bluuebunny/crossref_metadata_2025_split huggingface dataset:
Renal Response to Dietary Salt in High Sodium Lithium Countertransport (SLC) Baboons
Authors: Cox Laura A , Glenn Jeremy , Rainwater David L , Haywood Joseph R , Shade Robert E 
Published: June 2021

Aim: To identify genes and pathways that regulate SLC activity, a marker for essential hypertension, we challenged normal (N) and high (H) SLC baboons with a high salt (HS) diet and compared renal transcriptome profiles.Study design: NSLC (256 ± 9) and HSLC (426 ± 17) baboons (n = 5/group) were fed a low salt diet (20 mmol/day NaCl) for 8 weeks then fed a HS diet (150 mmol/day NaCl) for 6 weeks. Kidney biopsy transcriptome data from each diet were used for pairwise, cluster and pathway analyses.Results: Analysis of HSLC vs NSLC baboons on HS showed differential expression of 8.2% of expressed genes with 148 genes up‐ and 817 genes down‐regulated [including 10 solute carrier family genes]. Eight KEGG pathways were up‐ and 32 KEGG pathways were down‐regulated including oxidative phosphorylation. Cluster analysis of both SLC groups on both diets revealed 5 clusters. One cluster included 396 genes that were salt responsive in NSLC but not HSLC baboons and included protein kinase C, central to calcium‐, PPAR‐, Wnt‐, MAPK‐, and VEGF‐signaling and NADH dehydrogenase, central to oxidative phosphorylation.Conclusions: Baboon kidney showed salt responsiveness in NSLC baboons for signaling pathways central to sensing stress and nutrients; whereas they were down‐regulated or unchanged in HSLC baboons. This suggests that the HSLC blood pressure phenotype is associated with a lack of response to dietary salt for numerous molecular pathways.
High NaCl activates c‐Abl kinase, phosphorylating TonEBP/OREBP on Y143, which contributes to its increased nuclear localization
Authors: Gallazzini Morgan , Villers Courtney L , Burg Maurice B , Ferraris Joan D 
Published: June 2021

High NaCl activates TonEBP/OREBP (tonicity‐responsive enhancer binding protein/osmotic response element binding protein), resulting in increased transcription of osmoprotective genes. The activation includes nuclear localization of TonEBP/OREBP. An Auxiliary Export Domain (AED) within amino acids 132‐156 of TonEBP/OREBP is involved in its subcellular localization (Tong, JBC 2006). We find that in HEK293 cells: 1) High NaCl increases phosphorylation of Y143. 2) Mutation of Y143 to alanine, which prevents its phosphorylation, reduces nuclear localization of TonEBP/OREBP. 3) Y143 is a consensus c‐Abl phosphorylation site and high NaCl increases c‐Abl kinase activity. 4) c‐Abl phosphorylates Y143 in vitro. 5) c‐Abl coimmunoprecipitates with TonEBP/OREBP, indicating that the proteins are associated. 6) Dominant negative (kinase dead) c‐Abl decreases high NaCl‐induced nuclear localization of TonEBP/OREBP. We conclude that high NaCl increases phosphorylation of TonEBP/OREBP on Y143, catalyzed by c‐Abl kinase, which contributes to increased nuclear localization of TonEBP/OREBP.This research was supported by the Intramural Research Program of NHLBI.
Alterations in renal sodium and acid‐base transport in H,K‐ATPase null mice
Authors: Greenlee Megan , Lynch Jeanette , Rudin Alicia , Wingo Charles 
Published: June 2021

The kidney expresses two H,K‐ATPase isoforms in the collecting duct, HKα1 or HKα2, that function to transport potassium (K) in exchange for protons, particularly in states of K depletion. However, loss of either HKα1 or HKα2 H,K‐ATPase isoforms did not significantly effect either urinary K excretion or systemic acid‐base balance in mice (Spicer et al. J Biol Chem. 2000 275(28); Meneton et al. J Clin Invest. 1998 101(3)). Because another isoform is present in these single knockout animals, we hypothesized that the H,K‐ATPases compensated for each other. To test this hypothesis, the effect of dietary K depletion on renal electrolyte and acid‐base handling was evaluated in double‐knockout mice lacking both HKα1 or HKα2 (HKα1,2−/‐). Surprisingly, HKα1,2−/− mice efficiently conserved urinary K. However, the HKα1,2−/− mice excreted significantly more urinary titratable acid and ammonium, sodium (Na) and chloride (Cl) with no apparent change in blood Na, Cl, pH, or HCO3. With K depletion, HKα1,2−/− mice retained more urinary Na than wild type mice. The evidence suggests that renal H,K‐ATPases may not play an essential role in net renal K conservation. Instead, the pumps may participate directly or indirectly in both Na and acid‐base transport by the kidney.These studies were supported by an NIH grant (RO1‐DK‐049750).
A Simple and Rapid Method for Collecting Cerebrospinal Fluid from Rat
Authors: Liang Xiaojuan , Zhao Tuocheng , Liu Zhengshang , Wang Yehong , Shao Qiming 
Published: June 2021

