bluuebunny/crossref_metadata_2025_split huggingface dataset:
Decreased expression of Cdc25a in breast stroma of diethylstilbestrol treated female ACI rats
Authors: Taylor LaShaundra , Newell Oneil , Darling‐Reed Selina , Soliman Karam , Hudson Alicia , Elie Yasmeen 
Published: June 2021

Diethylstilbestrol (DES), a known human carcinogen and synthetic nonsteroidal estrogen has been shown to cause pituitary, breast and cervix cancers. DES has been shown to produce mammary tumors and double strand breaks in rats and induce breast cancer in humans. Diallyl sulfide (DAS), a garlic organosulfur compound (OSC) has been shown to inhibit chemical carcinogenesis in animals. OSCs like DAS are known to decrease proliferation of cancer cells by delaying cell cycle progression. The effect of DAS on the proliferation of stroma breast tissue by DES is not fully elucidated. This study will determine the proliferative properties of DAS in breast stroma of DES induced female ACI rats by examining Cdc25a and ATM expression. Female ACI rats were treated for 6 months with corn oil (control), 10mg/kg DES and/or .01mg/g DAS. RNA was isolated from breast tissue using trizol and converted to cDNA using Stratagene first strand cDNA synthesis reaction. Gene expression profiles were determined using Super Array pathway finder and confirmed with real time RT‐PCR. Cdc25a and ATM expression in the DES treated group is decreased significantly compared to the control group. Cdc25a shows an increase in the fold change in the DES/DAS group as compared to the control. We conclude that the decreased Cdc25a expression in the DES treated group may induce cell cycle arrest while the co‐treated group is approaching the level of the control.Funded by RCMI Grant #2G12RR03020‐24
Diallyl Sulfide inhibits Diethystilbestrol induced Breast Tumor in Female ACI rats
Authors: Newell Oneil G , Taylor LaShaundra , Hudson Alicia , Darling‐Reed Selina , Reams Renee , Oriakiu Ebenezer , Reuben Jayne 
Published: June 2021

Previous studies in this lab have shown that diallyl sulfide (DAS) inhibits DNA adduct formation, lipid peroxidation and modulate detoxification and DNA repair genes and enzymes in breast tissue of diethylstilbesterol (DES) treated female ACI rats. These findings are important since estrogen and estrogenic compounds such as DES have been shown to induce breast cancer in humans and animals. In addition, scientists have postulated that DAS, a constituent of garlic, is an effective cancer prevention agent. In this study, we hypothesize that the release of inteleukin 6 by DES induced cancerous cells leads to activation of the JAK‐ Stat pathway which can increase cell proliferation and inhibit apoptosis. DAS may modulate these changes. To prove this hypothesis, 6 week old female ACI rats were implanted with Control (silicon implant alone) and DES (50mg/kg) silicon pellets were implanted s.c. In addition, these animals were fed normal chow or DAS (as co‐treatment) containing chow ad libitum for six months. At sacrifice, representative mammary tissueand all palpable mammary tumors were removed for genetic and histopathologicalanalysis. Genetic analysis was done by microarray analysis and validated using PCR array. Our data show significant increase in interleukin 6 gene expression in cancerous cells (DES group) and a significant decrease in the DAS co‐treatment group. Furthermore, a significant modulation of genes associated with the JAK/STAT pathway was observed. Animals co‐treated with DAS were free of tumor. For the first time our lab was able to show that DAS prevents DES induced breast tumors in female ACI rats.Funded by RCMI Grant #2G12RR03020‐24
Requirement for labile Zn2+ in phagocytosis by murine macrophages
Authors: Williams Miguel , Kohler Jonathan E , Blass Amy L , Lederer James A , Kelly Edward , Soybel David I 
Published: June 2021

IntroductionSystemic Zn2+ deficiency impairs the ability to fight infection. We hypothesized that one mechanism of immune dysfunction in the setting of Zn2+ deficiency is impaired phagocytosis by macrophages.MethodsRAW 264.7 murine macrophages were incubated for three hours with E. coli cell walls labeled with Vybrant and pHrodo fluorescent reporters. Co‐incubation occurred in the presence or absence of two intracellular Zn2+ chelators (high affinity TPEN 10μM, low affinity BAPTA 10μM) and one extracellular zinc chelator (DTPA 10 μM). Confirmatory experiments were performed with mouse peritoneal macrophages.ResultsIntracellular zinc chelators caused reduced phagocytosis vs control (TPEN: 28% ± 8; BAPTA 54% ± 14%, p < 0.02, N = 5). In contrast, chelation of extracellular zinc with DTPA had no effect.ConclusionFree cytoplasmic Zn2+ is required for effective internalization of extracellular bacterial particles by both cultured and primary murine macrophages. Under acute conditions, intracellular stores are sufficient to optimize function.
Beneficial effect of melatonin on improvements of neurological function in focal cerebral ischemia
Authors: Lee Seunghoon , Lee Sang‐kil , Chang Kyu‐tae , Hong Yonggeun 
Published: June 2021

