bluuebunny/crossref_metadata_2025_split huggingface dataset:
Increased CaM kinase II‐mediated phosphorylation of ampa receptors precedes status epilpeticus
Authors: Schafer Johanna Marlies , Churn Severn , Kurz Johnathon , Low Brian 
Published: June 2021

This study was conducted to analyze the change in calcium/calmodulin‐dependent kinase II (CaMK II)‐mediated phosphorylation of AMPA receptors at times points throughout the duration of stats epileptics (SE). The GluR1 subunit of the AMPA receptor is phosphorylated at ser831 by CaMK II; the progression of seizure activity into the continuous seizures of status epilepticus may be due to potentiation of excitatory postsynaptic neurotransmission by AMPA‐receptor‐mediated currents.MethodsSE was induced by a pilocarpine injection. At three time‐points of discrete seizures preceding SE, 20 and 40 minutes after the onset of SE, and 24 hours post‐SE, cortical and hippocampal brain regions were isolated into homogenization buffer and used for biochemical studies. Proteins were resolved by SDS‐PAGE and subjected to western blot analysis. GluR1 phosphorylation was assessed using phosphoGluR1‐specific antibodies and computer‐assisted densitometry.ResultsAll time point proceeding and during SE had over a 150% increase in phosphorylation at ser831compared to the controls. The increase in pGluR1 was observed well into overt SE. Although, the last time point, 24 hours post‐SE, did not demonstrate a statistically significant change in phosphorylation levels.ConclusionsThis data suggests that elevated AMPA‐directed CaMK II activity may increase the functionality of excitatory AMPA receptors prior to and during status epilepticus. At the 24 hour time‐point, GluR1 phosphorylation appeared to return to control levels, suggesting a return of CaMK II activity to normal levels.
Autonomic, cardiovascular and thermoregulatory responses to central neropeptide Y or neuromedin U in rats
Authors: Tanida Mamoru , Nagai Katsuya 
Published: June 2021

Previous studies have demonstrated that neuropeptide Y (NPY) or neuromedin U (NMU) affects cardiovascular functions such as blood pressure (BP) or heart rate (HR) in rats. Here, we examined the effects of the central injection of various doses of NPY or NMU on renal sympathetic nerve activity (RSNA) and BP in urethane‐anesthetized rats. Central injection of NMU elevated RSNA, BP and HR in a dose‐dependent manner, while NPY injection reduced RSNA, BP and HR RSNA, BP and HR.In addition, central injection of NMU suppressed gastric vagal nerve activity (GVNA) and activated brown adipose tissue sympathetic nerve activity (BAT‐SNA) of anesthetized rats, and elevated brown adipose tissue temperature (BAT‐T) of conscious rats. Oppositely, NPY affected autonomic nerves and elevated the GVNA and suppressed BAT‐SNA and BAT‐T.Moreover, neither pretreatment of thioperamide, an antagonist of histaminergic H3‐receptor, or of diphenhydramine, an antagonist of histaminergic H1‐receptor, abolished increasing effects of NMU on RSNA, BP and HR However, pretreatment of thioperamide eliminated suppressive responses of RSNA, BP and HR to NPY injection. Thus, these lines of evidence suggest that NMU or NPY affects neural activities of autonomic nerves containing RSNA, GVNA or BAT‐SNA, and BP by mediating central mechanism, and possible role of histaminergic neurotransmittion in autonomic controls by NPY.
Multiple red cell volumes (RCV) can be independently determined in sheep in vivo using red cells (RBCs) labeled at 4 biotin densities
Authors: Mock Donald M , Matthews Nell I , Strauss Ronald G , Burmeister Leon F , Schmidt Robert , Widness John A 
Published: June 2021

Here we report our further development and validation of a method for independent, simultaneous measurement of RCV in sheep using flow cytometric enumeration of multiple populations of RBCs labeled at distinct biotin densities.MethodThe density of biotin on the surface of the RBCs was incrementally increased to produce 4 discrete populations of biotinylated RBCs (BioRBCs). BioRBCs and RBCs labeled with 14C‐cyanate were infused into the sheep, and blood samples were drawn at 10 min.ResultsAt biotinylation reagent concentrations < 96 µg/mL RBC, the biotin method reproducibly determined RCV; mean error = 4.2% versus the reference 14C‐cyanate method (n=2 sheep). RCV values agreed among the densities; mean CV= 2% for 4 sheep. For reagent concentrations > 96 µg/mL RBC, BioRBCs were rapidly removed from circulation; this rapid removal caused an overestimate in RCV.ConclusionsBioRBCs at densities low enough to survive in the circulation can be used for simultaneous in vivo measurements of RCV in sheep.SpeculationIn humans, BioRBCs can be used to repeatedly measure RCV in the same individual. This method will be useful in the investigation of the physiology and pathophysiology of the pregnant woman, fetus, and infant because only small sample volumes are required and because the individual is not exposed to radiation. NIH P01 HL046925 and Thrasher Research Foundation 02825‐3.
Seed based systematic discovery of specific transcription factor target genes
Authors: Mrowka Ralf , Blüthgen Nils , Kielbasa Szymon , Persson Pontus Börje , Fähling Michael 
Published: June 2021

