bluuebunny/crossref_metadata_2025 huggingface dataset:
Kupffer cells are stimulated by cellular fibronectin to produce factors that could further promote alcohol‐induced liver injury
Authors: Aziz‐Seible Razia Sultana , Lee Serene M , Casey Carol A
Published: June 2021

Previous studies from our laboratory have shown that ethanol‐induced alterations in asialoglycoprotein‐receptor (ASGP‐R) activity causes impaired receptor‐mediated clearance of its ligands, including cellular fibronectin (cFn). In this study, we evaluated the effect of impaired clearance of cfn to better understand how this could contribute to fibrotic injury. Kupffer cells were isolated from rats fed a control or ethanol liquid diet for four to six weeks. The effect of exogenous cFn on Kupffer cell viability and secretions was determined over 20 hours of cell culture. The viability (apoptosis and necrosis) of both cell types remained unaffected by treatment with cFn. Pro‐inflammatory cytokine (TNF‐α and IL‐6) production was increased in both cell types in the presence of cFn, with cells from ethanol‐fed animals secreting higher levels of both cytokines as compared to controls. When MMP‐2 and TIMP‐2 levels were measured by gelatin zymography and Western blot analysis, we found that cFn stimulated a dramatic increase in both control and ethanol cells. These data show that Kupffer cells are stimulated by the presence of excess cFn to produce factors that may potentially enhance the promotion of tissue injury, and that ethanol administration increases these responses. Research Support: NIH F31 AA168632
Cyclic stretch‐induced proliferation in rabbit proximal tubular cells involves cPLA2, ERK, and c‐Src
Authors: Alexander Larry D
Published: June 2021

Increased intrarenal pressure, in unilateral uretal obstruction (UUO), is considered a major event leading to persistent tubular cell proliferation. The mechanical signal produced by UUO is assumed to be tubular stretching, but the molecular mechanisms involved in this process are poorly understood. In the present study we investigated whether a "physiological" level of stretch (5%) or a more injurious magnitude of stretch (15%) can induce proliferation in kidney epithelial cells. To produce strain or stretch, primary cultures of rabbit proximal tubular cells were grown in tissue culture wells having collagen‐coated Silastic deformable membrane bottoms and exposed to 5% or 15% stretch for 6 h or 24 h. We found that cyclic stretch significantly induced the proliferation of rabbit proximal tubular cells at both 5% and 15% strain for 24 h. Inhibition of PLA2 by AACOCF3 or with the antisense oligonucleotide treatment designed to silence cPLA2 expression, EK 1/2 by PD98059 and c‐Src by a selective inhibitor for the Src kinase family, PP2 or with a dominant‐negative (DN) mutants of c‐Src, blocked the cyclic stretch‐induced proliferation. Overall, this study demonstrates, for the first time, that cyclic mechanical stretch induces the proliferation of rabbit proximal tubular cells and suppresses their mitogenic affect through the activation of cPLA2, ERK and c‐Src.
Consumption of a western diet and the pancreatic O‐GlcNAc response
Authors: Marsh Susan A , Dell'Italia Louis J , Chatham John C
Published: June 2021

Consumption of high fat diets typically result in insulin resistance and elevated circulating insulin levels; however, recent rodent studies have demonstrated that a western diet high in both fat and carbohydrate depresses insulin levels. It has been suggested that increased protein levels of β‐N‐acetyl‐glucosamine (O‐GlcNAc) promotes β‐cell dysfunction. Therefore, the aim of this study was to examine the effects of short‐term consumption of a western diet on the pancreas. Young male rats received control (CON; 12% kcal fat/19% protein/69% carbohydrate) or western (WES; 40/15/45%) diets for 2 weeks. Insulin sensitivity was 34% and plasma insulin 50% lower in WES whereas blood glucose remained similar between groups (6.5 ± 0.2 mmol/l CON vs 6.0 ± 0.2 mmol/l WES). At the protein level, there was no evidence of accumulation of advanced glycation end‐products (AGE) or endoplasmic reticulum stress (HSP47, GRP78) in WES and there were negligible levels of TUNEL‐positive cells in both groups. Histological analyses revealed decreased levels of protein O‐GlcNAcylation in WES compared to CON in both islet and non‐islet regions of the pancreas with equivalent levels of insulin staining and islet size. These data suggest that decreased protein O‐GlcNAcylation may contribute to dysregulation of insulin production and/or secretion in the pancreas following short‐term consumption of a western diet.
Distinct Agonist‐Induced Contraction in Intra‐ and Extra‐Renal Arteries under High‐Glucose Conditions
Authors: Nobe Koji , Tsumita Naoki , Nezu Yumiko , Honda Kazuo
Published: June 2021

The renal artery (RA) has been extensively investigated as a model for the assessment of renal vascular function/dysfunction; however, few studies have focused on the intrarenal vasculature. We measured contractile responses in mouse interlobar artery (ILA) in this study. Treatment of RA with 10 μM phenylephrine (PE), 10 nM U46619 (thromboxane A2 analog) or 10 μM prostaglandin F2α elicited a response greater than 150% of the 50 mM KCl‐induced response (1698.7±323.4 μN/mm; n=5). In ILA, 10 nM U46619 produced a response that was 130% of the KCl‐induced response (784.0±56.6 µN/mm; n=5); however, other agonists induced levels similar to that of the KCl‐induced response. These results revealed that extra‐ and intrarenal arteries possess different agonist‐induced contractions. Under high‐glucose conditions (22.2 mM glucose), contractile responses in RA and ILA were enhanced significantly following PE and U46619 stimulation, respectively. Enhancement was suppressed by a calcium‐independent protein kinase C (PKC) inhibitor. Our findings suggested that only the U46619, induces enhanced contractility in ILA, which might lead to renal dysfunction and nephropathy via reduced intrarenal blood flow rate.
Exercise reverses aging‐associated myocardial insulin resistance by restoring eNOS‐mediated mitochondrial response to insulin
Authors: Li Qiu‐Xia , Zhang Quan‐Jiang , Li Jia , Zhang Hai‐Feng , Guo Wen‐Yi , Wang Hai‐Chang , Gao Feng
Published: June 2021