Ischemic stroke involves oxidative damage caused by the cellular accumulation of calcium; thus, in the present study, we investigated the effect of neurological dysfunction on various markers related to anti‐oxidant and anti‐inflammatory processes in brain tissue obtained from focal cerebral ischemic rats, and we assessed the influence of long‐term melatonin treatment. Male Sprague‐Dawley rats (n=25, eight‐week‐old) were divided into five experimental groups: group‐A (untreated control), group‐B (vehicle, treated with 0.9% saline for eight weeks), and groups‐C through ‐E (MCAo‐induced focal cerebral ischemic rats treated subcutaneously with melatonin at 10 mg/kg/day at 07:00, 19:00, and 07:00 plus 19:00, respectively). After eight weeks of treatment, the rats were sacrificed by decapitation, and their brains collected for RNA isolation. The differential expression of such inflammation‐ and neurotrophic‐related genes as iNOS, nNOS, and BDNF was then examined. The expression of iNOS and nNOS was decreased in groups‐C and ‐E, as compared to that in the vehicle group, while expression of the neurotrophic factor BDNF was significantly increased in the melatonin‐treated groups. Our results indicate that melatonin decreases the expression of anti‐inflammatory and anti‐oxidant‐related genes.Funding: BioGreen21 Program (Code No. 20070401‐034‐006‐009‐02‐00), Rural Development Administration, Korea
Upregulation of adipogenesis induced by exogenous melatonin in vitro and in vivo
Authors: Kim Sunmi , Hong Yunkyung , Li Zichao , Hong Jeong‐wha , Hong Yonggeun 
Published: June 2021

Melatonin, a major product of the pineal gland, controls many biological systems on a roughly 24‐h cycle. The regulation of energy homeostasis, including adipogenesis, is one example of a circadian clock‐controlled pattern. Here, we investigated the putative role of melatonin in lipogenesis in vitro and vivo. Undifferentiated 3T3‐L1 preadipocytes were cultured and treated with melatonin. On day 1 or 60, exogenous melatonin was injected subcutaneously into Sprague‐Dawley rats at 07:00 and 19:00. The expression of several markers of lipid metabolism, including PPARγ, perilipin, and Hmgcr, was analyzed by RT‐PCR. Oil red O staining was used to detect lipid droplets in vitro. Morphological changes were observed in 3T3‐L1 cells exposed to exogenous melatonin in vitro. A significant increase in adipogenesis marker expression was detected over time (p<.05), and oil red O staining was observed in cells treated with 1 mM or 10 nM melatonin. Exogenous melatonin treatment for one day significantly decreased cardiac Hmgcr mRNA expression, whereas treatment for 60 days resulted in a definite reduction in hepatic expression (p<.05). Significant changes in Hmgcr, PPARγ, and perilipin mRNA expression were detected in response to melatonin; thus, melatonin regulates lipid metabolism through transcriptional regulation.Funding: BioGreen21 Program (Code No. 20070401‐034‐006‐009‐02‐00), Rural Development Administration, Korea
Increased contractile acitivity induces autophagy in skeletal muscle
Authors: Lira Vitor A. , Okutsu Mitsuharu , Zhang Mei , Yan Zhen 
Published: June 2021

Contractile activity is essential in maintaining and promoting the oxidative phenotype of fatigue resistance, metabolic flexibility, insulin sensitivity and resistance to oxidative stress in skeletal muscle. This requires constant remodeling of structural proteins and organelles (e.g. mitochondria). We therefore hypothesized that autophagy, a catabolic process involved in the degradation of long‐lived proteins and organelles, is enhanced by increased contractile activity (i.e. endurance exercise). We submitted adult mice (12‐wk old, C57BL6) to 28 days of voluntary wheel running and used sedentary mice as controls (n=10/group). The expression of proteins associated with autophagosome formation (Beclin 1, LC3‐I+LC3‐II), mitochondrial autophagy (Bnip3), and aggregate protein degradation (p62/SQSTM1) were measured in the exercise‐recruited plantaris muscles. Consistent with our hypothesis, exercise training resulted in significant induction of Beclin1 (33%), Bnip3 (41.5%), LC3‐I+LC3‐II (43%) and LC3‐II‐to‐LC3‐I ratio (210%), and reduction of p62 (24%). The same directional changes were observed when tonic, oxidative soleus muscles were compared with phasic, glycolytic white vastus muscles in sedentary mice. Our findings suggest a role for autophagy in contractile activity‐mediated maintenance and promotion of oxidative phenotype in skeletal muscle.This study was funded by NIH Grant AR050429 (Zhen Yan).
Down‐regulation of autophagy induced by caveolin‐3 and myosin heavy chain in response to forced exercise in rats
Authors: Park Sookyoung , Hong Yunkyung , Lee Youngjeon , Hong Yonggeun 
Published: June 2021