Reliable prediction of specific transcription factor target genes is a major challenge in functional genomics. Current sequence‐based methods yield many false predictions due to the short and degenerated DNA‐binding motifs.Here, we describe a new systematic genome‐wide approach, the seed‐distribution‐distance method that searches large scale genome wide expression data for genes that are similarly expressed as known targets. This method is used to identify genes that are likely targets and thereby sequence‐based methods can focus on a subset of genes, giving rise to fewer false positive predictions. We show by cross‐validation that this method is robust in recovering specific target genes. Further, this method identifies genes with typical functions and binding motifs of the seed. The method is illustrated by predicting novel targets of the transcription factor NFkB. Among the new targets is optineurin, which plays a key role in the pathogenesis of acquired blindness caused by adult‐onset primary open‐angle glaucoma. We show experimentally that optineurin as well as other predicted genes are targets of NFkB.We present a robust and reliable method to enhance the genome‐wide prediction of specific transcription factor target genes that exploits the vast expression information available in public databases today. A public web interface for customized searches will be available.
SGK1 and insulin reduce the activity of mammalian electrogenic Na+/Monocarboxylate Transporters (SMCTe/Slc5a8)
Authors: López Adriana , Vázquez Noma , Torres Nimbe , Zandi‐Nejad Kambiz , Mount David B , Gamba Gerardo , Tovar Armando R , Romero Michael F , Plata Consuelo 
Published: June 2021

SMCTe (SLC5A8) transports several monocarboxylates, including short‐chain fatty acids, ketone‐bodies, pyruvate, lactate, and keto‐isocaproic acid (KIC). We found SMCTe mRNA in zebrafish pancreas (in situ hybridization); other groups have demonstrated that SLC5A8 gene silencing is associated with pancreatic cancer. Extracellular KIC stimulates insulin secretion in pancreas, suggesting a potential role for SMCTe. However, the physiological role of SMCTe in pancreas is unknown. Using RT‐PCR with rat SMCTe‐specific primers, we found that SMCTe mRNA is expressed in rat pancreas. Using Western Blot analysis with specific SMCTe antibodies, we also detected SMCTe protein in rat pancreas (~75 kDa). We next tested the effect of insulin on SMCTe function using 22Na+ uptake in Xenopus oocytes injected with human SMCTe (hSMCTe) or co‐injected with hSGK1 cRNA. Specifically, we evaluated transport 22Na+ uptake elicited by 40 U insulin in presence or absence of KIC. Insulin reduced KIC‐mediated 22Na+ uptake transport by ~25% in hSMCTe‐oocytes. Human SGK1 also reduced KIC‐mediated 22Na+ uptake transport by ~25% in hSMCTe‐oocytes. Co‐expression of hSMCTe and hSGK1 in oocytes did not further reduce KIC‐mediated 22Na+ uptake. These results indicate that the signal transduction pathway by which insulin and SKG1 reduce SMCTe transport activity overlaps.CONACYT48709MJ(CP), EY017732(MFR), DK070756(DM), DK64635(GG)
Quantitative trait loci for exercise capacity and response to training in FVB/NJ and C57BL/6J mice
Authors: Massett Michael P , Berk Bradford C 
Published: June 2021

