bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nucleolar function is regulated by the mitochondrial protein sulfite oxidase (SUOX)
Authors: McFadden Emily J. , Baserga Susan J. 
Published: May 2022

Ribosome biogenesis occurs in the nucleolus and relies upon RNA Polymerase I (Pol I) transcription of the rDNA into rRNA. This process is critical for normal cells but is dysregulated in diseases such as Alzheimer’s disease and cancer. To date, however, we have not yet explored the potential relationship between nucleoli and mitochondria. Mitochondria are critical for cellular energy and mitochondrial disorders exhibit dysregulation of nutrient and energy homeostasis. Like nucleoli, mitochondria are also dysregulated in Alzheimer’s disease and cancer, suggesting we may have overlooked a regulatory relationship between these two organelles.In pursuing novel regulators of nucleoli number and function, we have identified a mitochondrial protein that when individually depleted by siRNA in breast epithelial cells (MCF10As) causes a change in nucleolar number – sulfite oxidase (SUOX). Upon SUOX depletion, the nucleolar number decreases from the typical 2‐3 nucleoli to 1 nucleolus. SiRNA‐mediated SUOX depletion reduces nucleolar rRNA levels in a high‐throughput 5‐EU assay (Bryant et al. 2021) and reduces global protein translation by a puromycin incorporation assay, indicating defective nucleolar function. Furthermore, combined metabolomic and transcriptomic analyses following siRNA‐mediated SUOX depletion reveal disruption in the activated methyl cycle, consistent with aberrant ribosome biogenesis. Experiments are underway to validate defective methylation experimentally at specific steps in ribosome biogenesis. The glutamate cycle is also disrupted, congruent with the presentation of the recessive nervous system disorder Isolated Sulfite Oxidase Deficiency (ISOD). Thus, we have defined a novel mitochondrial regulator of nucleolar number and function, nucleolar rRNA biogenesis, and protein translation with implications in human disease. Our work will open up a new avenue of nucleolus‐mitochondria relationships and regulation, and potentially connect mitochondrial disorders with ribosome biogenesis as well as identify how mitochondrial homeostasis is critical for nucleolar function.
Activating P2Y1receptors improves function in arteries with repressed autophagy
Authors: Cho Jae Min , Park Seul‐Ki , Kwon Oh Sung , La Salle D. T. , Cerbie James , Fermoyle Caitlin C. , Morgan David , Nelson Ashley , Bledsoe Amber , Bharath Leena P. , Tandar Megan , Kunapuli Satya P. , Richardson Russell S. , Babu Pon Velayutham Anandh , Mookherjee Sohom , Kishore Bellamkonda K. , Wang Fei , Yang Tianxin , Boudina Sihem , Trinity Joel D. , Symons J. D. 
Published: May 2022

Objective and hypothesisThe importance of endothelial cell (EC) autophagy to vascular homeostasis in the context of health and disease is evolving. Earlier we reported that intact EC autophagy is requisite to maintain shear‐stress‐induced nitric oxide (NO) generation via glycolysis‐dependent purinergic signaling to eNOS. Here we illustrate the translational and functional significance of these findings.Methods and ResultsFirst, we assessed translational relevance using older male humans and mice that exhibit blunted EC autophagy and impaired arterial function vs. adult controls. Active hyperemia evoked by rhythmic handgrip exercise elevated radial artery shear rate similarly from baseline in adult (23±1 y) and older (68±2 y) subjects for 60‐min. Compared to baseline, indexes of autophagy initiation, p‐eNOSS1177 activation, and NO generation, occurred in radial artery ECs obtained from adult but not older volunteers. Regarding mice, indexes of autophagy and p‐eNOSS1177 activation were robust in ECs from adult (7 ± 1 months) but not older (23 ± 1 months) animals that completed 60‐min treadmill‐running. Further, results concerning the extracellular acidification rate (ECAR; Seahorse Bioanalyzer) indicate glycolysis and glycolytic capacity were elevated in response to 20 dyn/cm2 laminar shear stress x 45‐min in primary arterial ECs obtained from adult but not older mice. We next questioned whether the inability to initiate EC autophagy, glycolysis, and p‐eNOSS1177 precipitates dysfunction in arteries from older vs. adult mice. Compromised intraluminal flow‐mediated vasodilation displayed by arteries from older vs. adult mice was recapitulated in vessels from adult mice by : (i) NO synthase inhibition; (ii) acute autophagy impairment using 3‐methyladenine (3‐MA); (iii) EC Atg3 depletion (Atg3EC‐/‐ mice); (iv) purinergic 2Y1‐receptor (P2Y1‐R) blockade; and (v) germline depletion of P2Y1‐Rs. Importantly, P2Y1‐R activation using 2‐methylthio‐ADP (2‐Me‐ADP) improved vasodilatory capacity in arteries from : (i) adult mice treated with 3‐MA; (ii) adult Atg3EC‐/‐ mice; and (iii) older animals with repressed EC autophagy.ConclusionsArterial dysfunction concurrent with pharmacological, genetic, and age‐associated EC autophagy disruption is improved by activating P2Y1‐Rs.