The goal of this study was to establish a simple, reliable and efficient method for the collection of cerebrospinal fluid (CSF) from rat. Our new technique can easily obtain 150‐200 uL of blood free CSF from rat in less than 2 minutes.MethodUnder anesthesia, rat was flexed downward of the head at approximately 45 degree. A small incision was made in the skin. Overlying the occipital bone, the underlying tissue was prepared in such a way that the atlanto‐occipital membrane in between the occipital bone and the upper cervical vertebra was exposed. The remaining tissue above the atlanto‐occipital membrane was cut by scalp until the atlanto‐occipital membrane is clearly visible. A butterfly needle connected with 1 ml of syringe was used. When collecting CSF, the needle was directly punctured into the cisterna magna, and the non‐contaminated sample was drawn into the syringe until blood appears. We use hemostat to clamp the silicon tubing when the CSF becomes bloody. The tubing is cut with a pair of scissors from the clear part to avoid blood contamination. Then the clear CSF is transferred into eppendorf tubes through an insulin needle.ResultsThis technique had a greater than 95% success of CSF collection. Non‐contaminated 100‐250 µl of CSF can routinely be obtained per rat.In conclusionThis technique has proved to work well in experimental rat. The method is convenient, efficient and provides significant time saving.
Microglial activation during HSV‐1 infection is increased by vitamin E deficiency
Authors: Sheridan Patricia Ann , Beck Melinda A 
Published: June 2021

Previous studies from our laboratory have shown that dietary a‐tocopherol (VE) is critical to regulating the cytokine and chemokine response in the brain to herpes simplex virus (HSV) infection. Microglial cells have been identified as a source of pro‐inflammatory cytokine production during HSV‐1 infection in both humans and mice. During HSV‐1 infection, microglia from BALB/c mice produce a vigorous, but not protective response to HSV‐1. In VE deficient (VE‐D) mice, the pro‐inflammatory response was even more robust than in the VE adequate (VE‐A) mice. In this study, we determined that VE‐D mice have increased proliferation and activation of microglia and increased numbers of infiltrating macrophage following HSV‐1 infection compared to VE‐A mice. Administration of U‐83836E, a lazaroid compound that is a potent inhibitor of membrane lipid peroxidation with anti‐oxidant properties similar to VE, alters the response of microglia in both VE‐A and VE‐D mice infected with HSV‐1. These data suggest that oxidative stress during HSV‐1 infection alters microglial responses and that VE deficiency acts synergistically to amplify this response.Support: P30ES10126 and DK56350.
Effect of vitamin D supplementation on calcium absorption and retention in adolescent girls
Authors: Park Clara Yongjoo , Hill Kathleen M , Elble Ann E , Martin Berdine R , Peacock Munro , McCabe George P , Weaver Connie M 
Published: June 2021

In adolescents, cross‐sectional studies show either no or negative relationship between vitamin D status and calcium absorption. Through a crossover‐design metabolic balance study, we investigated the effect of vitamin D supplementation on calcium absorption and retention in adolescent girls (mean serum 25(OH)D: 19.83 ng/ml). Sixteen girls age 11‐14 yrs consumed a controlled diet (providing 400 IU vitamin D and 1136 mg Ca/d) for two 3‐week metabolic balance periods separated by a 1‐week washout period. Sunlight exposure was minimized by sunscreen with a sun protection factor = 15. After the first metabolic balance period, subjects received 1000 IU vitamin D3/d supplementation for 4 weeks. Calcium absorption was measured each metabolic balance period using a stable calcium isotope method and indirectly through a 5‐hr PTH suppression profile. All urine and fecal samples were collected and analyzed to measure calcium retention. Statistical analysis was done by repeated measures ANOVA. Vitamin D supplementation resulted in a mean increase in serum 25(OH)D of 4.65 ng/ml (p=0.0007), but it had no effect on serum fasting 1,25(OH)2D (p=0.72), calcium absorption (p=0.33), PTH suppression (p=0.92), or calcium retention (p=0.10). Vitamin D supplementation at 1000 IU/d did not affect calcium homeostasis in pubertal girls with vitamin D status levels considered suboptimal in adults.Grant Funding SourceDelavau, LLC
Age‐dependent liver repopulation by transplanted hepatocytes
Authors: Stock Peggy , Ebensing Sabine , Hempel Madlen , Bielohuby Maximilian , Bidlingmaier Martin , Christ Bruno 
Published: June 2021