The genetic factors determining the magnitude of the response to exercise training are poorly understood. The aim of this study was to identify quantitative trait loci (QTL) associated with adaptation to exercise training in mice. Mice completed an exercise performance test before and after a 4‐week treadmill running program and changes in exercise capacity, expressed as work (kg‐m), were calculated. The change in work with exercise training was significantly different between inbred C57BL/6J (B6) and FVB/NJ (FVB) mice (0.34±0.12 vs. 1.78±0.17 kg‐m, P<0.05). FVBxB6 F1 mice had an intermediate phenotype (1.21±0.35). In F2 mice (n=188), changes in work ranged from ‐1.67 to +4.55 kg‐m. All F2 mice were genotyped at 20 cM intervals using 103 SNPs and genome scans were performed. Suggestive QTL (P=0.63) for changes in work were found on chromosomes 3, 11, and 14. In addition, significant QTL (P<0.05) were identified for pre‐ and post‐training work. QTL for pre‐training work were located on chromosomes 8 (peak at 60.1 cM, 4.47 LOD), 14 (15.3 cM, 4.16 LOD), and 19 (40.6 cM, 3.68 LOD). QTL for post‐training work were located on chromosomes 3 (72.2 cM, 4.83 LOD) and 14 (21.3 cM, 4.88 LOD). These data indicate that one or more QTL determine exercise capacity and training responses in mice. Furthermore, these data suggest that the genes that determine pre‐training work and training responses may differ.Supported by AHA SDG and HL‐085918 (MPM) and HL‐62826 (BCB).
Role of Phosphodiesterase 1A in Cold‐induced Hypertension and Cardiac Hypertrophy
Authors: Sun Zhongjie , Zhang Zhonge 
Published: June 2021

The calcium/calmodulin‐dependent phosphodiesterase 1A (PDE1A) hydrolyzes the intracellular second messengers cAMP and cGMP. Cold exposure to (6 hr/day) results in hypertension and cardiac hypertrophy. PDE1A expression was up‐regulated in resistance arteries, kidneys and hearts of cold‐exposed rats. We hypothesized that RNAi inhibition of PDE1A would attenuate cold‐induced hypertension (CIH) and cardiac hypertrophy (CICH).We constructed AAV carrying PDE1AshRNA, ControlshRNA, and LacZ driven by a CMV promoter. Four groups received an intravenous injection of AAV.PDE1A‐shRNA, AAV.Control‐shRNA, AAV.LacZ, and PBS, respectively, before exposure to cold (5°C), while 1 group received PBS and was kept at room temperature as a control. BP was increased significantly in all cold‐exposed groups except the group treated with PDE1AshRNA, indicating that PDE1AshRNA prevented CIH. PDE1AshRNA enhanced hypothesive responses to acetylcholine in cold‐exposed rats, indicating improved endothelial dysfunction. The in vivo left ventricle wall thickness was also decreased significantly in the cold‐exposed rats treated with PDE1AshRNA. PDE1A‐shRNA attenuated the cold‐induced increases in heart weight, cardiomyocyte sizes, and vascular wall thickness. PDE1AshRNA increased intracellular cGMP and cAMP levels and decreased VSMC cell proliferation and migration. Thus, PDE1A plays a critical role in the pathogenesis of CIH and CICH.
Folic acid supplementation inhibits homocysteine‐induced superoxide anion production and chemokine expression in the kidney
Authors: Hwang Sunyoung , Sarna Lindsei , Siow Yaw L. , O Karmin 
Published: June 2021

Hyperhomocysteinemia (HHcy), a condition of elevated blood homocysteine (Hcy) levels, is a metabolic disease. Kidney dysfunction is a common risk factor causing HHcy. Recent studies indicate that HHcy also lead to renal injury by inducing oxidative stress and expression of inflammatory markers. Monocyte chemoattractant protein‐1 (MCP‐1) is a potent chemokine that stimulates monocyte/macrophage accumulation in the kidney. Upregulation of this chemokine is associated with inflammatory injury. Although folic acid supplementation can reduce blood Hcy levels, its effect on the kidney is not clear. The aim of this study was to investigate the effect of folic acid on Hcy‐induced superoxide generation and chemokine expression in the kidney. HHcy was induced in Sprague Dawley rats fed a high‐methionine diet. The NADPH oxidase‐mediated superoxide production and MCP‐1 mRNA expression were significantly increased in HHcy rat kidneys. Folic acid supplementation effectively abolished HHcy‐induced oxidative stress by inhibition of NADPH oxidase activation. This, in turn, prevented HHcy‐induced chemokine expression in the kidney. Such a beneficial effect of folic acid is not directly related to Hcy reduction. Our results suggest that folic acid supplementation may offer a renal protective effect by antagonizing oxidative stress‐mediated inflammatory response.(This study was supported by NSERC and CIHR)
Hemodynamic Responses to Prenatal Stress and/or Restraint Stress in Rats
Authors: Chen Fangping , Mullenax Heather , Sharma Puneet , Finkel Mitchell S 
Published: June 2021

