bluuebunny/crossref_metadata_2025_split huggingface dataset:
Valproic acid does not affect decreased insulin secretion in WFS1‐deficient pancreatic islets
Authors: Koks Sulev , Ivask Marilin , Hugill Alison , Terasmaa Anton , Plaas Mario , Vasar Eero 
Published: June 2021

Wolfram syndrome, an autosomal recessive disorder characterized by juvenile‐onset diabetes mellitus and optic atrophy, is caused by mutations in the wolframin (WFS1) gene. WFS1 negatively regulates endoplasmic reticulum (ER) stress signalling and therefore have a role in the pathogenesis of diabetes. Valproic acid (VPA), a widely used anticonvulsant and mood‐stabilizing drug, normalized the glucose intolerance in Wfs1 mutant mice, but had no effect on the course of glucose tolerance in wild‐type (WT) mice. The aim of this study was to investigate insulin secretion in isolated pancreatic islets of WFS1‐deficient (Wfs1KO) mice and also evaluate insulin secretion in the presence of VPA. In addition, the content of proinsulin in the isolated islets was measured. In general Wfs1KO pancreatic islets secreted less insulin compared to WT and Wfs1HZ islets. Differences in proinsulin amount were not statistically significant although there was a trend that Wfs1KO had an increased level of proinsulin. We found significantly reduced insulin secretion in Wfs1 mutants and no effect of VPA treatment.This study was supported by the Frontiers of Functional Genomics and by The European Regional Development Fund.
EXPRESSION AND ACTIVITY OF NEUTRAL SPHINGOMYELINASE IN THE KIDNEY OF DIABETIC RATS.
Authors: del Rocio Bautista María , del Valle‐Mondragón Leonardo , Cano‐Mártinez Agustina , Mercado Adriana , Franco Martha , Zarate‐Calleja Efren 
Published: June 2021

BackgroundSphingomyelinases (SMase) are enzymes that specifically catalyze the hydrolysis of sphingomyelin into ceramide. An increase in tissue ceramide could result from either increased ceramide production (such as, SMase mediated sphingomyelin hydrolysis), or decreased ceramidase activity. However, the role of sphingolipids and key enzymes of sphingolipids metabolism in diabetes are not well understood. The purpose of this study was to determine the ceramide concentration, expression and activity of SMase in the kifney of diabetic rats.MethodsThe rats were divided into two groups: control and diabetic rats (n=10 each). Diabetes was induced by intraperitoneal injection of streptozotocin (STZ) at 60 mg/kg body. After a followup of 4 weeks, rats were sacrificed and kidney tissue samples were processed and stored as needed. The ceramide generation and the expression of neutral‐SMase were measured by immunohistochemistry. N‐SMase activity was monitored indirectly using 10‐acetyl‐3,7‐dihydroxyphenoxazine, a sensitive fluorogenic probe for H2O2.ResultsFour weeks after treatment with STZ, in the kidney of diabetic rats increase the ceramide concentration. Conversely, the expression and activity of N‐SMase were lower en the kidney of diabetic rats than those of the control groups.ConclusionsThese results suggest that nSMase did not increase the ceramide content in the kidney of diabetic rats.
Role of Transient receptor potential vanilloid 4 in neutrophil activation and acute lung injury
Authors: Tang Christine , Yin Jun , Kuebler Wolfgang M 
Published: June 2021

IntroductionTransient receptor potential vanilloid 4 (TRPV4) is a cation channel expressed in lung parenchyma and inflammatory cells. TRP channels have been implicated in the activation of inflammatory cells and the pathogenesis of acute lung injury (ALI), thus we hypothesized that TRPV4 deficiency or inhibition may attenuate inflammatory responses and ALI.MethodTo test this, in vivo and ex vivo studies were performed using TRPV4−/− mice.ResultsGenetic deficiency or pharmacologic inhibition of TRPV4 attenuated the functional, histological and inflammatory hallmarks of ALI following intratracheal instillation of hydrochloric acid or lipopolysaccharide (LPS). TRPV4−/− compared to TRPV4+/+mice had an increased survival rate following i.p. LPS. Perfused lung studies showed decreased lung weight increase in TRPV4−/− mice in response to platelet activating factor (PAF). Transfusion of TRPV4+/+ vs. TRPV4−/− blood into perfused lungs led to greater Evans blue extravasation following PAF administration. Neutrophils from TRPV4−/− mice had attenuated increases in intracellular calcium and reactive oxygen species and showed reduced endothelial transmigration in response to PAF.ConclusionOur findings identify a role for TRPV4 in neutrophil activation, and suggest TRPV4 as a promising pharmacological target for the prevention and potentially treatment of ALI.Supported by CREMS, University of Toronto and NSFC # 81000028
TrkB kinase activity is necessary for spontaneous recovery of ipsilateral rhythmic phrenic activity following cervical spinal cord hemisection
Authors: Zhan Wen‐Zhi , Mantilla Carlos , Sieck Gary 
Published: June 2021