The low liver repopulation efficacy of transplanted hepatocytes is probably due to their poor proliferative capacity linked to the age of the liver donors. The age‐dependent proliferative potential of wild type F344 rat hepatocytes was investigated after transplantation into old and young CD26‐deficient F344 rat host livers. Repopulation rates were determined by flow cytometry and assay of CD26 enzyme activity.Hepatocytes isolated from either young or old donor rats formed small and rare clusters of donor‐derived hepatocytes in senescent host livers. However, both hepatocytes from juvenile and from senescent donor livers transplanted into juvenile host livers developed cell clusters significantly larger and more frequently as compared with senescent host livers. Repopulation of juvenile host livers by old or young hepatocytes amounted to 20 % as compared 2 % in senescent hosts. No functional difference between transplanted juvenile and senescent hepatocytes was observed in the host liver tissue in terms of glycogen storage. As compared to senescent host animals, serum levels of IGF1 were significantly higher in juvenile rats. Thus, in rats, the age of the recipient liver seems to be critical for the efficient repopulation by transplanted hepatocytes involving regulation along the growth hormone‐IGF1‐axis.
Single‐molecule analysis of transcription
Authors: Ebright Richard H. , Weiss Shimon , Chakraborty Anirban , Wang Dongye , Korlann You , Kapanidis Achillefs , Margeat Emmanuel 
Published: June 2021

We are using single‐molecule fluorescence resonance energy transfer to define fundamental aspects of transcription initiation, elongation, and termination.In published work, we have shown that initial transcription proceeds through a "scrunching'' mechanism, in which RNA polymerase (RNAP) remains fixed on promoter DNA and pulls downstream DNA past its active center. We have shown further that putative alternative mechanisms for RNAP‐active‐center translocation in initial transcription, involving "transient excursions" of RNAP or "inchworming" of RNAP, do not occur. The results support a model in which a stressed intermediate, with DNA‐unwinding stress and DNA‐compaction stress, is formed during initial transcription, and in which accumulated stress is used to drive breakage of RNAP‐promoter interactions during promoter escape.In unpublished work, we are assessing opening and closing of the RNAP active‐center‐cleft, movements of modules of sigma relative to RNAP in transcription initiation, movements of modules of the RNAP active center in transcription elongation, and movements of RNAP relative to DNA in transcription termination. In further unpublished work, carried out in support of these studies, we have developed reagents and procedures that permit incorporation of a fluorescent probe at any position of interest within a transcription complex.
Crystallographic studies of ribosomal frameshifting
Authors: Selmer Maria , Chen Yang 
Published: June 2021

A recent 2.8 Åcrystal structure of the 70S ribosome from Thermus thermophilus shows many details of how the ribosome interacts with its mRNA and tRNA substrates (1). During translation, specific tRNA‐mRNA combinations can cause frameshifting, deviations from the normal three‐base reading frame. The aim of this work is to gain structural and functional understanding of why these deviations occur and how the ribosome in the normal case prevents them from occurring.Mutated frameshift suppressor tRNAs containing eight‐base anticodon loops can cause a +1 frameshift through decoding of a four‐base codon. The crystal structures of such ASLs (anticodon stem‐loops) bound to their cognate four‐base mRNA codons in the context of the ribosomal A site showed that three bases of the extended anticodon covered four bases of the mRNA (2).When the tRNA balance is altered, tRNA3Ser, that normally decodes AGU and AGC, can cause ‐1 frameshifting at a GCA alanine codon. Nitrocellulose filter binding studies indicate that this occurs through a doublet decoding mechanism.The current status of our crystallographic studies of frameshift‐related ribosomal complexes will be presented.1. Selmer, M et al., Science 313(5795):1935‐1942 (2006)2. Dunham, C.M. et al., RNA 13(6):817‐23 (2007)
Effect of a pecan meal on postprandial plasma concentrations of hydro‐ and lipophilic oxygen radical absorbance capacity (ORAC) in human volunteers
Authors: Hudthagosol Chatrapa , Hasso‐Haddad Ella , Rajaram Sujatha , Oda Keiji , Sabaté Joan 
Published: June 2021