We reported that a combination of prenatal stress (PS) and restraint stress (PS+R) resulted in echocardiographic evidence of myocardial dysfunction in rats. We now report hemodynamic measurements in PS, R, or PS+R. PS, R and PS+R blunted baseline systolic and diastolic function under anesthesia. However, no differences were observed in +dp/dt and ‐dp/dt in PS or R in awake state. In contrast, the differences in +dp/dt and ‐dp/dt persisted with the PS+R in the awake state. Attenuated responses to isoproterenol were still apparent in PS, R and PS+R. The p38 MAPK inhibitor, SB 203580, reversed the blunted +dp/dt and ‐dp/dt. These findings support a central role for p38 MAP kinase in stress‐induced reversible myocardial dysfunction.Mean±SE; * p<0.05 ,** p<0.01, control+R vs PS+R; # p<0.01, control vs PS+R
INTERACTION AND REGULATION OF FOCAL ADHESION KINASE BY CARDIAC MYOSIN
Authors: Santos Aline M. , Schechtman Deborah , Marin Talita M. , Franchini Kleber G. 
Published: June 2021

AimFocal Adhesion Kinase (FAK) has been implicated in signaling and hypertrophy to mechanical stress in cardiomyocytes. We investigated whether C‐terminal sarcomeric myosin (C‐MHC) controls FAK quiescence and its function in cardiomyocytes.MethodsFAK/MHC association was detected by pulldown assay. Peptides were rationally designed aligning ligants of C‐MHC with the FAK FERM domain. FERM derived peptide (R1) and control peptide (R2) were conjugated to TAT47‐57 carrier. Neonatal rat ventricular myocytes (NRVMs) were stretched in silicone plates (1 Hz, 10%). FAK distribution was assessed by immunofluorescence. FAK depletion was obtained with siRNA.ResultsPulldown assays showed C‐MHC/FAK physical interaction mediated by FERM domain. FAK autophosphorylation reduced its ability to bind C‐MHC. Stretching NRVMs or treating them with R1 reduced FAK/C‐MHC association in parallel with increasing FAK phosphorylation at Tyr397 (4 fold) and translocation to the nucleus. Treatment with R1 (24hs) induced hypertrophic morphology in NRVMs. These effects were accompanied by activation of AKT/mTOR/S6K pathways. Treatment with rapamycin or depletion of FAK with siRNA abolished the hypertrophy induced by R1.ConclusionOur results indicate that the interaction of FAK with C‐MHC may have a role in the regulation of FAK activity and hypertrophic effects in cardiomyocytes.
Localization of the sural nerve in relationship to calcaneal (Achilles) tendon repair
Authors: Atsas Stavros , Blackmon Joseph A , Campbell Ferrell R , Wells Michael J , Lambert H. Wayne 
Published: June 2021

The sural nerve is a major cutaneous nerve of the lower limb that supplies the posterolateral leg and the lateral margin of the foot. It is at risk of iatrogenic injury even during minimally‐invasive surgical procedures to repair the calcaneal (Achilles) tendon. This cadaveric study investigated the point at which the sural nerve crossed the lateral boundary of the Achilles tendon to enable clinicians to identify the location of the sural nerve within 90% and 95% confidence intervals. In most cases, the sural nerve crossed the lateral border of the Achilles tendon 8‐10 cm along the vertical length of the tendon. Based upon the results of 107 leg dissections, surgeons can approximate the location of the sural nerve with confidence and minimize the damage to this important cutaneous nerve.Grant Funding SourceAAA Student/Postdoctoral Travel Award
An inverse dynamic model of the plantar aponeurosis: the influence of walking speed
Authors: caravaggi paolo , Pataky Todd , Savage Russel , Crompton Robin 
Published: June 2021

An inverse dynamics approach has been used to gain an insight into the mechanical behaviour of the plantar aponeurosis (PA) at different walking speeds. To our knowledge only one study has addressed the dynamic behaviour of the PA with relation to the Achilles tendon force (Erdermir, 2004). The aims of this study were to create a multibody model to quantify PA tension and to examine how PA tension changes with walking speed.Ultrasonography was employed to determine the origin of the PA at the inferior aspect of the calcaneus and the radii of the metatarsal heads for three subjects who volunteered in the study. Commercial software for multibody dynamics analysis (MSC.Adams) was used to build the subject‐specific model geometry and to calculate the elongation trajectories for five segments of the PA based on stance phase kinematics data.The PA was pre‐tensioned during early stance phase in all subjects. The amount of pretensioning and the maximum elongation of the slips of the PA decreased from medial to lateral. Peak PA tension occurred in late stance phase (~1.5 BW) for all walking speeds and was similar in magnitude to cadaver simulation.Preliminary results demonstrate model validity and reveal an interesting relation between PA tension and walking speed. The increase in PA tension with walking speed during early stance may represent a pre‐loading protective mechanism.This study was supported by the ASGBI.
Podosome‐like tubulobulbar complexes internalize intact junctions in the seminiferous epithelium
Authors: Young J'Nelle Sarah , Asis Marc De , Vogl A. Wayne 
Published: June 2021