Following unilateral C2 spinal hemisection (SH), descending excitatory drive to phrenic motoneurons is disrupted causing ipsilateral diaphragm muscle paralysis. After SH, there is gradual recovery of phrenic nerve activity reflecting neuroplasticity. We hypothesized that this neuroplasticity is dependent on BDNF signaling via its TrkB receptor and kinase activity. In this study we used TrkB(F616A) knockin mice, that permit rapid and selective inhibition of TrkB kinase activity by 1NMPP1. Adult TrkB(F616A) mice were treated with 1NMPP1 (25 μM) or vehicle in the drinking water starting 3 days post‐SH. At the terminal experiment, bilateral diaphragm EMG was monitored to determine the proportion of animals displaying recovery of ipsilateral phrenic activity. At 3 days post‐SH, no animals displayed ipsilateral diaphragm EMG activity (0/10). At 14 days post‐SH, 40% (6/15) of TrkB(F616A) mice displayed ipsilateral phrenic activity, although EMG amplitude remained substantially below contralateral levels. Following 1NMPP1 treatment, no animals displayed ipsilateral diaphragm EMG activity (0/10; p<0.05). In control, wild‐type mice, 1NMPP1 treatment (for 11 days) had no evident effect on bilateral diaphragm EMG activity (n=7). These results support an essential role for TrkB kinase activity in the spontaneous recovery of rhythmic phrenic activity post spinal cord injury.Supported by NIH grant HL096750.
AMP‐Kinase (AMPK) stimulation improves lung function and survival in a rat model of LPS‐induced lung injury
Authors: Jian Ming‐Yuan , Creighton Judy 
Published: June 2021

Using isolated lungs, we demonstrated previously that activation of AMPK attenuated injury in a pharmacologically‐induced model of microvascular damage. LPS is known to damage the lung's microcirculation resulting in increased edema. We reasoned AMPK stimulation would improve lung function in LPS treated animals. Rats were given LPS by intraperitoneal injection (IP). One group also received AMPK activator by IP 6 hr later. Permeability was assessed via Kf measurements at 24 hr post LPS treatment. Following experiments, lungs were fixed and stained for morphometric analysis. LPS caused a 2.2 fold increase in Kf at 6hr and a 3.1 fold increase at 24 hr. Histology revealed diffuse capillary injury with thickened alveolar walls and intra‐alveolar exudates in LPS treated lungs. AMPK stimulation using metformin or AICAR following LPS‐induced injury significantly attenuated alveolar damage and decreased Kf. Furthermore, AMPK activation increased survival in LPS treated animals. 30 % of LPS treated animals died, whereas no animals in the control or metformin/AICAR treated groups died.ConclusionAMPK stimulation using clinically approved drugs reverses lung injury. Supported by HL102296 and HL 110803.
Protease‐activated receptor 2 (PAR2) inactivates the pro‐apoptotic protein, BAD, via ERK1/2 and PI3K activity to decrease apoptosis in colonic epithelial cells
Authors: Iablokov Vadim , Hirota Christina Lynn , MacNaughton Wallace Keith 
Published: June 2021