The present study sought to evaluate myocardial insulin resistance (IR) with a specific focus on eNOS and its correlation with mitochondrial function, and further examined the impact of exercise on myocardial IR during aging. Aged male Sprague‐Dawley rats (24‐month‐old) were subjected to free‐of‐loading swim training (60 min/d, 5 d/wk, 10 wk). Glucose uptake, mitochondrial function, myocardial contraction, and eNOS signaling were evaluated. Aging triggered myocardial IR as shown by decreased glucose uptake by insulin (0.22±0.05 μmol/min/g in aged heart vs.1.29 ± 0.13 μmol/min/g in adult heart, n=8, P<0.01). Mitochondrial O2 consumption in response to insulin was markedly decreased in aged heart (1.37±0.31 μmol/min/g in aged heart vs. 2.35±0.31 μmol/min/g in adult heart, P<0.01). In addition, eNOS expression and its phosphorylation by insulin were reduced by 1.2‐ and 2.3‐fold in aged heart, respectively (P<0.01). Exercise upregulated eNOS expression by 72% (P<0.01), facilitated eNOS phosphorylation by insulin (P<0.01), and ameliorated myocardial IR as shown by enhanced glucose uptake by insulin (P<0.01). Moreover, pretreatment with either eNOS inhibitors (L‐NAME or Cavtratin) or a mitochondrial oxidative phosphorylation inhibitor (FCCP) blunted exercise‐improved insulin sensitivity, and exercise‐triggered mitochondrial response to insulin in aged heart. These results indicate that exercise ameliorates aging‐associated myocardial IR by partly rescuing mitochondrial response to insulin in an eNOS‐dependent manner.
The basal rate of muscle protein synthesis and its response to hyperinsulinemia‐hyperaminoacidemia are the same in young men and women
Authors: Smith Gordon I , Reeds Dominic N , Mohammed B Selma , Jaffery Hadia , Mittendorfer Bettina
Published: June 2021

We have recently shown that there are considerable sex differences in muscle protein turnover in 65‐80 year old adults. Specifically we found that the basal rate of muscle protein synthesis (MPS) is greater in elderly women than elderly men whereas the anabolic response of MPS to feeding is greater in elderly men than elderly women (PLoS One 3:1875‐83, 2008). The purpose of this study was to determine whether similar differences in muscle protein metabolism exist in younger individuals. We therefore measured the rate of MPS during basal, postabsorptive conditions and during combined hyperinsulinemia and hyperaminoacidemia by using stable isotope‐labeled tracer techniques in 7 men and 5 women, who were matched on age (mean ± SEM: 40 ± 2 y vs 38 ± 3 y, respectively; P = 0.63) and body‐mass index (26.2 ± 1.1 kg.m2 vs 25.8 ± 1.3 kg.m2, respectively; P = 0.84). The basal rate of MPS was not different in men (0.041 ± 0.006 % ·h−1) and women (0.040 ± 0.006 % ·h−1). Hyperinsulinemia‐hyperaminoacidemia resulted in a significant increase in the rate of MPS (P < 0.001) in both men (to 0.062 ± 0.007 % ·h−1) and women (to 0.064 ± 0.010 %·h−1) with no difference (P = 0.71) in the magnitude of the anabolic response. Thus, sexual dimorphism in muscle protein turnover is a phenomenon associated with old age. The underlying mechanism(s) remain to be elucidated but are probably due to sex specific hormonal changes that accompany the aging process in men and women.

This research was supported by grants from the US NIH.
Glucose deprivation induced increase in O‐GlcNAc levels in cardiomyocytes is not mediated via increased OGT expression
Authors: Zou Luyun , Marchase Richard B , Chatham John C
Published: June 2021

O‐Linked N‐acetylglucosamine (O‐GlcNAc) is a post‐translational modification of proteins that plays an important role in mediating the response of cells to stress. Previous studies in human hepatocellular carcinoma and Neuro‐2a neuroblastoma cells demonstrated that glucose deprivation increased O‐GlcNAc levels by up‐regulation of O‐GlcNAc transferase (OGT) in an AMP‐activated protein kinase‐dependent manner. The goal of this study was to examine the effect of glucose deprivation (GD) on O‐GlcNAc levels in neonatal rat ventricular cardiomyocytes (NRVM). GD significantly increased NRVM O‐GlcNAc levels within 1‐2 hours and O‐GlcNAc levels continued to increase over the next 6 hours. GD increased p38 and Akt phosphorylation, but had no effect OGT protein levels. Increasing hexosamine biosynthesis with glucosamine (5mM) significantly attenuated the effects of GD; however, inhibition of OGT (Alloxan, 5mM or TT04, 5µM) or O‐GlcNAcase (PUGNAc or NAG‐Bt, 100µM) had no effect. Surprisingly, inhibition of capacitative calcium entry (CCE) with SKF 96365 (5μM) markedly inhibited GD‐induced increase in O‐GlcNAc. These results demonstrate that GD rapidly increases O‐GlcNAc levels in NRVM independent of changes in OGT expression. The mechanism underlying the GD‐induced increase in O‐GlcNAcylation in NRVMs remains to be determined; however, it appears to be mediated at least in part via hexosamine biosynthesis and CCE. (Supported by NIH grants: HL067464 and HL079364)
Phylogenetic modeling of endometriosis gene expression
Authors: Carney Elissa Justine , Amri Hakima
Published: June 2021

