bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abnormal methyl group metabolism and epigenetic regulation in the Zucker (type 2) diabetic fatty rat
Authors: Williams Kelly T. , Schalinske Kevin L. 
Published: June 2021

Methyl group metabolism and DNA methylation have been shown to be altered in a streptozotocin‐induced model of type 1 diabetes. The Zucker diabetic fatty (ZDF) rat exhibits similar perturbations of methyl group metabolism, but DNA methylation status and the expression of epigenetic regulatory proteins have not been characterized in this model of type 2 diabetes. Because epigenetic regulation could be linked to secondary complications associated with type 2 diabetes, we chose to examine methyl group metabolism, including DNA methylation, in the liver and pancreas, as well as the heart and kidney. At 12 wk of age, 6 ZDF and 6 lean rats were sacrificed for blood and tissue analysis. As expected, ZDF rats were diabetic (2X increase in glucose and insulin) and exhibited marked hypohomocysteinemia. Glycine N‐methyltransferase (GNMT), a regulator of transmethylation, was divergently regulated in different tissues. In ZDF rats, hepatic GNMT activity and abundance were increased, whereas pancreatic activity was decreased. No change was noted in renal GNMT activity and abundance, or cardiac GNMT abundance, despite a lack of activity. In contrast to type 1 diabetes, hepatic DNA was hypermethylated in ZDF rats. Mechanistically, it appears that expression of epigenetic regulatory proteins (i.e. DNA methyltransferases and methyl CpG binding proteins) was abnormal in diabetic animals as well. (Support: Amer. Heart Assoc.)Grant Funding SourceAmerican Heart Association
Longer‐term Effects of a Low Glycemic Index Diet on Glycemic Control in Type 2 Diabetes
Authors: Kendall Cyril , Esfahani Amin , Parker Tina , Banach Monica , Mitchell Sandra , Jenkins David 
Published: June 2021

BackgroundNut consumption, including peanuts, has been associated with a reduced risk of coronary heart disease (CHD). More recently, interest has grown in the potential value of including nuts in diets of individuals with diabetes.ObjectiveTo determine if tree nuts and peanuts improve glycemic control in non‐insulin dependent diabetes, as assessed by HbA1c and to assess whether these outcomes relate to improvements in CHD risk (serum lipids, blood pressure and oxidative stress and inflammatory biomarkers).MethodsApproximately 120 NIDDM subjects (BMI ≤32kg/m2) treated with oral hypoglycemic agents (HbA1c 6.5‐8.0%) were recruited to a 3 month parallel design study. Subjects were randomized to one of three treatments: 1) Test (Full Dose Nut Diet): Raw nuts were added as supplements to the subject's usual diet based on required energy intake (≥2,400kcal/d received 100g/d nuts, ≈600kcal; 1,600‐2,400kcal/d received 75g/d nuts, ≈450kcal; ≤1,600kcal/d received 50g/d, ≈300kcal); 2) Test (Half Dose Nut Diet): Subjects received half dose of nuts and half dose of control muffin according to calorie needs; and 3) Control: whole wheat muffins were matched with energy content of nut supplements. One‐week weighed diet histories were obtained and fasting blood samples collected at baseline and weeks 2, 4, 8, 10 and 12 for markers of glycemic control and CHD risk factors.ResultsFinal data to be presented.
Immunological effects of polyphenols contained in Fermented Grape Marc (FGM) on human healthy peripheral blood cells
Authors: Jirillo Emilio , Marzulli G. , Jirillo F. , Tafaro A. , Kaneko M. , Kumazawa Y. , Amati L. 
Published: June 2021