Colonic biopsies from inflamed colon have higher levels of epithelial apoptosis than biopsies from healthy individuals. Therapies that decrease intestinal epithelial apoptosis may decrease the inflammation observed in inflammatory bowel disease. We previously showed that signaling by PAR2, a GPCR activated by serine proteases, delayed IFN‐γ & TNF‐α‐induced apoptosis in colonic epithelial (HT‐29) cells. We aimed to determine the mechanism responsible for PAR2‐induced survival. The PAR2 agonists 2‐furoyl‐LIGRLO (2fLI), SLIGKV and trypsin all significantly reduced cleavage of caspase‐8, 9, 3 as well as PARP in response to IFNγ/TNFα. 2fLI increased phosphorylation of ERK1/2, p90RSK and Akt. 2fLI treatment stimulated the phosphorylation of pro‐apoptotic BAD at Ser112 and Ser136. Selective MAPK pathway inhibitors (U0126 & SL0101) blocked BAD Ser112 phosphorylation, whereas the PI3K‐selective inhibitor (LY294002) blocked BAD Ser136 phosphorylation. Pre‐treatment with 2fLI prior to the addition of IFNγ/TNFα increased BAD phosphorylation at both residues. PAR2 signaling reduces epithelial apoptosis in response to inflammatory cytokines via activation of pathways that inactivate the pro‐apoptotic BAD protein. Our findings may represent a mechanism whereby proteases facilitate epithelial cell survival and colonic healing after inflammation.Funding: Crohn's and Colitis Foundation of Canada
Bringing Augmented Reality to a Metabolic Pathways Puzzle
Authors: Galembeck Eduardo , Magrini Márcio L , Anderson Trevor 
Published: June 2021

During several years of using a paper puzzle to introduce students to the principles of metabolic pathways, we noticed that both the number of instructors and the time they spend with the students, plays a major role in the success of the activity. An insufficient number of instructors does not permit adequate contact with all the students, which both frustrates and discourages them. To bring this activity to larger audiences, while involving only a few instructors, we added a technological tool called augmented reality to the paper puzzle, turning it into a game. One of the game goals is still to assembly the puzzle, but by using an app that runs in a tablet, the students can now check their achievements as they progress through the activity. The app also includes answers to some of the frequently asked questions, while the augmented reality permits the addition of more information to the cards, via virtual flashcards. The virtual flashcards displayed on the tablet screens show information such as the molecular 3D structure, and clues for assembling the puzzle. The abovementioned technological improvement to the paper puzzle has enabled its use in larger classrooms with fewer instructors, but we still recommend also using the paper cards with students playing in groups as a powerful way of promoting student learning about metabolic pathways.This research was partially supported by FAPESP and CNPq, Brazil.
From anatomy to acoustics, a study of the sound generation process in baleen whales (mysticetes)
Authors: Cazau Dorian , Adam Olivier , Laitman Jeffrey , Reidenberg Joy 
Published: June 2021

The mechanism of baleen whale (mysticete) sound production is a topic of much interest, particularly as they make the loudest natural sounds and transmit them across the longest distances. Prior studies on mysticete sound generation have explored either acoustics or anatomy, but unfortunately have done so in isolation of the other discipline. This study links the two disciplines to derive a comprehensive understanding of the sound production process. Anatomical data (vocal fold measures, respiratory tract volumes, air flow paths) are used to derive initially an acoustic model that explains how sounds are made and transmitted. The model is then tested by comparisons to parameters (frequency, amplitude, duration) derived from hydrophone recordings of live whales. The model defines four mutually exclusive components: air sources (providing initial energy), vibrators generating harmonic frequencies (vocal folds, corniculate flaps), air flow paths (between lungs, trachea, laryngeal sac, nasal cavities), and radiating areas (transmitting sound energy to water). This model explains, for the first time, the acoustic function of each part of the mysticete sound generating system.Grant Funding Source: AAA
Study of the anatomic variations of the pyelocaliceal system
Authors: Vergamini Lucas Bonachi , Menegazzo Gian Luigi Martins , Barros Mirna Duarte , Pinto Antonio Cardoso 
Published: June 2021

Introduction and PurposeMany are the anatomical variations of the pyelocaliceal system, which influence the arterial irrigation and venous drainage. This study adopted a classification given by Sampaio in “Anatomia Renal para Urologia”. The system is divided in: Type A‐I has the mesorenal region drained by chalices from the superior or inferior caliceal group. Type A‐II has the mesorenal region drained by crossed chalices from both superior and inferior caliceal groups. Type B‐I has the mesorenal region drained by an independent caliceal group. Type B‐II has small chalices that drain the mesorenal region directly to the renal pelvis. The study aims to describe the structure of the pyelocaliceal system and its variations. Compare findings with those found in literature.MethodsKidneys obtained from adults that belong to the Morphology Department of Faculdade de Ciênicas Médicas da Santa Casa de São Paulo were injected with resin through the ureter and later corroded by acid. Kidneys obtained from someone who had nefropathy were excluded.Results52 kidneys were obtained. 39.6% were type A‐I. 12.5% were type A‐II. 18.8% type B‐I and 29.2% type B‐II.ConclusionResults were similar to the ones found in Brazilian population studies. Many are the anatomic variations of the pyelocaliceal system and they must be considered especially involving surgical procedures.
Associations between localized variation in brain anatomy and social behavior in healthy human subjects
Authors: Loyet Mackenzie , Schoenemann P. Thomas , Avants Brian B , Gee James C 
Published: June 2021