Endometriosis is the growth of endometrial glands and stroma outside the normal lining of the uterine cavity. Ten to twenty percent of American women develop endometriosis, with forty percent diagnosed infertile. It is an enigmatic disorder, as the etiology and pathophysiology remain unresolved. Our objective was to reveal clonally altered gene expression and identify a genomic biosignature for endometriosis using a phylogenetic analysis of gene‐expression microarray data. Data was polarized and coded into derived and normal states, followed by a maximum parsimony analysis to produce a cladogram representing the genomic classification based on the shared derived characters‐the synapomorphies. Gene linkage was modeled by Genomatix BiblioSphere Pathway Edition software. The analysis identified 1875 clonally altered genes involved in reproductive functions, carcinogenesis, cytoskeleton, apoptosis, immune function, cell proliferation, and the Ras‐Mek‐MAPK pathway. This novel strategy produced a list of clonally shared altered expressions in all the specimens analyzed, and revealed a massive disruption of major regulatory pathways. Interestingly, a number of genes are also involved in gynecologic carcinogenesis. Our analysis exposed genes that may be involved in the malignant transformations within endometriosis cases associated with endometrioid ovarian carcinoma.
Intermittent hypoxia (IH) causes greater insulin resistance than chronic hypoxia (CH) in lean mice
Authors: O'Donnell Christopher Paul , Strollo Hilary C , Romano Lia C , Skalka Kristy , Rosa Taylor C , Stefanovski Darko , Bergman Richard N , Garcia‐Ocana Adolfo , Alonso Laura C
Published: June 2021

INTRODUCTION

Sleep apnea is characterized by IH and is associated with metabolic dysfunction. We developed the first frequently sampled intravenous glucose tolerance test (FSIVGTT) in conscious mice to examine the effects of IH and CH on glucose disposal.

METHODS

Adult male C57BL/6J mice with chronic femoral artery and venous catheters were exposed to seven hours of either IH (nadir inspired oxygen 5‐6% at 60 cycles hr−1) or CH (constant 10% FIO2). Control groups were exposed to either intermittent air (IA) or were unhandled (UH). A FSIVGTT was performed by rapidly sampling arterial blood for glucose (and insulin) at (‐10), (0), (1), (2), 3, (4), 5, 6, (8), 10, (12), 14, (16), 18, (20), 25, (30), 40, 50, (60), (90), and (120) min after a bolus injection of i.v. glucose (1 g/kg). Data analysis was performed in collaboration with the Bergman group at USC utilizing the previously validated Minimal Model program.

RESULTS

Compared with the UH and IA groups, the IH group demonstrated a decrease in glucose effectiveness (Sg), and marked decreases in insulin sensitivity (SI) and the Disposition Index (DI) for glucose. The CH group also showed a decrease in Sg, but SI and DI were not as impaired compared to IH. * p<0.05 vs UH/IA control; # p<0.05 IH vs CH.

CONCLUSION

IH is a unique paradigm of hypoxic stress that specifically induces insulin resistance and impairs the disposition of glucose into the peripheral tissues.

Supported by NHBL063767
A TRPM4‐LIKE NON‐SELECTIVE CATION CHANNEL IS EXPRESSED IN SMALL INTESTINAL EPITHELIAL CELLS
Authors: Bao Hui‐Fang , Duke Billie J , Eaton Douglas C
Published: June 2021

We used patch‐clamp techniques to characterize ion channels that are expressed in the apical membrane of small intestinal epithelial IEC6 cells. A nearly silent 23‐pS channel was recorded in cell‐attached patches, which was significantly activated when the intracellular Ca2+ was elevated by ionomycin. The channel was also strongly activated in excised inside‐out patches when the inner leaflet of the patch membrane exposed to 1 mM Ca2+, Change in Cl− gradient across the patch membrane did not affect the reversal potential. In contrast, the replacement of Na+ with NMDG+ in the patch pipette obviously shifted the reversal potential from 0 to ‐60 mV, which is very close to the equilibrium potential calculated according to the concentration gradient of Na+. However, the replacement of Na+ with K+ in the patch pipette did not affect the reversal potential. These biophysical properties are similar to those of native and expressed TRPM4 characterized in other types of cells. Recent studies suggest that the melastatin subfamily 4 of transient receptor potential channels (TRPM4) plays an important role in modulating the cell membrane potential. Therefore, we also performed confocal microscopy experiments and found that TRPM4 is expressed in IEC6 cells. These data suggest that a TRPM4‐like nonselective cation channel may regulate the transport function of small intestinal epithelial cells by affecting the membrane potential.
Role of CFTR in migration of airway epithelial cells
Authors: Schiller Katherine R , O'Grady Scott M
Published: June 2021

The role of CFTR in airway epithelial wound healing was assessed with Calu‐3 and NHBE airway epithelial cells in real time by measuring changes in impedance (Z) as cells migrated onto the surface of an electrode to close a wound in the epithelium. Inhibition of CFTR activity with CFTRinh‐172 slowed the rate of wound closure (time to reestablish initial Z) in Calu‐3 cells (30 μM) by 6.2 hours compared to control (serum free media, 1 μg/ml EGF, DMSO), and in NHBE cells (20 μM) by 10.0 hours compared to control (serum free media, DMSO). A CFTR specific effect on cell migration was verified in Calu‐3 cells by constitutive expression of CFTR specific shRNA, which resulted in >99% reduction of CFTR transcript. Silencing CFTR in Calu‐3 cells delayed wound closure by 24.3 hours compared to ALTER shRNA expressing and wild type Calu‐3 cells. Replacement of Cl− ions with SO4− and gluconate in the media during Calu‐3 cell migration had no effect on cell migration rate. However, reduction of [HCO3−] from 26 mM to 5 mM in HEPES buffered CO2 gassed media slowed the rate of Calu‐3 cell migration by 3.7 hours, in the absence of a change in intracellular pH. The results of these experiments indicate that functional activity of CFTR is involved in Calu‐3 and NHBE cell migration and suggest a role for CFTR in airway epithelial restitution. Further, these results suggest that HCO3− transport mediated by CFTR is necessary for efficient cell migration.
POSH (Plenty of SH3) is an E3 ligase of ROMK (Kir1.1) channels in cortical collecting duct (CCD)
Authors: Pan Chunyang , Lin Daohong , Yue Peng , Wang Wenhui
Published: June 2021