The effects of polyphenols extracted from FGM of Negroamaro and Koshu wines were evaluated on human Peripheral Blood Mononuclear Cells (PBMC) in terms of regulatory, inflammatory and anti‐inflammatory cytokine production. Lyophilized FGMs were suspended in water or ethanol (100 mg/ml) and supernatants were added to 1 x 106 PBMC/ml in culture media. After 4 hours incubation at 37°C, cells were marked with anti‐human CD4 and CD14 moAbs, respectively . To study intracellular cytokine profile, cells were permeabilized and marked with anti‐human IL‐10, IL‐12 and TNF‐α moAbs, respectively. The analysis with the flow cytometer revealed that Koshu FGM markedly enhanced intracellular content of IL‐10 by CD4+ T cells when it was suspended in water but not in ethanol. On the other hand, Koshu greatly increased the enhanced intracellular of IL‐12 by CD14+ cells (monocytes) when it was suspended in ethanol but not in water. Negroamaro FGM was able to augment the intracellular content of TNF‐α by CD14+ cells, when it was suspended in water but not in ethanol. On the contrary, Koshu markedly enhanced the intracellular content of TNF‐α when it was suspended in ethanol but not in water. These results may represent a starting point for the use of FGM as modulators of the immune response in different pathologies as well as anti‐inflammatory agents via release of IL‐10 (e.g., Koshu suspended in water).This work was in part supported by MIUR and MIN. SALUTE (Rome, Italy).
Dissecting the Biological Function of NF‐¿B2p100
Authors: Yang Liqun , Ding Han‐Fei 
Published: June 2021

Nuclear Factor‐kappaB2 (NF‐¿B2), a member of the NF‐¿B family of transcription factors, has an important role in the development and function of the immune system. It is synthesized as a protein of 100‐kDa (p100). In response to certain cytokines, p100 undergoes proteolytic processing, leading to the generation of p52 that corresponds to the N‐terminal half of p100. p52 functions as a transcription activator with anti‐apoptotic activity; constitutive activation of p52 can lead to autoimmune inflammation. Previous in vitro studies have provided evidence that, in addition to serving as a precursor for p52, p100 functions as an I¿B molecule with the ability to restrain p52 activity. However, the physiological relevance of this I¿B activity of p100 has never been demonstrated. To address the question, I have generated p52 transgenic mouse lines with or without NF‐¿B2 p100. Compared to p52 transgenic mice carrying wild‐type p100 alleles, p52 mice deficient in NF‐¿B2 p100 show a marked increase in the mortality rate with severe inflammation in the lung, characterized by extensive infiltrations of lymphocytes and macrophages. Lymphocytes from these mice contain significantly higher levels of ¿B‐binding activity. These data demonstrate the function of p100 as a mechanism to limit the activity of p52, which has important implications in clinical control of inflammation.Supported by NCI Grant R01 CA106550 (to H.‐F. D.).
High molecular weight Fibroblast Growth Factor 2 (FGF2) requires an active Fibroblast Growth Factor Receptor 1 (FGFR1) to depress post‐ischemic cardiac function
Authors: Bodmer Janet R. , Wright Edward , Newman Gilbert , Schultz Jo El J. 
Published: June 2021

Fibroblast growth factor 2 (FGF2) is a family of isoforms with potential both as therapeutic molecules, as well as endogenous targets for pharmacological modulation in cardiac ischemia. Our laboratory has previously demonstrated that the secreted low moledular weight (LMW) FGF2 isoform protects the heart against myocardial dysfunction induced by ischemia‐reperfusion (I/R) injury by activating the FGF receptor 1 (FGFR1), while the mechanisms by which the high molecular weight (HMW) FGF2 isoforms produce the opposing and detrimental effects on cardiac function following I/R are less clear. The purpose of this study was to examine whether FGFR1 activation is necessary for the effects of HMW FGF2. Using an isolated work‐perfoming heart model, mice overexpressing the 24kDa isoform of FGF2 were subjected to global low‐flow ischemia in the presence of an inhibitor to FGFR1. The blockade of FGFR1 resulted in higher post‐ischemic contractility in transgenic hearts (p<0.05). We also found differences in the activation of kinases downstream from FGFR1, including protein kinase C (PKC) and mitogen activated protein kinases (MAPKs), indicating that HMW FGF2 alters the targets of FGFR1 signaling cascades. These findings indicate that HMW FGF2 mediates its effects by modulating FGFR1 signaling, to induce post‐ischemic myocardial dysfunction.Research supported by NIH grant NIH/NHLBI RO1 HL075633
The effect of cholinergic system in basolateral amygdala (BLA) on the ethanol–induced conditioned place preference (CPP)
Authors: Rostami Parvin , Zarrindast Mohammad Reza , Meshkani Javad , Rezayof Ameneh 
Published: June 2021

