex transcription. TNF‐mediated downregulation of Phex was completely abrogated in PARP‐1 KO mice. NF‐κB signaling and PARP‐1 enzymatic activity are cooperatively involved in constitutive and inducible suppression of Phex.Grant support: R37DK033209 (F.K.G.)
Expression of filamin‐A during tooth development
Authors: Miyamoto Ryoko , Yamada Aya , Iwamoto Tsutomu , Nakamura Takashi , Fukumoto Satoshi 
Published: June 2021

Remodeling of the cytoskeleton is central to the modulation of cell shape and migration. Filamin‐A, encoded by the gene FLNA, is a widely expressed protein that regulates re‐organization of the actin cytoskeleton by interacting with integrins, transmembrane receptor complexes and second messengers. OPD1 belongs to a group of X‐linked skeletal dysplasias known as oto‐palato‐digital syndrome spectrum disorders that also include OPD2, Melnick‐Needles syndrome (MNS), and frontometaphyseal dysplasia (FMD). Recently, it has been demonstrated that mutations in the gene encoding the cytoskeletal protein filamin A (FLNA) are responsible for this group of clinically overlapping human syndromes. We identified the novel mutation in FLNA gene in MNS patient with tooth agenesis, root dysplasia and severe enamel hypoplasia. Mutation was observed in the rod domain (11th filamin repeat) of FLNA gene. In rodent tooth germ development, Filamin‐A was expressed in inner enamel epithelium and odontoblasts, but not other tooth cells. In cultured dental epithelial cells, filamin‐A localized under the cell surface and associated with F‐actin. These results indicate that filamin‐A is important for the organization of cytoskeleton and the differentiation of ameloblasts and odontoblasts.Grant Funding Source: Ministry of Education, Culture, Sports, Science and Technology of Japan
Assessing joint vibration during spinal manipulation
Authors: Cramer Gregory D. , Ross Kim , Pocius Judy , Cantu Joe , Laptook Evelyn , Fergus Michael , Gregerson Doug , Selby Scott , Raju P. K. 
Published: June 2021

This IRB‐approved study assessed the relationship between cavitation and zygapophysial (Z) joint gapping following spinal manipulation (adjusting) in 5 healthy volunteers. High signal MRI markers were used to accurately identify the T12, L3, and S1 spinous processes during scout views. Axial images of the L4/L5 and L5/S1 levels were obtained in the neutral supine position. Each subject was then positioned on the side, and accelerometers were placed over the marked spinous processes. Recording from the accelerometers was done from final positioning through adjusting. The subject was then scanned in side posture position (accelerometers removed). Using a digitizer, the greatest A‐P central Z joint articular surface distances were measured on the 1st and 2nd scans; the difference between the 2 measurement values was the gapping difference, GD; a positive value indicating an increase in gapping following the spinal adjustment. GD was compared between up‐side (adjusted), down‐side (non‐adjusted), cavitation, and non‐cavitation joints.ResultsGD was increased in Z joints that were adjusted [0.5 (SE 0.2) mm] vs. non‐adjusted [−0.2 (SE 0.2) mm], and vertebral segments with cavitation gapped more than no cavitation [0.8 (SE 0.4) vs. 0.4 (SE 0.2) mm].ConclusionsA future clinical study is quite feasible. Forty subjects would be needed for appropriate power (0.80). Funding: NIH/NCCAM (#2R01AT000123).
Effects of swimming exercise and diet in tibias of rats: a biomechanical study
Authors: Okubo Rodrigo , Fernandes Cleverson Rodrigues , Frajacomo Fernando Tadeu Trevisan , Farnesi Ana Paula , Cardoso Vinicius Kannen , Falcai Maurício José , Marine Tassiana , Fazan Valéria Paula , Shimano Antônio Carlos , Volpon José Batista , Garcia Sérgio Britto 
Published: June 2021

The purpose of this study was to evaluate the effects of swimming exercise in tibias of rats fed with different controlled diet. This study was approved by Ethical Committee in Animals Experiment. Ninety three‐month‐old male Wistar rats were randomly assigned to nine groups (n=10): (G1) normal diet control, (G2) hypo caloric diet control, (G3) hyper caloric diet control, (G4) normal diet 20‐minutes training, (G5) hypo caloric diet 20 minutes training, (G6) hyper caloric diet 20‐minutes training, (G7) normal diet 90‐minutes training, (G8) hypo caloric diet 90‐minutes training, e, (G9) hyper caloric diet 90‐minutes training. Hypo caloric diet is a 40% restriction of the total diet of the normal animals. Hyper caloric is 14% high‐fat diet. Normal diet is 4% fat. Physical exercise consisted of swimming on a large aquarium. Rats swam 5 days a week, 20 or 90 minutes, during 8 weeks. Tibias were dissected and tested in a universal testing machine. Data were analyzed using level of significance set at 5%. Data from our study suggest that bone resistance depends of the weight of animals acquired through diet. Swimming exercise programs did not alter mechanical properties of bones.Grant Funding Source: FAPESP