The aim of the present study is to explore the role of POSH in the regulating ROMK channels. Immunostaining shows that POSH is expressed in the CCD. Moreover, GST pull‐down, immunoprecipitation and in vitro protein chemistry studies have demonstrated that POSH is associated with ROMK channels in its N‐terminus. Co‐expression of POSH decreased K current in a dose‐dependent manner in oocytes injected with ROMK1 channels. The effect of POSH on ROMK1 channels was specific because POSH did not inhibit Na channels in oocytes injected with ENaC‐alpha, beta and gamma subunits. Surface labeling with biotin shows that POSH decreased the membrane expression of ROMK channels in 293T cell transfected with both. The ubiquitinlation assay has further demonstrated that POSH enhanced the ubiquitinlation of ROMK channels in 293T cells transfected with ROMK1 and POSH. The notion that POSH may act as an E3 ubiquitinligase of ROMK is also indicated by in vitro ubiquitin assay in which adding POSH increased the ubiquitination of ROMK1. Finally, ubiquitinlation of ROMK1 is absent in cells transfected with truncated POSH in which RING domain was deleted. We conclude that POSH is an E3 ubiquitin ligase for ROMK channels.
Long‐Chain n‐3 Fatty Acids and Insulin‐Regulated Metabolism in Healthy Old Lean Rats
Authors: Thivierge M. Carole , Mackie Claire , Calder Graham
Published: June 2021

This study assessed for the first time whether feeding EPA and DHA at a physiological dose to healthy, old, lean, Hooded Lister male rats aged of 14 months improves metabolic defects accompanying the ageing‐associated deterioration in insulin sensitivity. Rats were fed a basal semi‐purified diet meeting requirements (16.2 MJ/kg; 5.0% CP, 6.5% fat). Control oil or EPA & DHA supplements were fed over 60 d. Rats had similar intake (15 g/d), weight gain (625 to 649 g; P > 0.10) and body fat (21% MRI fat; P > 0.10). A mild loss in lean body mass (LBM) was monitored over the 2‐month period (530 to 515 g; P = 0.07 tendency). LCn‐3FA was numerically associated to lower age‐associated loss in LBM (‐18.8 vs. ‐9.7 g; P = 0.11). LCn‐3FA reduced fasting TG (2.37 vs. 1.85 mmol/l; P < 0.03) and LDL cholesterol (0.27 vs. 0.15 mmol/l; P < 0.001). Six‐h kinetics of D‐[U‐13C]glucose were conducted during an insulin‐stimulated state induced through an i.v. nutrition of dextrose and amino acids. Whole‐body glucose turnover was increased (99 to 106 µmol/kg·min; P = 0.02) in LCn‐3FA‐fed rats. This increased turnover combined to similar exogenous dextrose entry (81 µmol/kg·min) was sustained through increase in endogenous glucose production (19 to 25 µmol/kg·min; P = 0.04). LCn‐3FA supplement may be a novel approach to intervene on certain ageing‐associated deteriorations of metabolism.
Hypoxia and zinc induced changes in the contractile machinery of isolated rat pulmonary microvascular endothelial cells (RPMVECs)
Authors: Bernal Paula Jimena , Watkins Simon Charles , St Croix Claudette Marie
Published: June 2021

Our recent data suggest that hypoxic induced increases in NO biosynthesis result in increases in intracellular free zinc that in turn contribute to vasoconstriction of small, non‐muscularized intra‐acinar arteries (<50 um). In order to understand the cellular changes behind this contractile behavior, we examined actin‐myosin dynamics and focal adhesion changes in isolated rat pulmonary microvascular endothelial cells (RPMVEC) in response to 30 minutes of hypoxia or exogenously applied zinc. Immunocytochemistry and confocal analysis showed that contraction in response to either 2% oxygen or zinc, were accompanied by increases in actin‐myosin interactions; stress fiber formation; and recruitment of focal adhesion proteins to cell‐matrix contacts. Live cell imaging of GFP tagged proteins provided real‐time information about the strengthening and alignment of actin stress fibers while total internal reflection (TIRF) imaging showed recruitment of paxillin, talin and zyxin to focal adhesions. These data suggest that the reorganization of cytoskeletal and focal adhesion proteins in response to hypoxia or zinc may be responsible for the force induction and cell stability necessary to elicit an active contractile response in pulmonary endothelium.

Funded by NIH HL 081421 (CMS)
Effect of short transmembrane peptides on the activation and dimerization of a FGFR3 pathogenic mutant
Authors: He Lijuan , O'Connor Shannon K , Shobnam Nadia , Hristova Kalina
Published: June 2021

Mutations in the transmembrane domains of receptor tyrosine kinases (RTKs) are implicated in many human diseases. For example, fibroblast growth factor receptor 3 (FGFR3) carrying an A391E mutation in the transmembrane (TM) region is associated with bladder cancer and Crouzon syndrome with acanthosis nigricans. Previous work has shown that the isolated FGFR3 TM domains dimerize in detergent micelles and in lipid bilayers. Therefore, we are exploring whether the TM domain of FGFR3 can inhibit the pathogenic effects of the A391E mutation. Our preliminary data show that the activation level of a chimeric Neu_FGFR3 receptor carrying the A391E mutation could be inhibited by co‐expressing short mutant FGFR3 TM peptides. We also observe a decrease in dimerization propensity of the receptors due to the co‐expression. Currently, we are investigating the specificity and the efficiency of the inhibition by using TM peptides from other RTKs. The TM peptides which can specifically and efficiently inhibit the activation and dimerization of FGFR3 mutants are possible candidates for future therapies for diseases linked to FGFR3 TM domain mutations.
Proteomic analyses of defence gene expression in a model tomato‐Verticillium pathosystem
Authors: Robb Jane , Lee Barbara , Kurosky Alex , Nazar Ross N.
Published: June 2021