Understanding the relationship between brain structure and function is critical for interpreting evolutionary changes in the human brain. It has been suggested that social environments play a key role in this process and brain size has been shown to correlate with social group size across primate species (Dunbar, 1998). Studies have indicated a disproportionate elaboration in areas of the prefrontal cortex in hominin evolution (Schoenemann, 2005). The prefrontal cortex is known to be relevant to social decision making, which suggests that selection for social ability may have played a significant role in prefrontal elaboration. Thus, in order for selection on social abilities to result in evolutionary changes in brain morphology, there must have been genetic correlations within modern humans between brain anatomy and social ability. To assess this possibility, associations between localized brain anatomy and several behavioral measures related to social facility were determined on a sample of 36 female sibling pairs (72 subjects total). Voxel‐based morphometric methods were used to quantify brain morphology in MRI scans, and self‐reported degrees of social interaction/engagement were used as a proxy for sociality. A within‐family analysis was used to control for possible confounding variables, such as socioeconomic status. Our results show both positive and negative associations distributed across various regions of the brain. There are positive correlations in the splenium of the corpus callosum, the anteromedial prefrontal cortex, and the left cerebellum. Negative correlations are seen in areas of the orbital frontal and anterior cingulate, though they are modest.Grant Funding Source: Indiana University
Stimulation of the BLM‐hDNA2 pathway of DNA double‐strand break end resection by TopoIIIα/RMI1/RMI2
Authors: Daley James Matthew , Xue Xiaoyu , Chiba Tamara , Sung Patrick 
Published: June 2021

Homologous recombination (HR) is an important mechanism by which highly toxic DNA double‐strand breaks (DSBs) are accurately repaired. HR begins with nucleolytic resection of the 5′ ends of the DSB, yielding long single‐stranded 3′ ssDNA tails. Multiple partially redundant pathways together carry out this process. Resection appears to be initiated by the DSB end‐binding Mre11‐Rad50‐Nbs1 complex together with CtIP. These proteins catalyze limited resection near the break site, which is followed by long‐range resection via two redundant pathways. In the first, the BLM helicase unwinds the DNA duplex to generate ssDNA strands, followed by cleavage of the 5′ strand by the nuclease DNA2. The second pathway is catalyzed by EXO1, an exonuclease also involved in DNA mismatch repair and processing of damaged or stalled DNA replication forks.To delineate the mechanism of DNA end resection in human cells, we have reconstituted the resection system using highly purified human proteins. Our initial efforts have focused on characterizing the role of Topo IIIα/RMI1/2 (TR) in resection. These proteins form a complex with BLM which performs double Holliday junction dissolution. Topo IIIα is a type I topoisomerase, and the RMI proteins are OB‐fold containing proteins thought to play a structural and stimulatory role in the complex. We have found that TR stimulates resection by BLM/DNA2, but not EXO1. TR stimulates unwinding of double‐stranded DNA by BLM in a manner that is independent of the topoisomerase activity of Topo IIIα. Topo IIIα also promotes 5′ – 3′ resection by preferentially inhibiting the 3′ flap endonuclease activity of DNA2 relative to its 5′ flap endonuclease activity, similar to a previously described role of RPA in this pathway. Atomic force microscopy has revealed that Topo IIIα localizes to the ends of DSBs. These data suggest that TR stimulates resection by recruiting BLM to the break ends and modifying the nuclease activity of DNA2.
SUMO‐binding sites in Nrf2
Authors: Walters Treniqka , Arinze Ifeanyi J 
Published: June 2021

The transcription factor Nrf2 influences transcription by binding to the antioxidant response element(s) (AREs) in target gene promoters, enabling oxidatively stressed cells to mount a response to oxidative stress in order to restore redox homeostasis. Post‐translational modifications (PTMs) that mediate release of Nrf2 from its inhibitory protein Keap1 have been extensively studied but PTMs that impact its biology after this release are just beginning to emerge. In this regard, only phosphorylation and acetylation have been previously reported. We recently found that Nrf2 can also be sumoylated. Here, we used three SUMO site‐predicting algorithms (SeeSUMO, SUMOsp and SUMOplot) to identify putative SUMO‐binding sites in Nrf2. Of the eight high probability sites identified by these algorithms, we found, using site‐directed mutagenesis and Co‐IP assay, that K525 is a SUMO‐targeted site. This site binds SUMO‐2/3. The impact of sumoylation on the transactivation potential and degradation of Nrf2 are shown here.Supported by NIH grants SC1CA143985 and 5T32 GM07628–34.
Chorangiosis in Placental Malaria
Authors: McMichael Ashley B , Moore Julie M. , Burton Samantha , Okafor Uzoma 
Published: June 2021