Neuronal Activity Differentially Regulates KCC2 Protein Expression at Distinct Neuronal Maturation Stages
Authors: Pethe Abhishek , Heimrich Bernd , Roussa Eleni 
Published: May 2022

The K+/Cl‐ co‐transporter 2 (KCC2), a protein exclusively expressed in neurons, facilitates the co‐transport of a K+ and a Cl‐ ion across the cell membrane. The developmental shift of GABAA receptor mediated responses from depolarizing to hyperpolarizing is mainly due to a developmental upregulation of KCC2. Moreover, in mature neurons, neuronal activity leads to a decrease in surface expression and phosphorylation of Ser940 residue of KCC2, thereby reducing its activity. KCC2 is additionally phosphorylated at Thr906 and Thr1007, which reduces KCC2 surface expression and thus activity.Given the important role of neuronal activity in regulating KCC2 expression, we sought to investigate the effect of pilocarpine or 4‐aminopyridine (4AP) treatment on KCC2 expression across different maturation stages of neurons using quantitative RT‐PCR, immunocytochemistry (ICC) and immunoblotting. We also investigated the three phosphorylation sites – Ser940, Thr906 and Thr1007 – of KCC2. Immature neurons (day in vitro 4) from embryonic day 18.5 mouse hippocampus were treated with pilocarpine or 4AP (100µM, 60 minutes). The results show that 4AP or pilocarpine treatment has no effect on KCC2 transcript or protein expression, compared to controls. Similarly, ICC and immunoblotting results showed that there was no change in the phosphorylation status of Ser940. ICC results also showed that the phosphorylation status of Thr906 and Thr1007 remained unaltered in immature neurons after pilocarpine treatment.In day in vitro 17 organotypic hippocampal slices cultured from postnatal day 2 mouse pups, immunoblotting showed that treatment with 4AP did not affect KCC2 protein expression. However, in day in vitro 35 organotypic hippocampal slice cultures, 4AP treatment reduced KCC2 whole protein expression.These results demonstrate that neuronal activity has a distinctive effect on KCC2 protein as the neurons mature, suggesting a differential regulation of KCC2 protein at different maturation stages.