Relatively little is known about the molecular mechanisms utilized by plants to defend themselves against fungal vascular pathogens. Based on DNA microarray analyses, in past studies we used a model tomato‐Verticillium pathosystem to compare the global expression of genes in compatible and incompatible interactions. While very significant patterns of mRNA changes were defined, how these are translated at the protein level remained unclear. In the present study, 2D gel electrophoresis and proteomic analyses were applied to evaluate the actual changes in protein levels. Whole cell protein was extracted simultaneously with RNA to permit parallel comparisons of both mRNA and proteins from the same samples. Proteins representing 13 of the most intense changes were identified using mass spectrometry. Three were products of commonly identified pathogenesis related genes, three were peroxidase related and two were osmotin related proteins, all products of genes commonly reported to be involved in genetic responses to stress or pathogens. The levels of induction relative to other cellular proteins were particularly striking, an observation which underlines the plant's heroic systemic response to a vascular disease such as Verticillium wilt.
Redox‐switch modulation of human SSADH by dynamic catalytic loop
Authors: Kim Kyung‐Jin , Kim Yeon‐Gil , Kim Yeon‐Gil
Published: June 2021

Succinic semialdehyde dehydrogenase (SSADH) is involved in the final degradation step of the inhibitory neurotransmitter gamma‐aminobutyric acid (GABA) by converting succinic semialdehyde (SSA) to succinic acid in the mitochondrial matrix. SSADH deficiency, a rare autosomal recessive disease, exhibits variable clinical phenotypes, including psychomotor retardation, language delay, behavior disturbance, and convulsions. Here we present crystal structures of both oxidized and reduced forms of human SSADH. Interestingly, the structures show that the catalytic loop of the enzyme undergoes large structural changes depending on the redox status of the environment, which is mediated by a reversible disulfide bond formation between a catalytic Cys340 and an adjacent Cys342 residues located on the loop. Subsequent in vivo and in vitro studies reveal that the ¡(r)dynamic catalytic loop¡ confers a response to reactive oxygen species (ROS) and changes in redox status, indicating that the redox‐switch modulation could be a physiological control mechanism of human SSADH. Structural basis for the substrate specificity of the enzyme and the impact of known missense point mutations associated with the disease pathogenesis are presented as well.

This work was funded by 21C Frontier Microbial Genomics and Application Center Program, Ministry of Education, Science and Technology (MEST), Republic of Korea.γ
Dipyridamole Enhancement of Diabetic Ischemia Induced Angiogenesis
Authors: Branch Billy Glynn , Greber Eric , Pattillo Christopher , Kevil Christopher
Published: June 2021

Background

Peripheral Artery Disease and critical limb ischemia affect millions of Americans with an alarming increase in diabetics. There is a need for therapeutic restoration of vascular function in those affected by these diseases. We studied the hypothesis that dipyridamole could be used for angiogenic preconditioning due to its relationship with eNOS expression and activation in various tissue sites.

Methods

Hind limb ligations were performed in dipyridamole and control db/db diabetic mice. Serial laser Doppler blood flow measurements were taken on days 0, 3, 5, and 7. CD31, DAPI, and Ki67 immunofluorescent staining was used to evaluate vascular densities and active endothelial cell proliferation. Tissue and blood nitrite measurements were collected to confirm a rise in nitrite levels after treatment.

Results

Our experiment showed that dipyridamole significantly increased blood flow and vascular density. Blood flow levels were returned to 98.4±4.1% of pre‐ligation blood flow by day 7 in the dipyridamole dosed mice as compared to 58.2±4.5% at day 7 in the control mice. Immunofluorescent staining values were significantly increased in the ischemic limbs of dipyridamole dosed mice as compared to control mice showing that dipyridamole selectively increases ischemic hind limb vascular density and endothelial cell proliferation. Tissue nitrite levels were significantly elevated in dipyridamole dosed mice as compared to control mice.

Conclusion

Our results show that dipyridamole has great potential as a preconditioning and angiogenesis stimulating agent in diabetic chronic ischemia.
Isotopomer analysis of 3‐hydroxybutyrate by liquid chromatography tandem mass spectrometry to determine ketogenic flux
Authors: Sunny Nishanth E , Fu Xiaorong , Satapati Santhosh , He TianTeng , Burgess Shawn C
Published: June 2021

Hepatic ketogenesis maintains critical systemic fuel supply during fasting, mainly from acetyl‐CoA derived from fatty acid oxidation. Ketogenesis is coupled to beta oxidation and TCA cycle and is often dysfunctional in patho‐physiological conditions including insulin resistance and diabetes. Further, quantifying ketogenesis is challenging due to the unstable nature of acetoacetate (ACAC) and the substantial sample volume (3‐4 mL plasma) required for detecting ketones by NMR spectroscopy. This method determines both ACAC and 3‐hydroxybutyrate (3‐BHB) enrichments in ~25 µL blood or plasma by isotopomer analysis of 3‐BHB using LC‐MS/MS. Following a 90 min intravenous infusion of [3,4‐13C2]ACAC (M+3) and [1,2,3,4‐13C4]3‐BHB (M+4), the blood or plasma ACAC was reduced to 3‐BHB (M+1) with sodium borodeuteride. Steady state enrichments of the ketone tracers, 3‐BHB derived from ACAC (M+2) and ACAC derived from 3‐BHB (M+5) were used to quantify ketogenesis using a two pool model. Ketogenesis measured by LC‐MS/MS in 24 h fasted Long Evans rats yielded similar values to those measured by NMR spectroscopy. Ketogenesis in insulin resistant obese mice was lower than the controls suggesting a dysfunction in channeling fatty acid carbon through central metabolic pathways in the liver. In summary, this method provides a sensitive and reliable index of ketogenesis by monitoring only 3‐BHB in micro liters of blood or plasma.
Anthocyanin protects Raw264.7 cell from ox‐LDL by decreasing CHOP expression in mRNA level
Authors: Zhang yemin , Wang Baohua , Zhang Deling , Ouyang Jingping
Published: June 2021