ObjectivePecans (Carya illinoinensis) are rich in phenolic substances which may contribute to the body's antioxidant defenses. The objective of this study was to determine the effect of pecans on postprandial antioxidant responses.MethodsTest meals containing 100g whole pecans, 100g ground pecans, or an energy‐equivalent amount of refined olive oil as control were administered in a randomized crossover design to 16 healthy volunteers with a 1‐week washout. Plasma was sampled at baseline and at intervals up to 24 hours after consumption of the test meal. Oxygen radical absorbance capacity (ORAC) assays were carried out using the procedure described by Prior et al. (2003). Mixed model analyses of data were performed using SAS version 9.2.ResultsLeast square means±SE for the 5‐hour area under the curve (AUC) after the whole pecan, ground pecan and control meals were 80.0±3, 77.2±3.0, 72.8±8 mmol·h/L trolox equivalents for hydrophilic; and 415±16, 412±16, 374±16 mmol·h/L trolox equivalents for lipophilic components, respectively. Both hydrophilic and lipophilic ORAC values increased about 10% (p<0.001) following the whole pecan test meals.ConclusionAlthough modest, the increases in plasma antioxidant capacity following pecan consumption may be physiologically important and further study is needed.Funding: National Pecan Shellers Association
Pecan‐enriched meal inhibits postprandial LDL oxidation in healthy subjects
Authors: Mccarthy Katie , Gaban‐Chong Natasha , Hudthagosol Chatrapa , Oda Keiji , Sabaté Joan , Hasso‐Haddad Ella 
Published: June 2021

ObjectivePecans (Carya illinoinensis) are a source of tocopherols and phenolics which may confer health benefits. The objective of this study was to test the effect of pecans on postprandial concentrations of circulating phenolic components and oxidized‐LDL (ox‐LDL) responses.MethodsPlasma levels of ox‐LDL and polyphenols were measured in 16 healthy subjects after consumption of test meals with either 100g of whole pecans, 100g of ground pecans or an energy‐equivalent amount of refined olive oil as control in a randomized cross‐over design at 1‐week intervals. Phenolic concentrations were determined by the Folin‐Ciocalteau reagent and oxidized‐LDL by ELISA (Alpco Diagnostics, Salem, NH).ResultsThe change in log(ox‐LDL) over 24 hours was examined using a mixed model statistical approach with repeated measures over time. A significant decrease in log ox‐LDL was found at 2 hours (‐29.6%, p=0.04) and 3 hours (‐33.3%, p<0.02); however, levels at 1, 5, 8 or 24 hours were not different from baseline. A 21% increase (p<0.05) in phenolic 5‐hour AUC was observed after the ground pecan compared to control meal (LSMƒpSE 8.25ƒp0.9 vs 6.91ƒp0.9 mmol·h/L gallic equivalents, respectively).ConclusionPecan consumption may increase postprandial circulating phenolic compounds and protect LDL cholesterol from oxidation.FundingNational Pecan Shellers Association
Acyl‐CoA Synthetase‐isoform 1 (ACSL1) is essential for FA oxidation in adipose tissue: lessons from adipose‐specific knockout of ACSL1
Authors: Ellis Jessica Mary , Wu Pei‐Chi , Li Lei , Coleman Rosalind Ann 
Published: June 2021

Long chain acyl‐CoA synthetase (ACSL) catalyses the conversion of fatty acids into their acyl‐CoA derivatives. ACSL1, one of five ACSL isoforms, is highly expressed in white and brown adipose tissue where it was thought to be important for triacylglycerol formation. To investigate the role of ACSL1 in adipose tissue we created an adipose‐specific knockout of ACSL1, the ACSL1A‐/− mouse. Although we expected these mice to have a reduced ability to store fatty acids as triacylglycerol in adipose, compared to control mice (ACSL1flox/flox) when fed a low‐fat diet, subcutaneous and visceral fat depot mass was 30% higher in ACSL1A‐/− mice, and when fed a diet containing 45% kcal fat, weight gain was similar. In mature adipocytes isolated from ACSL1A‐/− mice, the rate of fatty acid oxidation was 50% lower, suggesting a role for ACSL1 in FA oxidation rather than TAG synthesis. ACSL1A‐/− mice were cold intolerant with body temperature dropping below 30°C within 2‐5 h in a 4°C environment. ACSL1A‐/− mice had reduced oxygen consumption in response to adrenergic stimuli but had intact cold‐stimulated transcriptional expression of PGC‐1α and UCP1 in brown adipose tissue, showing that adrenergic signaling was intact. The reduced FA oxidation in white adipocytes, together with the cold intolerance of the ACSL1A‐/− mice, strongly indicates that ACSL1 activates fatty acids destined for oxidation.Grant Funding SourceAHA‐Pre‐doctoral Fellowship Mid‐Atlantic Affiliate
Regulation of vascular calcification by endogenous ATP release coupled to extracellular pyrophosphate accumulation: Modulation by cAMP signaling
Authors: Prosdocimo Domenick Anthony , Dubyak George R. 
Published: June 2021