In this study the effects of bilateral injections of cholinergic agents into the basolateral amygdala (BLA) region on ethanol‐induced conditioned place preference (CPP) were investigated in male Wistar rats. Subcutaneous (s.c.) administration of different doses of ethanol (0.25, 0.5, 1, 1.5 g/kg) produced a partial dose‐dependent CPP as (0.5 g/kg) of ethanol was effective dose. Using a 3‐day schedule of conditioning, it was found that intra‐BLA administration of the nicotinic receptor agonist, nicotine (0.25, 0.5, 0.75,1 and 1.5 ìg/rat) significantly potentiated the ethanol (0.5 g/kg)‐induced CPP. Moreover, intra‐BLA administration of the muscarinic receptor agonist, pilocarine (0.5, 1 and1.5 ìg/rat), potentiated the ethanol (0.5 g/kg)‐induced CPP. Furthermore, intra‐BLA administration of nicotinic receptor antagonist, mecamylamine (0.5, 0.75 and 1 ìg/rat) before an effective dose of nicotine (1 ìg/rat) and Subcutaneous (s.c.) of ethanol (0.5 g/kg) decreased the effect of nicotine‐induced potentiation of the ethanol response. On the other hand, intra‐BLA administration of the muscarinic receptor antagonist, atropine (1, 2, and 4 ìg/rat) inhibited the effect of pilocarpine‐induced potentiation of the ethanol CPP. Intra‐BLA injections of nicotine, mecamylamine, pilocarpine or atropine alone did not induce a significant place preference or place aversion.Tmu research Grant
Defects in de novo neoangiogenesis in CD34KO mice revealed in a Matrigel chamber model
Authors: Heine Heather L , Baker Jennifer , So Leslie , Ajami Bahareh , Minchinton Andrew , Rossi Fabio , McNagny Kelly , McManus Bruce 
Published: June 2021

CD34 is a cell surface sialomucin widely used for hematopoietic stem cell (HSC) and endothelial progenitor cell (EPC) purification and as a marker of most vascular endothelial cells. Despite extensive research, the function of this sialomucin remains elusive. CD34‐deficient (CD34KO) strains of transgenic mice surprisingly have mild phenotypes, with no significant vascular defects. We took advantage of a subcutaneous in vivo Matrigel chamber model to systematically compare angiogenesis, endothelial, pericyte, white blood cell and adipocyte growth and migration in wild type and CD34KO mice. Using immunohistochemical staining for Hoechst 33342, CD31+, NG2+, F4/80, and perilipin, we revealed differences in the frequency of specific cell populations, rate of penetration and relative cell density. Endothelial cells appear to be defective in chambers grown within CD34KO mice. Chamber digestion and analysis of incoming cells by flow cytometry indicates Ter119+ cell numbers are elevated in chambers implanted in CD34KO mice for 6 weeks. Our data provide the first report of an endothelial phenotype in CD34KO mice. As well, the results illustrate how the chamber model of de novo tissue development may be an invaluable method for elucidating endothelial cell subsets that influence neoangiogenesis in vivo. This work is funded by the Canadian Institutes of Health Research.Grant Funding SourceCanadian Institutes of Health Research
Role of Adenosine A1 Receptors and P2Y2 Receptors and ERK1/2 Activation in Coronary Atherosclerosis and In‐stent Stenosis
Authors: Long Xin , Elosiebo Raven , Sturek Michael 
Published: June 2021