Cardiovascular diseases, especially artherosclerosis is responsible for the majority of deaths in the world. Ox‐LDL is an important factor in the progress of artherosclerosis. To find an effective drug or method to treat artherosclerosis, we use three antioxygens, sodium ferulate, tBHQ and anthocyanin to administrate serum starved Raw264.7 cell treating with 40mg/L ox‐LDL for 24 hours. Cytoactive was detected by MTT. We found that only anthocyanin could protect cells from ox‐LDL, and the effect was independent on concentration. CHOP (also known as growth arrest and DNA‐damage‐inducible protein GADD153) is en endoplasmic reticulum stress‐inducible protein that plays a critical role in the regulation of cell death. Gene chip (Affymetrix Mouse 4302.0 microarray) and RT‐PCR found that the mRNA of CHOP decreased in anthocyanin treating group. Therefore, we conclude that anthocyanin may protect cells by decreasing CHOP expression in mRNA level. This will provide us a new clue to cure arteriosclerosis.
Easy accessibility to a vegetable beverage can result in a marked increase in vegetable intake: an approach to improving vascular health
Authors: Shenoy Sonia , Kazaks Alexandra , Holt Roberta , Winters Barbara , Khoo Chor San , Keen Carl
Published: June 2021

USDA 2005 Dietary Guidelines emphasize the need for increasing vegetable consumption. However, most Americans do not meet the 2005 guidelines. This 12 week study was designed to determine if incorporation of a vegetable juice in conjunction with Dietary Approach to Stop Hypertension (DASH) diet education would improve vegetable intake and reduce select cardiovascular risk factors in adults (40‐65 yrs). Subjects (n=90: 24 male, 66 female) were randomly assigned to 1 of 3 groups (0, 1 cup or 2 cups vegetable juice). On average, subjects did not meet vegetable recommendations, unless they consumed the juice. After 12 weeks, in all groups, even with counseling on vegetable intake in their diets, only 12.5% met minimum DASH vegetable recommendations. However, when juice consumption was included, 46%, and 100% of the subjects in the 1‐ and 2‐cup groups, respectively, met DASH recommendations, compared to 7% in the 0 group. No significant within‐ or between‐ group changes were observed for BMI, hsCRP, TBARS, lipids or blood pressure from baseline. However, after 12 wks, in pre‐hypertensive subjects with systolic blood pressure (SBP) 120‐140 mm Hg and/or 80‐90 mm Hg diastolic (DBP) consuming 1 or 2 cups vegetable juice (n=15) there was a significant decrease in SBP, DBP and mean arterial pressure (p<0.05) over time. (Sponsorship: Funding provided in part from Campbell Soup Company).
Acute effects of weight lifting on plasma adiponectin in trained versus untrained individuals
Authors: Varady Krista A , Bhutani Surabhi , Church Emily C , Phillips Shane A
Published: June 2021

Adiponectin, an adipose‐derived hormone, exerts cardio‐protective effects. Short‐term resistance training augments adiponectin, which may confer protection against coronary heart disease (CHD). Whether these increases in adiponectin occur in response to acute resistance training is not yet known. Moreover, whether this effect varies between trained versus untrained individuals also remains unclear. Accordingly, we examined the effects of acute resistance training on plasma adiponectin levels in trained versus untrained men and women. Subjects (n = 35) were categorized into 4 groups: 1) sedentary, 2) weight lifters, 3) runners, or 4) weight lifter/runners. All subjects underwent a single progressive leg press weight lifting session. At baseline, adiponectin, age, BMI, and percent body fat were similar between groups. Plasma adiponectin increased by 29 ± 12% (P = 0.01) in the weight lifter/runners post training. There was a trend towards augmented adiponectin for sedentary subjects and weight lifters (20 ± 12%, P = 0.09 and 24 ± 14%, P = 0.10, respectively), but not for the runners (15 ± 13%, P = 0.77). There were no significant changes in HDL cholesterol or C‐reactive protein (CRP) concentrations post exercise. Changes in adiponectin were not correlated to changes in HDL cholesterol or CRP. Thus, adiponectin levels may be increased by acute resistance training in both untrained and trained individuals.
Effects of the Curves® fitness & weight loss program in women with medically‐managed conditions: body composition and resting energy expenditure
Authors: Rasmussen C , Culbertson J , Li R , Ferreira M , Parker A , Jitomir J , Galbreath M , Serra M , Beavers K , Dove J , Shelmadine B , Hudson G , Curts C , Moreillon J , Byrd M , Deike E , Kreider R
Published: June 2021

146 sedentary women (50±10 yrs, 162±6 cm; 95±20 kg; 46±5% body fat, 36±7 kg/m2) with medically‐managed conditions were assigned to an exercise & no diet group (E) or a low calorie high carbohydrate (HC) or high protein (HP) diet. Diets consisted of 1,200 kcal/d for 1‐wk and 1,600 kcal/d for 9 wks of either HC (55% C, 15% P, 30% F) or HP (15% C, 55% P, 30% F). During weeks 10‐14, subjects consumed a HC maintenance diet (2,600 kcals/d) and were instructed to diet for 2‐d at 1,200 kcals/d if they gain 3 lbs. Subjects participated in a supervised Curves fitness program 3‐d per wk. DEXA body composition and REE measurements were obtained at 0, 10, and 14 weeks and were analyzed by repeated measures ANOVA. Data are presented as means ± SD changes from baseline for the E, HC, and HP groups, respectively, after 10 and 14 weeks. Subjects in the HP group lost more weight (‐2.3±6.6, ‐2.9±7.3; ‐7.9±8.7, ‐8.3±9.8; ‐10.0±6.6, ‐10.6±7.8 lb, p=0.000) and fat mass (‐3.1±6.4, ‐3.4±6.7; ‐3.9±7.6, ‐4.0±7.6; ‐7.6±5.6, ‐8.3±6.8 lb, p=0.001). Subjects in the E group increased REE while subjects in the diet groups only slightly decrease REE (17.1±2.1, 18.0±3.0, 18.5±3.2; 17.3±1.8, 16.8±2.6, 16.5±2.3; 17.0±3.0, 16.4±2.8, 16.5±2.3 kcal/kg, p=0.001). Results indicate that the Curves program is effective to promote weight loss without marked reductions in REE in women with medically‐managed conditions.
Regulation of plasma endocannabinoids differs in pregnant versus non‐pregnant women
Authors: Durham Holiday , Wood JT , Williams JS , Judge MP , Makriyannis A , Lammi‐Keefe CJ
Published: June 2021