Although suppressing myostatin‐mediated signaling by caveolin‐3 (cav‐3) may results in reduction of muscular atrophy, the skeletal muscle phenotypic response following forced exercise is not fully defined. Therefore, we examined whether the changes of caveolins and myosin heavy chain (MHC) gene expression have relevance to autophagic signaling in forced exercised muscle. Male (n=16) and female (n=16) Wistar rats (10–12 weeks age, 280–300 g each) were divided into two groups: control (Con) and exercise (Ex). The rats in the Ex group were subjected to treadmill exercise at 25 m/min for 30 min, three times a day (07:00, 15:00, and 23:00). Stable expression of cav‐3 was detected in all tissues taken from the Ex group. In the gastrocnemius (GCM) muscle of the female rats, the expression of cav‐3 and MHC2a was significantly increased in the Ex group, as compared with the Con group (p<.05). Similarly, significantly greater MHC2x gene expression was detected in the GCM muscle of the male rats in the Ex group, as compared to the Con group (p<.05). Finally, increased cav‐3 gene expression and slightly decreased TGF‐β1 gene expression were noted in the muscles of the rats, suggesting that cav‐3 influences the expression of MHC isoforms and TGF‐β1. Furthermore, the conversion of LC3I to LC3II was significantly decreased in the GCM muscle of the male rats, indicating that protein degradation was reduced by forced exercise.Funding: BioGreen21 Program (Code No. 20070401‐034‐006‐009‐02‐00), Rural Development Administration, Korea
Sensitivity to low pH in mouse glomus type I cells correlates with ASIC3 expression
Authors: Lu Yongjun , Whiteis Carol A , Chapleau Mark W , Sluka Kathleen , Abboud Francois M 
Published: June 2021

We have recently reported that acid‐sensing ion channels (ASICs) are expressed in glomus cells of rat carotid bodies (CB) and that their activation at low extracellular pH results in rapid early depolarization which is inhibited by amiloride (Circ Res 101:109‐1019, 2007). Moreover, the ASIC mediated inward current and depolarization at low pH are enhanced in glomus cells of spontaneously hypertensive rat (SHR) which overexpress ASIC3 in their carotid bodies (Circ Res 105:536‐545, 2010). In this study we tested the hypothesis that ASIC3 contributes to responses to low pH in mouse carotid bodies (CBs). We contrasted calcium transients Δ[Ca2+]i during extracellular acidosis (pH 6.0) and cyanide (CN 1mM) in three groups of mice: ASIC3 null (KO), wild type (WT), and ASIC3 transgenic (Tg) mice. Clusters of glomus cells were dissociated from the carotid bodies, loaded with Fluo4/AM (a single wavelength Ca2+ probe), imaged with a CCD camera (Photometrics Cool SNAP‐cf) and analyzed with software (MetaMorph 6.1). Baseline values [Ca2+]i were 57±2, 56±3, and 55±5 nM in KO, WT and Tg respectively. The results shown below indicate that in KO there was a significant reduction in the percentage of cells responding to low pH compared to CN. The magnitude of the Ca2+ transients during low pH was significantly lower than during CN in KO mice but significantly higher in Tg mice (p < 0.01).