Chorangiosis is a placental change that could result in fetal, maternal, and placental disorders, and has been found to be correlated with high fetal morbidity and mortality. In this study, we investigate the possible correlation between chorangiosis and Plasmodium falciparium induced malaria in pregnant women.Eight placentas were chosen from malaria‐infected Kenyan women. The placental tissues were cut into three sections, fixed, paraffin‐embedded, sectioned and stained. Images from each section were examined to count villi (placental structures housing the fetal blood circulation) and the number of blood vessels (vascular channels) in each.Chorangiosis was diagnosed in those specimens in which each of the three sections have, on average, ≥10 vascular channels in each villus. Although the assessments are not complete, these preliminary results suggest that whereas uninfected placentas are negative for chorangiosis, placental malaria appears to be associated with an increased risk for chorangiosis.The Plasmodium falciparium induced malaria interactions with maternal, placental, and fetal factors, posed an increased oxidative stress which may possibly contribute to this arising pathologic change
Modification of enzymes by protein folding memory
Authors: Satomura Atsushi , Nagayama Mitsuru , Miura Natsuko , Kuroda Kouichi , Ueda Mitsuyoshi 
Published: June 2021

Propeptides, which are N‐terminal or C‐terminal domain of most proteases and lipases, are cleaved off in the protein maturation steps. Some propeptides are known to function as an intramolecular chaperone to facilitate the folding of their active region. Protein folding memory means a phenomenon in which a mutated propeptide alters the conformation of the enzymatically active region without mutations in the coding region and thereby the activity and thermal stability are altered. However, there are few examples showing the modification of enzymes by protein folding memory.In this study, we attempted to modify carboxypeptidase Y (CPY) by introducing mutations into its propeptide. CPY with the mutated propeptide showed the higher activity and thermal stability than that with wild type propeptide [1]. This result indicated that two CPYs with the identical amino acid sequences were folded into different structures by the different propeptides. Furthermore, we recently have investigated protein folding memory using Rhizopus oryzae lipase (ROL) as the second model. ROL whose propeptide was replaced by the propeptide of ROL‐related lipase showed the higher activity than wild type ROL. Then, the mechanism causing the higher activity was investigated.
Identifying the Mechanism of Reduced Flavin Transfer in Alkanesulfonate Monooxygenase System
Authors: Dayal Paritosh Vijay , Singh Harsimran , Busenlehner Laura , Ellis Holly 
Published: June 2021

The two‐component alkanesulfonate monooxygenase system from bacteria are involved in the acquisition of sulfonates during sulfurlimiting conditions. In this two‐component system the FMN reductase (SsuE) provides reduced flavin to the monooxygenase enzyme (SsuD). The monooxygenase enzyme (SsuD) catalyzes the oxygenolytic cleavage of the carbon‐sulfur bond of alkanesulfonates, leading to the formation of the corresponding aldehyde and sulfite product.The transfer of reduced flavin from SsuE to SsuD may involve either a channeling or dissociative mechanism. Prior studies have identified stable protein‐protein interactions between SsuE and SsuD supporting a channeling mechanism for flavin transfer. The SsuD enzyme belongs to the bacterial luciferase family that includes bacterial luciferase and LadA. Members of this family have a characteristic TIM‐barrel conformation with several insertion regions. The mobile loop contained on the insertion region was shown to be involved in stabilizing loop closure to protect reaction flavin intermediates, but the role of this region in flavin transfer has not been evaluated. HDX‐MS studies were conducted to identify potential interaction sites on each enzyme. The SsuD protected sites were located on the mobile loop region, while the protected sites on SsuE were near the putative active site region. There are noticeable charged and polar residues in these regions, which may play a role in the formation of a transient stable‐structure. Variants of these polar regions were generated to evaluate protein‐protein interactions and flavin transfer were altered. The interaction sites on SsuE and SsuD have the potential to act as a dynamic region which enables the transfer of reduced flavin between the two proteins.