Endogenous cannabinoids, endocannabinoids, are lipid messengers and analogs of polyunsaturated fatty acids. The endocannabinoid metabolome is comprised of over a dozen metabolites associated with a variety of functions in central and peripheral physiology, reproduction and development. We quantified 15 plasma analytes of the endocannabinoid metabolome in pregnant women (n=34) at 20‐22 weeks versus non‐pregnant women (n=9) using liquid chromotography‐mass spectrometry. Ethanolamides were higher in pregnant versus non‐pregnant women (mean±SD): palmitoylethanolamine,; (5.32± 4.07 pg/ μl versus 1.98 ± 0.40 pg/ μl, p<0.01), oleoylethanolamine (3.08 ± 1.72 pg/ μl versus 1.37 ± 0.39 pg/ μl, p<0.01) and arachidonoylethanolamine (0.68 ± 0.22 pg/ μl versus 0.24 ± 0.10 pg/ μl, p < 0.01). The glycerols: 2‐arachidonolglyerol was significantly higher during pregnancy (133.17 ± 71.06 pg/ μl versus 9.96 ± 5.80 pg/ μl, p<0.01) while 2‐ oleoyglycerol was lower in pregnancy (472.01 ± 299.50 pg/ μl versus 1217.64 ± 466.35 pg/ μl, p<0.01); 2‐palmitoyglycerol was detected only in pregnancy (1850 ± 1254 pg/µl). In conclusion, pregnancy altered specific metabolites in the plasma endocannibinoid system.
Seasonal variation in vitamin D status in healthy young adults of different ancestry in the Toronto area
Authors: Gozdzik Agnes , Barta Jodi , Wu HongYu , Cole David , Vieth Reinhold , Whiting Susan , Parra Esteban
Published: June 2021

This study examined seasonal variation in serum 25(OH)D concentrations in young adults of different ancestry. 237 subjects participated in the study. Dietary intake, anthropometric measurements, skin pigmentation, UVR exposure and serum 25(OH)D levels were measured in late summer and winter in the Toronto area.

Mean late summer serum 25(OH)D concentration was 49.7 nmol/L for the full sample. However, concentrations were lower for those of East Asian and South Asian ancestry than those of European ancestry (44.6, 33.9 and 71.7 nmol/l, respectively). During late summer, serum 25(OH)D levels were influenced by skin pigmentation (p<0.001), vitamin D intake (p<0.001) and the amount of time spent outdoors at peak UVR hours (p=0.003).

Mean winter serum 25(OH)D concentration was 35.4 nmol/L. Again, mean concentrations were lower in those of East Asian and South Asian ancestry compared to those of European ancestry (28.1, 26.5 and 51.6 nmol/l, respectively). Total vitamin D intake (p<0.001) and summer serum 25(OH)D levels (p<0.001) had significant effects on wintertime vitamin D status.

The low 25(OH)D levels observed during the winter, and also during the late summer for many young adults is of public health concern. Our data indicates that vitamin D intake is insufficient to maintain adequate levels of vitamin D throughout the year, particularly in individuals of non‐European ancestry.

NSERC, ERA and Wenner‐Gren
The effect of systemic antioxidant supplementation on lung compartment antioxidants and systemic and lung‐specific F2‐isoprostane concentrations
Authors: Agler Anne Hermetet , O'Mahony Michael , O'Connor Timothy , Yeotsas Mary , Hackett Neil , Crystal Ronald , Cassano Patricia
Published: June 2021

Epidemiologic studies support the hypothesis that antioxidants decrease oxidant burden in lung tissue. A randomized double‐blind placebo‐controlled study of 20 participants investigated whether 30‐day supplementation with vitamins C (1000 mg/d) and E (400 mg/d), and selenomethionine (400 μg/d) affects systemic (plasma) and lung‐specific (bronchoalveolar lavage fluid, BAL) nutrient concentrations and a biomarker of oxidative stress (F2‐isoprostanes, F2s). Results for selenium (Se) and vitamin E (E) are presented; vitamin C assays are not completed. Supplementation increased plasma E and Se 72% (p<0.01), and 81% (p<0.0001). Supplementation did not affect BAL E, but BAL Se increased 40% (p=0.13). Pre‐post change in plasma was associated with pre‐post change in BAL for Se only (r=0.51, p=0.04). Supplements decreased plasma F2s 24% (vs. 13% decrease in placebo, p=0.40), but the participant with highest baseline F2s decreased 66%. Urine F2s decreased 14% in response to supplements (vs. 50% increase in placebo, p=0.05), and change in urine F2s was inversely associated with change in plasma E (r=‐0.34, p=0.23) and Se (r=‐0.47, p=0.09). Treatment had no effect on change in BAL F2s (p=0.94), but the assay had low reliability due to dilution of the analyte. The effect of intervention on oxidant stress varied by level of stress, by antioxidant, and by site (plasma or BAL); interventions need to consider all three.
Population attributable risk and population attributable risk percentage for high methylmalonic acid in the post‐folic acid fortification period in the US
Authors: Vanegas Sally M , Kafai Mohammad R , Ganji Vijay
Published: June 2021

Population attributable risk and population attributable risk percentage for methylmalonicacidemia in the post‐folic acid fortification period in the US