Tubulobulbar complexes are actin‐rich double‐plasma membrane protrusions with associated vesicles that form at intercellular junctions in the seminiferous epithelium of the mammalian testis. One role that has been proposed for these 'podosome‐like' structures is that they internalize 'intact' intercellular junctions during the translocation of spermatocytes through basal junction complexes between Sertoli cells, and during sperm release from Sertoli cells at the apex of the epithelium. If tubulobulbar complexes internalize junctions, then components of tubulobulbar complexes that contain junction proteins also should be associated with endosomal markers. In this study, we probed apical tubulobular complexes in fixed epithelial fragments of rat and mouse testes for adhesion molecules (alpha‐6 integrin in rat, and nectin 2&3 in mouse) and early endosomal markers (Rab 5 in rat and EEA1 in mouse). The antibody to Rab 5 labeled the distal ends of tubulobulbar complexes that also labeled strongly with the antibody to alpha‐6 integrin. EEA1 surrounded vesicles at the ends of tubulobulbar complexes that also were positive for nectin 2 and nectin 3. These results are consistent with the proposal that tubulobulbar complexes are subcellular machines that internalize intact intercellular junctions in the testes.Grant Funding SourceNSERC
Renshaw cell loss in a transgenic mouse model of amyotrophic lateral sclerosis
Authors: Blanchard Stephane Robert , Al‐Marsoummi Sarmad , Carr Patrick Arthur 
Published: June 2021

The distribution and abundance of immunohistochemically‐identified Renshaw cells was studied in the cervical and thoracic spinal cord of an amyotrophic lateral sclerosis (ALS) mouse model. Transgenic G93A‐SOD1 mice displayed ALS‐like disease onset at 70 to 90 days of age with paresis at 100 to 130 days of age. Gephyrin immunofluorescence was used to identify putative Renshaw cells in tissue from mice at 45, 70 and 112 days of age. Preliminary results suggest that in this model of ALS, functional deficits are preceded and accompanied by a profound loss of gephyrin‐labeled putative Renshaw cells.In sections of cervical spinal cord, means counts per ventral horn were: at 45 days ALS=0.70 and control=2.60; at 70 days ALS=0.90 and control=2.12; and at 112 days ALS=1.00 and control=2.61. In sections of thoracic spinal cord, means counts per ventral horn were: at 45 days ALS=0.73 and control=1.07; at 70 days ALS=0.73 and control=0.98; and at 112 days ALS=0.2 and control=0.96.Differences were significant (p<0.05; Mann‐Whitney Rank Sum test) for all ages and spinal cord levels. A significant decrease in the number of Renshaw cells prior to the onset of the disease suggests that, in this model, the loss of motor‐related interneurons precedes clinical progression of the disease. Supported by NIH 5R01HL075034‐05.
New parameters for analysis of changes microglial morphology using stereology and histomorphometry
Authors: Lyck Lise , Bulavina Larissa , Finsen Bente 
Published: June 2021

New parameters for analysis of changes microglial morphology using stereology and histomorphometryIn histological evaluation of experimental and pathological specimens, the degree of microglial activation is often evaluated on the basis of morphological features of the cells including the size and shape of the cells, the number and length of cell processes, as well as by increased expression of markers such as CD11b, CD45 (LCA) and Iba‐1. From stereological studies it is known that microglial activation is followed by proliferation of microglial cells and change in the morphology of the cells.To extend the list of morphological parameters that can be measured quantitatively for comparative studies, we combined digital image analysis and stereological methods for analysis of the morphology of microglia labeled by Iba‐1. In the molecular layer of fascia dentata of the hippocampus from 6 male C57Bl6‐mice the total number of microglial cells was 16 906 cells, the mean cell size was 151.3 µm3, and the average length of cell processes was 80.0 µm/cell. We found microglial cell bodies were ovoid in shape, as judged by the ratio of the shortest and longest diameter (ratio = 0.61) and that on average 5.65 cell processes were extending at the equatorial plane of the cell.