Proliferation of coronary smooth muscle cells (CSMC) plays a pivotal role in atherosclerosis and in‐stent stenosis (ISS). We made the novel discoveries that adenosine A1 receptors (A1R) and P2Y2 receptors via activation of ERK1/2 mediate mitogenesis in CSMC and intact coronary rings. Organ culture (OC) is a useful in vitro model of early coronary artery disease.HypothesisA1R and P2Y2 upregulation and ERK1/2 activation are important for coronary atherosclerosis and ISS. Bare metal stents (BMS) were placed and over‐expanded to 1.3 times normal coronary artery diameter in Ossabaw miniature pigs and ISS assessed after 1, 2, or 4 weeks of recovery. A1R protein and P2Y2 mRNA was upregulated in stented arteries after 1, 2 and 4 weeks of recovery and A1R protein peaked at 1 week, which preceded ISS that peaked at 4 weeks. CCPA, an A1R‐selective agonist, induced robust ERK1/2 activation in BMS vs. non‐stented artery segments. The P2Y2 mRNA was upregulated in coronary segments of 2‐day OC, preceding the development of early coronary atherosclerosis, shown by increased media thickness, collagen content, and nuclei number in coronary segments at 4‐day OC.ConclusionIn vivo and in vitro data are consistent with A1R and P2Y2 upregulation and activation of ERK1/2 causing coronary atherosclerosis and ISS. Support: NIH RR013223, HL062552, T35 HL007802, AHA Predoctoral Fellowship to X.L.Grant Funding SourceNIH, AHA
Peroxide mediates abnormal nitric oxide production in aged rat arteries
Authors: Zhou Xiaosun , Bohlen H Glenn , Unthank Joseph L , Miller Steven J 
Published: June 2021

Vascular oxidant stress increases with age and may cause dysregulation of the nitric oxide (NO) system. Our previous results have shown increased basal but suppressed flow‐mediated production of NO in aged resistance arteries that is corrected by antioxidant treatment. This study tested the hypothesis that H2O2 mediates abnormal NO production in resistance arteries of retired breeder (RB) rats. Animal groups consisted of young (Y) and RB Wistar Kyoto rats and RB pre‐treated with apocynin (RB+Apo). Microelectrodes were used to measure in vivo mesenteric artery H2O2 and NO simultaneously at baseline and during flow elevation by temporary occlusion of adjacent arteries. RB had significantly increased basal H2O2 compared with Y (15.6 ± 1.9 vs. 9.4 ± 0.9 uM, p< 0.05). Periarterial H2O2 levels were altered in proportion to flow changes in RB but not Y rats. In RB+Apo, H2O2 baseline was reduced to Y levels (8.2 ± 0.9 uM) and flow‐mediated H2O2 production inhibited. In RB, PEG‐catalase lowered baseline NO (1392 ± 211 to 576 ± 96 nM, p< 0.05) and restored flow‐mediated NO production (1060 ± 253 and 1826 ± 672 nM, 100 and 200% flow increase, respectively). The results suggest that elevated baseline and suppressed flow‐mediated NO production results from near maximal NO activation by H2O2 during aging, and imply that age‐related vascular dysfunction is not the result of reduced NO bioavailability.Support: HL42898 and HL20605.
Respiratory accommodations in Rhodnius prolixus in response to increased metabolic rates
Authors: Contreras Heidy Lorena , Bradley Timothy J 
Published: June 2021