Serum methylmalonic acid (MMA) is a sensitive marker of cobalamin status. We investigated population attributable risk (PAR) and population attributable risk percentage (PAR%) for high serum MMA (>350 nmol/L) using the data from 3 cross‐sectional National Health and Nutrition Examination Survey cycles (1999‐2004) conducted in the post‐folic acid fortification period on US residents (n=18569). PAR%s for high MMA were 24.8% for non‐Hispanic white [prevalence, 3.4%; odds ratio (OR), 1.6; P<0.0001)], 40.5% for =60 y old persons (prevalence, 8.3%; OR, 4.0; P<0.0001), 11.8% for nonsupplement users (prevalence, 3.5%; OR, 1.82; P<0.0001), 13.3% for serum creatinine =130 ?mol/L (prevalence, 34.1%; OR, 12.6; P<0.0001), and 16.2% for serum cobalamin concentration <148 pmol/L (prevalence, 27.6%; OR, 13.5; P<0.0001). In the post‐folic acid fortification period, old age, white race, nonsupplement usage, kidney dysfunction, and cobalamin deficiency significantly contribute to PAR and PAR% of high MMA in the US. By improving serum cobalamin concentrations ³148 pmol/L, the incidence of high MMA would be reduced by »16%. This amounts to a reduction of 5 new cases per 1000 people (PAR=0.005) of high MMA in the US. This is an important finding in light of calls for cofortification of folic acid fortified cereals and cereal products with cobalamin.
Consumption of 100% Fruit Juice and Risk of Obesity and Metabolic Syndrome: Findings from the National Health and Nutrition Examination Survey 1999‐2004
Authors: Fulgoni Victor L , Pereira Mark A
Published: June 2021

Few studies have examined the association between 100% fruit juice consumption and obesity and related metabolic outcomes. Analysis of a multiethnic sample of U.S. adults (n=14,196) from the National Health and Nutrition Examination Survey (NHANES) 1999‐2004 examined the association between 100% fruit juice consumption and odds of obesity (body mass index (BMI) = 30 kg/m2) and metabolic syndrome (Adult Treatment Panel III definition). We used logistic regression analysis to estimate the odds of obesity and metabolic syndrome per fruit juice consumption exposure category, while adjusting for covariates that may be confounders of this association. Fruit juice intake was quantified as 'some' (n=3,961) or 'none' on the day of the 24‐hr dietary recall. Consumers of 100% fruit juice, relative to non‐consumers, had lower mean BMI, lower waist circumference, lower HOMA insulin resistance (p<.001). Level of intake (oz/day) had a linear inverse association with these parameters. Consumers relative to non‐consumers had 22% (95% CI = 13% to 30%) lower odds of obesity and 15% (95% CI = 10% to 28%) lower odds of metabolic syndrome. After adjustment for demographics and lifestyle factors, including physical activity, energy intake, and other dietary factors, the lower odds of obesity remained statistically significant, but there was no longer a statistically significant reduction in odds of metabolic syndrome. In conclusion, compared to non‐consumers, 100% fruit juice consumers were leaner, more insulin sensitive, and had lower odds of obesity and metabolic syndrome. The association with obesity remained after controlling for confounding lifestyle factors, while the association with metabolic syndrome was primarily explained by lifestyle factors. Supported by the Juice Products Association.
Association of the Slc30a8 rs13266634 polymorphism with type 2 diabetes and central obesity in a Cuban‐American population
Authors: Liuzzi Juan P , Masmouei Hoda , Zarini Gustavo G , Huffman Fatma G
Published: June 2021

Several genome‐wide association studies identified a strong association between the zinc transporter Slc30a8 rs13266634 polymorphism with type 2 diabetes (T2D) in individuals of European ancestry. We investigated the association of the Slc30a8 rs13266634 polymorphism (CC, TT and CT genotypes) with diabetes status and central obesity in Cuban‐Americans. Participants were randomly recruited from South Florida. The polymorphism was genotyped in 242 subjects (127 with and 115 without T2D) and 175 participants were classified as having central obesity. The polymorphism was significantly associated with central obesity (p=0.043). The post hoc analysis showed that this significant association was only true between CC and CT genotypes (p=0.012). No significant association was found between the polymorphism and diabetes status (p>0.05). Logistic regression analysis indicated that the odds of having central obesity were 2.11 times greater in subjects with the genotype CC than in participants with the CT genotype (OR= 2.11, 95% CI 1.1 to 3.8, p= 0.013).These results suggest a role of the Slc30a8 rs13266634 polymorphism in the development of central obesity. The lack of association between the polymorphism and diabetes status in this study could be attributed to the small sample size used. Supported by a grant from NIH/MBRS.
High fat diet alters expression of catechol‐O‐methyltransferase in the brains of mice and decreases motivation to obtain reward
Authors: Lavin Desiree Nicole , Sherry Christina L , Park Min Jung , O'Connor Jason , Dantzer Robert , Kelley Keith W , Freund Gregory G
Published: June 2021

Obesity is a harmful and costly condition which continues to increase in prevalence. Co‐morbidities accompanying this disease now include brain‐based disorders that impact cognition and mood. Illumina BeadChip Arrays performed on brains from high‐fat diet (HFD) and low‐fat diet (LFD) fed mice revealed a 60‐fold increase in prolactin mRNA expression in HFD mice. Real time PCR confirmed this increase as 1643‐fold. Since central DA inhibits prolactin secretion, the DA degradation enzyme catechol‐O‐methyl transferase (COMT) was examined by real time PCR and showed a 1000‐fold increase HFD mice brains as compared to LFD mice brains. Potentially linked to brain‐based DA loss are behavioral changes such as anhedonia and depression. Saccharin preference testing showed that HFD mice as compared to LFD mice exhibited saccharin aversion (25% vs 75% of total fluid consumption). In support, HFD mice also demonstrated a 2.3‐fold decrease in burrowing as compared to LFD mice. To probe the mechanism of these behavioral changes db/db mice (which lack a functional leptin receptor) were examined and found to have a preference for saccharin (93% vs 27% of total fluid consumption) and increased burrowing (4.5‐fold) when compared to HFD mice. Finally, brain based leptin mRNA expression was increased 3‐fold in HFD mice when compared to LFD mice. Taken together these findings suggest that leptin regulates reward motivation in HFD mice by impacting COMT expression and DA degradation.