Extracellular pyrophosphate (ePPi) inhibits vascular smooth muscle cell (VSMC) calcification and we have found that extracellular ATP (eATP) constitutively released from VSMC is coupled to ePPi generation via the NPP1/PC‐1 ecto‐ATPase. Recent studies have indicated that cAMP/PKA‐induced calcification modulates ePPi homeostasis. Thus, we tested whether such cAMP signaling pathways also perturb ePPi accumulation via attenuation of eATP release and/or the NPP1‐mediated hydrolysis of eATP. We report that forskolin (Fsk)‐induced activation of cAMP/PKA in primary rat VSMC suppresses eATP release and coupled ePPi accumulation in the absence of decreased NPP1 activity. This Fsk‐induced attenuation of endogenous eATP release and ePPi potentiates phosphate (Pi)‐induced VSMC calcification, an effect rescued by exogenously added ATP. These data provide direct support for a model wherein constitutive ATP release is efficiently coupled to PPi generation (via NPP1) to inhibit aberrant mineralization in VSMC.(Supported by P01‐HL18708, RO1‐GM36387, and T32‐HL07887).
TGF‐β superfamily type‐II receptor regulation of telomerase and telomeres in human breast cancer cells
Authors: Nicholls Craig Daniel , Cassar Lucy , Li He , Liu Jun‐Ping 
Published: June 2021

Transforming growth factor‐beta (TGF‐β) plays an important role in regulating telomerase activity in cancer cells. Signalling by TGF‐β superfamily ligands is initiated by ligand binding to one of four transmembrane receptor kinases and subsequent phosphorylation of target proteins, resulting in intracellular signalling cascades. Whereas the downstream target protein Smad3 represses the gene coding for telomerase reverse transcriptase (TERT), the roles of the specific receptors of the TGF‐β family in mediating regulation of telomerase activity remain to be established. Many recent studies indicate a key role for the TGF‐β family receptors in cancer cell proliferation, with truncating mutations detected in many cancers ‐ particularly those of breast, colorectal and prostate origin. Such mutations inactivate the kinase ability of these receptors and abolish downstream signalling. This work focuses on the effect of dominant‐negative (DN) type‐II receptors on telomerase and telomeres in breast cancer cells.Human breast cancer MCF‐7 cells were transfected with plasmid constructs expressing truncated type‐II receptors fused to GFP. After approximately 2.5 months stably transfected cells were analysed for telomerase activity, telomere length, cell proliferation and senescence markers. Cells expressing DN‐BMPRII exhibited increased telomerase activity coupled with increased cell proliferation relative to control. Conversely, cells expressing DN‐ACVRIIA/B or DN‐TGFβRII all had decreased telomerase activity, reduced telomere length and an increase in cellular senescence. Taken together these results indicate that BMPRII signalling mediates inhibition of telomerase activity and cell proliferation in MCF7 breast cancer cells, whereas TGFβRII and ACTRIIA/B signalling may be required to sustain telomerase activity and cell proliferation.
Analysis of archaeal histone interactions from M. fervidus.
Authors: Stencel Katherine Ann , Tims Hannah S. 
Published: June 2021

Archaea are prokaryotes with cellular characteristics of eukaryotes. Homologues of eukaryotic histones are found in some archaea, however, the structural and functional characteristics of archaeal nucleosomes are not well understood. Archaea can have 0‐6 histones, which are able to form hetero/ homodimers. Histones from the archaea, Methanothermus fervidus (HMfA, HMfB) were expressed and purified from E. coli plasmids containing clones of the histones (gift of Kathleen Sandman, The Ohio State University). Cloned archaeal high affinity DNA sequences were purified from E. coli to be used to assemble nucleosomes. The histones were tagged with fluorescent dyes to be used in Fluorescence resonance energy transfer (FRET) experiments to study histone‐histone and histone‐DNA interactions. To allow specific placement of the dyes, the histones were mutated to introduce cystine residues as attachment sites. Kathleen Sandman (OSU) provided mutated HMfB. HMfA will be mutated with a QuickChange mutagenesis kit (Stratagene) for hetero‐histone complex investigation.This work was supported by a grant to The College of Wooster from the Howard Hughes Medical Institute through the Undergraduate Science Education Program.