It has been proposed that discontinuous respiration may have evolved in insects to decrease oxidative damage to tissues when at rest. However if metabolic rate (MR) increases, or the capacity of the respiratory system to deliver O2 to active tissues is altered, respiratory pattern in insects may change to meet aerobic demands. Specifically, we expect that as MR increases insects will transition from discontinuous (DGC) to cyclic and finally to continuous respiration. Preliminary studies have shown that a tenfold increase in MR (via temperature) in Rhodnius changed respiratory patterns from DGC to continuous respiration. However, Rhodnius respiratory responses due to feeding‐induced MR increase are not known. In Rhodnius prolixus metabolic rates (and body volume) may increase up to ten‐fold after a blood meal. They therefore provide an excellent model for studying the effects of specific dynamic action (SDA) on respiratory pattern. We expect that as metabolic rates increase, insects will transition to the different patterns as previously observed. However, due to the large effect of the meal on body volume and MR, differences in the overall MR required to induce the different patterns may be altered.Funding: APS Porter Physiology Development Award
Skeletal muscle fatigue is caused by either e‐c coupling, metabolic alterations mechanisms or both
Authors: Santos Bianca Maria Alves , Chang Ruzhang , Garcia Karla P.P. , Gonzalez‐Serratos Hugo 
Published: June 2021

Muscle fatigue may be due to a failure in excitation‐contraction coupling or an increase of ATP by products and NO. E‐c coupling alterations occur earlier and metabolic alterations take place later. We investigated these possibilities in frog skeletal muscle by continuous high frequency stimulation and different periods of repetitively stimulations. We judged the extent of e‐c or metabolic possibilities by releasing Ca2+ with 5 mM caffeine prior and immediately after fatigue.Continuously 60 Hz electric stimulations produced a force dropped to 0.33 ± 0.05 SD the control tetanus force, within a few seconds. The ratio of caffeine force development after and before fatigue was 1.02 ± 0.24 SD. This indicated that the interaction of myosin with actin was not impaired. After repetitive stimulation, the force dropped to 0.85 ± 0.04 SD (6 tetani) and 0.65± 0.11 SD (24 tetani) the control tetanus. Here, the ratio of caffeine force after and before fatigue development was 0.75 ± 0.3 SD. The concentration of caffeine used was the same as before therefore the acto‐myosin interaction was impaired during prolonged repetitive stimulations. The two types of fatigue take place.
Delayed recovery of dysferlin‐null muscle from injurious lengthening contractions is likely due to increased macrophage infiltration
Authors: Roche Joseph A , Vanapalli Renuka , Ru Lisa W , Lovering Richard M , Bloch Robert J 
Published: June 2021

The mechanisms underlying dysferlinopathies are unknown. As dysferlin mediates sarcolemmal repair in vitro, we hypothesized that it is necessary for normal recovery from lengthening contractions in vivo.METHODSWe studied the response to injury from 15 large‐strain lengthening contractions (LSI) or 150 small‐strain lengthening contractions (SSI) in the tibialis anterior muscle in dysferlin‐deficient, A/J (dysf‐) mice, and control, A/WySnJ (dysf+) mice.RESULTSImmediately after LSI and SSI, ~40% of torque was lost in both strains of mice. After LSI, dysf+ and dysf‐ muscles took 3 and 14 days, respectively, to recover completely; recovery in dysf‐ but not dysf+ was blunted by irradiation and accompanied by the loss of FDx‐labeled fibers 3‐14 days after injury, and significant myogenesis and inflammation. Recovery from SSI in dysf+ and dysf‐ muscles took 21 and 28 days, respectively; neither strain retained FDx 3 days after injury, and both showed significant myogenesis and inflammation, though inflammatory cell numbers were 5‐fold greater in dysf‐. Most infiltrating cells were CD68+ macrophages. Irradiation limited recovery to ~60% and ~50% of pre‐injury torque in dysf+ and dysf‐ muscles, respectively, but had no effect on inflammation.CONCLUSIONSDelayed recovery of dysf‐ muscle from lengthening contractions is associated with decreased myofiber survival and increased macrophage infiltration.This work was funded by the Jain Foundation.
Diet‐induced obesity alters skeletal muscle satellite cell functional capacity.
Authors: Shortreed Karin Elizabeth , Huang Julianna H , Dhanani Dili , Hawke Thomas J 
Published: June 2021