Hemoglobin Glycation and Oxidative Stress Induce Functional Modification of Band 3 Protein in D‐Galactose‐Treated Erythrocytes: Double Effect of Quercetin
Authors: Spinelli Sara , Remigante Alessia G. D. , Dossena Silvia , Marino Angela , Morabito Rossana 
Published: May 2022

D‐Galactose (D‐Gal) is a reducing sugar whose concentration in the blood is very low (between 0.00008 and 0.00018 mmol/L). An abnormal accumulation of D‐Gal, which occurs in pathological conditions such as galactosemia or to reproduce experimental models such as aging, leads to an increase in oxidative events and the formation of advanced glycation end products (AGEs), known to alter erythrocyte homeostasis. Specifically, increased levels of glycated hemoglobin (A1c) and oxidative markers have a negative impact on the exchange capability of Band 3 protein (B3p), responsible for the chloride‐bicarbonate exchange, essential for erythrocyte function. Among the natural compounds that can counteract these glycation and oxidation phenomena, quercetin (Q), a flavonoid found in many fruits and vegetables, shows strong anti‐glycation and antioxidant power at low doses, both in vivo and in vitro.Based on this, the hypothesis of the present work is that Q counteracts A1c formation and increased oxidative stress induced by exposure to different doses of D‐Gal in two in vitro experimental models: galactosemia (low doses) and aging (high doses).Therefore, the aim of this study is to verify whether the anti‐glycation and antioxidant action of Q results in a restoration of B3p functionality, measured by the rate constant for SO4²⁻ uptake, slower and better detectable than Cl‐or HCO3‐.In this regard, rate constant of SO4²⁻ uptake, A1c levels, oxidative stress assessment (TBARS levels, ‐SH groups levels, GSH/GSSG ratio), were determined after 1h incubation of erythrocytes with or without Q (10 µmol / L) at 37°C, followed by 24 h exposure to low (0.1‐10 mmol/L) or high (50‐100 mmol/L) doses of D‐Gal at 25°C.Our results show that low doses of D‐Gal reduce the rate constant of SO4²⁻ uptake and increase A1c levels, but do not induce oxidative stress. In contrast, high D‐Gal doses accelerate the rate constant, increase A1c levels and oxidative stress. Furthermore, pre‐treatment with Q reduces A1c levels and oxidative stress, bringing the rate constant back to control values.In conclusion, we can confirm that: i) anion exchange through B3p is a useful tool to monitor the homeostasis of erythrocytes exposed to different concentrations of D‐Gal; ii) all selected doses of D‐Gal affect B3p function via different mechanisms, including glycation events (low doses) and oxidative events (high doses); iii) Q attenuates the D‐Gal effect, impairing the rate constant alterations by preventing A1c formation and reducing oxidative stress.This evidence suggests that Q could be a useful dietary supplement to prevent oxidative events and AGE‐mediated processes linked to disease.
The Composition of Bile Acids under Fatty Liver Model in Chicken
Authors: Yang Wen Yuan , Lin Yuan Yu 
Published: May 2022

Bile acids is synthesized by cholesterol in the liver and exert by two different pathways, classical and alternative pathway. Two major enzymes, CYP7A1 and CYP27A1 play regulatory roles in two pathways. CA (cholic acid) and CDCA (chenodeoxycholic acid) as known as the primary bile acids which means they are major products in these two pathways and then they can be modified by gut microbiome. After modifying, the metabolites are called secondary bile acids such as lithocholic acid (LCA)、deoxycholic acid (DCA). Some researchers found that total bile acids including primary and secondary bile acids elevate in serum from non‐alcoholic fatty liver (NAFL). However, the composition of bile acids in chickens upon fatty liver model is unclear.In current study, seven‐week‐old ISA chicken were assigned to two group, there are control group (C) (n=10) and cholesterol with low choline (CLC) group (n=10). The control group was fed with extra 0.05% choline and without cholesterol, the other group was fed with extra 2% cholesterol and without choline for six weeks to simulate as NAFL. After sacrificing, we collected serum and cecum contents to quantitation of bile acids by mass spectrometer and analyze gut microbiome by 16S amplicon sequencing. The gene expression pattern of bile acid synthetic enzymes and related transcription factors was also determined by real‐time PCR.The bile acids in serum, such as TCDCA (C:CLC=6080.15nM:14555.75nM)、TLCA (C:CLC=122.31nM:2122.62nM)、5β‐Cholenic Acid‐7α‐ol‐3‐one (C:CLC=1.04nM:3.87nM)、CDCA (C:CLC=3.93nM:38.13nM) are significantly elevated in CLC group and the bile acids in cecum contents such as, TLCA (C:CLC=109.8nM:8897.27nM)、TUDCA (C:CLC=15.82nM:985.0nM)、THDCA(C:CLC=718.72nM:3084.36nM)、LCA(C:CLC=4.32nM:22.88nM)、TDCA(C:CLC=10.12nM:172.28nM) are significantly increased in CLC group. The results of gene expression showed that CYP7A1 and CYP8B1 were increased in CLC group compared than control. For gut microbiome, the proportion of bile acid tolerance bacteria Alistipes in the CLC group is 9.13% which is 1.69% higher than the control group.The pleiotropic roles of bile acid have gradually been valued. In this study, we analyzed the composition of bile acids under the fatty liver of chickens. We also found that the concentration of taurine conjugated bile acid in chickens is much higher than that of glycine.
Severe Diaphragm Fiber Weakness And Normal Response To Intraoperative Phrenic Stimulation In An ECMO‐Dependent Adult Receiving Lung Transplant
Authors: Smith Barbara K. , Machuca Tiago N. , Bresciani Guilherme , Mankowski Robert T. , Wohlgemuth Stephanie , Rackauskas Mindaugas , Pipkin Mauricio , Arnaoutakis George J. , Martin Tomas D. , Leeuwenburgh Christiaan , Ferreira Leonardo F. , Martin Daniel , Beaver Thomas M. 
Published: May 2022

IntroductionProlonged mechanical ventilation (MV) places patients at an increased risk for ventilator‐induced diaphragm dysfunction (VIDD), which can delay weaning from MV. We previously reported that intraoperative phrenic stimulation may preserve diaphragm fiber contractile function in those undergoing cardiac surgeries, but benefits are unclear in those with significant pulmonary disease who require extracorporeal membrane oxygenation (ECMO) support.Case DescriptionA 55‐year‐old male with end‐stage pulmonary fibrosis underwent bilateral lung transplantation (LTX) after a two‐week pre‐operative hospitalization that included ECMO support. Phrenic stimulation commenced upon initial surgical exposure of the diaphragm, and supramaximal twitch stimulations were administered every 30 minutes to one hemidiaphragm over 136 minutes. The contralateral side served as an inactive control. Diaphragm biopsies of the LTX patient were acquired after 5 stimulations. Maximal single‐fiber diaphragm twitch force was then compared to nine male participants (56 (12) years) admitted for cardiac bypass or valvuloplasty surgery, who underwent 6 (1) bouts of unilateral intraoperative stimulation followed by diaphragm biopsy. In each subject, we tested maximal single‐fiber force on an average of 22 (4) slow‐ and 22 (3) fast‐twitch fibers.Compared to cardiac surgical patients, the LTX subject had increased slow fiber cross‐sectional area (CSA) (Control side, cardiac: slow 5166 (1645) mm2; fast 6792 (732) mm2; LTX: slow 6827 (1504) mm2; fast 6159 (1173) mm2). Diaphragm fiber CSA of the stimulated side trended higher in the LTX patient (slow: 8588 (1908) mm2, p=0.080 vs control side; fast: 7232 (1976) mm2, p=0.094 vs control). Specific force (absolute force normalized to fiber CSA) in LTX was reduced by ~32% in slow fibers and ~30% in fast fibers (Table), as compared to cardiac patients. Specific force of stimulated fibers trended higher for slow‐ but not fast‐twitch fibers in LTX; response to stimulation resembled that of cardiac surgical patients. The patient was extubated 26 hours post‐LTX, as compared to 12 (7) hours in the cardiac patients.Impact (Novelty and Importance)This novel model of functional electrical stimulation suggests that phrenic stimulation preserved fiber CSA in an ECMO‐dependent adult with pulmonary fibrosis. Phrenic stimulation increased maximal specific force in slow‐twitch fibers, but responding forces remained well below expected values. These findings suggest that critically ill adult recipients of LTX may require additional duration and volume of diaphragm training, whether through voluntary or evoked contractions, to recover functional inspiratory muscle strength post‐operatively.