Skeletal muscle satellite cells are integral for normal muscle growth. As skeletal muscle is the largest organ for blood glucose disposal, we were interested to ascertain whether a high fat diet (HFD) would negatively impact muscle satellite cells, and thus have a negative impact on skeletal muscle growth.Using isolated, intact single fibers, we found that the number of satellite cells in an 'activated state' was significantly enhanced (159 ± 21% of control) while their proliferative capacity was significantly impaired (55 ± 9 % of control).Preliminary analysis of cells isolated from HFD muscle demonstrate neither a significant impairment in migration capacity, using a Boyd's filter chamber, nor in the ability to fuse or express myosin heavy chain after 48 and 96 hours of exposure to differentiation media.These preliminary findings suggest that HFD induces a satellite cell state similar to that found in atrophic muscle, where there is an initial enhancement in activation and impairment in proliferative ability. Alternative techniques for assessing satellite cell activation and proliferation are ongoing to confirm these results. Importantly, the potential irreversible effects of diet‐induced obesity on satellite cell function in young muscle requires further investigation to fully define the implications on long‐term muscle growth and regeneration.
Pro‐inflammatory / Pro‐fibrotic effects of Interleukin‐17A on human proximal tubule epithelium
Authors: Dudas Paul L , Sague Sarah L , Elloso M. Merle , Farrell Francis X 
Published: June 2021

Chronic allograft nephropathy is manifested by inflammation and tubulointerstitial fibrosis. IL‐17A is a T‐cell‐derived cytokine upregulated in allograft nephropathy, therefore, the present study sought to characterize the actions of IL‐17A on human proximal tubule epithelium.First, pro‐fibrotic gene expression was examined by real‐time PCR in human proximal tubule cells following treatment with IL‐17A. e‐cadherin was significantly decreased while CTGF, CD44 and TGFβR1 were increased. These changes were reduced by anti‐IL‐17A antibody treatment. Next, IL‐17A‐stimulated soluble mediator secretion was examined. IL‐17A induced the secretion of fractalkine, G‐CSF, GM‐CSF, VEGF, IL‐6 and IL‐8. Finally, ZO‐1 expression was examined by immunocytochemistry as an indicator of epithelial integrity. Treatment with IL‐17A caused a substantial downregulation of ZO‐1 that was inhibited by anti‐IL‐17A antibody treatment.These data indicate IL‐17A can induce the upregulation of genes associated with ECM remodeling and cell‐cell interaction, and stimulate secretion of inflammatory mediators and immune cell chemoattractants. IL‐17A decreased ZO‐1 protein expression indicating it may negatively impact epithelial barrier function. Thus, IL‐17A may play an important role in the progression of chronic renal injury through the above‐described mechanisms. Centocor is a Johnson & Johnson company.
Application of lymphocytes as model for proteolytic activation of ENaC
Authors: Friis Ulla G , Bistrup Claus , Jensen Boye L 
Published: June 2021

We have recently identified plasmin as an activator of epithelial Na+ channels (ENaC) in urine from humans and rats with nephrotic syndrome (1). Lymphocytes express ENaC similarly to ENaC in renal principal cells. We therefore wanted to study if human lymphocytes could be used as a model for proteolytic activation of ENaC. Human lymphocytes were isolated from peripheral blood samples from healthy young males. When lymphocytes were flushed with urine from control rats, it did not significantly increase sodium currents, while when flushed with urine collected on day 4 after puromycin injection resulted in a 4.24 ± 0.97 fold increase in the sodium current compared to controls (control ‐77 ± 11 pA vs. nephrotic urine ‐240 ± 17 pA, n=4, P <0.005). The stimulatory effect was blocked by pre‐treatment of nephrotic urine with aprotinin (700 μg/mL), which is an inhibitor of serine proteases. The identity of the sodium current was further established by blockade of the current with 2 μmol/L amiloride, which is specific for ENaC inhibition when used in this concentration. These data thus confirm the applicability of lymphocytes in the study of ENaC.This study was supported by grants from the Danish Research Agency and the Novo Nordisk Foundation.(1) Svenningsen S et al. JASN: in press.