Left ‐ Right Asymmetry of the Jugular Foramen in Multisuture Syndromic Craniosynostosis
Authors: Woolridge Katherine , Mussell Jason C. 
Published: May 2022

IntroductionApert and Crouzon syndromes are among the most common craniosynostosis syndromes found in children. Mutations have been found in the fibroblast growth factor receptor 2 (FGFR2) gene in both syndromes. Although different mutations, the common mutated receptor raises suspicion for its involvement in the cranial morphogenesis found in these syndromic craniosynostosis patients.The shapes of these children’s skulls have long been thought to be the result of early fusion of the synchondroses. The syndromic morphology of the skulls in these patients, in particular Apert, results from a combination of abnormal development of the skull base, neural tissue, and calvaria. Investigations of these effects has led multiple studies to find decreased volumes of the posterior fossa in craniosynostosis patients and effects on the basicranial foramina of the skull, in particular the jugular foramen.Craniosynostotic children develop elevated intracranial pressure (ICP), as well as, other complications such as hydrocephalus and tonsillar herniation related to this increased pressure and skull dysmorphology. Narrowing of the jugular foramen is a potential cause of venous hypertension and may contribute to the ICP.This study analyzes the size of the jugular foramina in an effort to relate the severity of the foraminal stenosis to timing of synchondroses fusion, seen earlier in Crouzon patients. Additionally, as right jugular foramina have been found to be larger than left in the general population, our study analyzes the right and left jugular foramen sizes in relationship to each other in each Apert and Crouzon patient.MethodsTwelve preoperative CT scans of individuals diagnosed with either Apert or Crouzon syndrome were individually segmented and volume of the right and left jugular foramina estimated in Avizo. Volumes were analyzed using Wilcoxon Rank Sum and Kruskal‐Wallis one‐way ANOVA tests in SPSS. Scatter plots of the ratio of right to left foraminal volumes were created using Excel. This study was conducted under LSUHSC IRB #920.Results and DiscussionInitial results found no significant differences between right and left jugular foramina, however, absolute measurement of volumes most often recorded larger volumes on the left, contrary to that seen in the normal population. Scatter plots revealed two distinct clusters based on ratio of left‐right asymmetry which may reflect a difference in diagnosis.
Systemic and local administration of vasopressin differently affect hemodynamic and respiratory parameters in normotensive and hypertensive rats
Authors: Proczka Michal , Trzciński Adam , Żera Tymoteusz 
Published: May 2022

IntroductionUpregulation of vasopressinergic system and increased chemoreflex activity contribute to essential hypertension. Vasopressin (AVP) V1a receptors (V1aRs) were found in the brain stem structures involved in the control of breathing and in the carotid bodies (CBs). It has also been shown that in normotensive rats intravenous (i.v.) and local (intra‐carotid, i.a.) AVP administration results in different hemodynamic and respiratory response.PurposeWe aimed at finding out how systemic (i.v.) and local (i.a.) administration of AVP affects cardiorespiratory system via V1aRs in normo‐ and hypertensive rats and if V1aRs are expressed in CBs in spontaneously hypertensive (SHR) and normotensive Wistar‐Kyoto (WKY) rats.MethodsThe study was performed on urethane‐anesthetized adult male WKY (n=7) and SHR rats (n=7). Animals were implanted with vascular catheters into femoral vein (i.v. infusions), femoral artery (hemodynamic parameters) and external carotid artery (local infusions), as well as the tracheal tube (respiratory parameters) and subcutaneous ECG electrodes. After obtaining baseline parameters, the arterial chemoreflex was triggered with i.v. administration of potassium cyanide (KCN) (30 μg/100 μL). Bolus of AVP was given i.v. (10 ng/100 μL) and i.a. (5 ng/50 μL). After stabilization of hemodynamic and respiratory parameters, V1a receptor was blocked by administration of V1aR antagonist (d(CH2)51,Tyr(Me)2,Arg8)‐Vasopressin; 5 μg/100 μL) and AVP and KCN infusions were repeated. After measurements, carotid bodies (CBs) were collected and immunostained for V1aRs and visualized with confocal microscopy.ResultsResting mean arterial blood pressure (MABP), heart rate (HR) and minute ventilation (MV) were significantly higher in SHR rats than in WKY control. In both groups hemodynamic and respiratory response to pharmacological trigger of the reflex occurred, however increase in MABP and MV were significantly greater in SHR than in WKY rats. Intravenous AVP administration caused an increase in MABP, but ventilatory inhibition only in SHR rats. Intra‐arterial AVP infusion caused a modest increase in MABP in both groups, but inhibition of ventilation only in SHR rats. Blockade of V1aR abolished the effects of both systemic and local AVP administration. Furthermore, V1aR antagonist decreased the pressor component of the chemoreflex, however it did not influence ventilatory response. Immunostaining revealed V1aRs in CBs in both groups.ConclusionsOur findings show that enhanced cardiorespiratory responses to activation of arterial chemoreflex and augmented pressor and ventilatory effects of systemic and local administrations of AVP are present in hypertensive rats and depend on V1aRs. Presence of V1aRs in CBs suggests that AVP may control cardiorespiratory system via arterial chemoreceptors.
Chronic Stress exacerbates Tau production in the 3xTg Alzheimer’s Disease Mice
Authors: Prabhu Saina , Burrage Emily , Simpkins James , Kelley Eric , Chantler Paul 
Published: May 2022

Alzheimer’s disease (AD) is the most prevalent type of dementia linked with progressive cognitive decline and behavioral impairment in humans. Currently, an estimated 6.2 million Americans are living with AD, and it is ranked as the 6th leading cause of death in the United States. AD is a multifactorial disorder associated with protein alterations, oxidative stress and neuroinflammation. A cumulative of these factors drive the AD pathogenesis stimulating neurons to produce excessive amounts of β‐amyloid protein (Aβ1‐42) and hyperphosphorylated tau proteins. The complex interplay among the abnormal Aβ1‐42and tau proteins lead to the development of senile plaques and neurofibrillary tangles in the hippocampus of the brain. Chronic psychosocial stress is a risk factor of dementia and is mediated by a pro‐oxidative microenvironment, a fundamental process associated with dementia. We have shown that the xanthine oxidase pathway plays a key role in the chronic stress‐induced cerebrovascular pathology. Thus, we test the hypothesis that chronic stress, using the unpredictable chronic mild stress (UCMS) model, will exacerbate tau pathology and thus, accelerate the early progression of AD. Further, we tested the hypothesis that blocking the xanthine oxidase pathway with febuxostat (Feb) will prevent this accelerated progression of AD.At 4 months‐of‐age, 3xTg mice were separated into 4 groups; AD control, AD control+Feb, AD+UCMS, AD+UCMS+Feb. UCMS was performed for 8 weeks, with or without Feb treated water (50mg/L). Mice were euthanized at 6 months‐of‐age and the harvested brains were flash frozen and stored at ‐80°C. Brains were homogenized to extract soluble and insoluble fractions of tau proteins using Western blot (WB) and normalized to GAPDH or B‐actin.At 6 months‐of‐age, UCMS accelerated total and phosphorylated tau protein expression by 83% (p<0.05) and 350% (p<0.001), respectively, compared to AD controls. Febuxostat prevented the increased expression of phosphorylated tau and lowered the total tau protein expression in the UCMS group. However, total tau protein expression remained higher compared to AD control levels. Thus, overall, these data suggests that chronic stress accelerates tau pathology in 3xTg mice partly through the xanthine oxidase pathway. We will further explore Aβ1‐42and xanthine oxidase in 3xTg brain homogenates at 6 and 9 months‐of‐age, to better understand how stress accelerates AD pathology.