Low pH 6.0
CN (1mM)

KO
WT
Tg
KO
WT
Tg

Total cells
207
205
32
118
129
32

% responsive
41%†
75%
69%
71%
81%
59%

Δ[Ca2+]i nM
9±1*
10±1*
15±1†*
12±1
14±1
7±1

p < 0.05 (KO or Tg vs. WT);
p < 0.01 (pH6.0 vs. CN)

Contrasting responses to low pH to those with CN allowed us to confirm the specificity of the correlation between pH responsiveness and ASIC3 expression. The results indicate that ASIC3 is an important determinant of acid sensitivity in mouse carotid body chemoreceptors. (HL14388).
Bradycardic response induced by stimulation of α4β2 nicotinic receptors
Authors: Li Yi‐Fan , LaCroix Carly , Freeling Jessica 
Published: June 2021

Our recent studies revealed that, in a dual‐phase response induced by non‐selective nicotinic stimulation, the bradycardic phase of the response was blocked by a selective agonist to α4β2 nicotinic cholinergic receptors (nAchRs). This study was to further investigate the functional role of this subtype of nAchRs in regulation of heart rate. In urethane‐anesthetized male Swiss Webster mice, the intravenous injection of an α4β2 nAchRs agonist, varenicline, induced a quick and pronounced bradycardic response without sympathetic responses. This bradycardic response was prolonged after the administration of a cholinesterase inhibitor, neostigmine and eliminated by a muscarinic receptor antagonist, atropine, suggesting that this response is associated with acetylcholine (Ach) action and is mediated via muscarinic receptors. These data suggest that α4β2 nAchRs may be located in the intracardial ganglia where the receptors play a role in regulation of Ach release.This work was supported by American Heart Association grant No. 0835256N and NIH grant No. 1R03AG033291. Varenicline compound was provided by Pfizer Inc.
A structural model for catalysis by tyrosyl‐tRNA synthetase
Authors: First Eric Allen 
Published: June 2021

Twenty‐eight tyrosyl‐tRNA synthetase (TyrRS) structures were aligned and their active sites were compared. This analysis revealed that the HIGH signature sequence adopts two distinct conformations that correlate with the open and closed forms of the KMSKS loop. Based on this analysis, we propose a model in which the binding of ATP forces HIGH to adopt a closed conformation. This forces the KMSKS loop to adopt a closed, strained, conformation, bringing the KMSKS sequence into the active site and positioning it to interact with pyrophosphate in the TyrRS·[Tyr‐ATP]‡ transition state. Formation of the transition state results in cleavage of the scissile bond in ATP, releasing the KMSKS loop from the closed (strained) conformation. This mechanism provides a structural explanation for the observations that: (1) tyrosyl‐tRNA synthetase uses ATP‐binding energy to stabilize the transition state of the reaction and (2) deletion of the KMSKS sequence increases the binding affinity of the TyrRS·Tyr complex for ATP. Lastly, structural comparison of eukaryotic and archaeal tyrosyl‐tRNA synthetases revealed a ligand‐dependent conformational change that links the tyrosine binding site to the dimer interface, suggesting a possible model for the observation that tyrosyl‐tRNA synthetase displays half‐of‐the‐sites reactivity with respect to the binding of tyrosine.This research was funded NIH GM68070 and MDA 4268.
Chemoenzymatic synthesis of HIV‐1 V1V2 glycopeptide antigens for epitope characterization and neutralizing antibody detection (1004.4)
Authors: Amin Mohammed , Lomino Joseph , Wang Lai‐Xi 
Published: June 2021

Recent discovery of a new class of glycan‐dependent broadly neutralizing antibodies (bnAbs), including PG9, PG16, and the PGT series antibodies, provides valuable templates for HIV‐1 vaccine design. Epitope mapping suggests that PG9 and PG16 recognize unique glycopeptide antigens located in the V1V2 region of gp120. However, further characterization of the neutralizing epitopes has been difficult due to the glycosylation heterogeneity of gp120. In this paper, we report the design, synthesis, and antigenicity of well‐defined V1V2 glycopeptides aiming to characterize the glycan specificity of the epitopes. Homogeneous V1V2 glycopeptides carrying defined N‐glycans at the glycosylation sites (N160 and N156 or N173) were synthesized by a convergent chemoenzymatic approach. Binding studies confirmed the essence of a Man5GlcNAc2 glycan at Asn160 for recognition by PG9 and PG16 and further revealed a critical role of a sialylated N‐glycan at the secondary site (N156 or N173) in the context of glycopeptides. We have also synthesized novel V1V2 glycopeptides in which the innermost GlcNAc was replaced with a Glc moiety. Binding studies show that the Glc replacement did not impair antibody recognition. The usefulness of the synthetic V1V2 glycopeptides as coating antigens for neutralizing antibody detection was demonstrated in an ELISA format, which enables the detection of PG9 and PG16 at up to 50 pM concentration. The high‐affinity synthetic glycopeptides identified also provides a basis for HIV‐1 vaccine design.Grant Funding Source: Supported by NIH Grant 1R21AI101035 to L‐XW
Analysis of the expression of eNOS in erythrocytes under hypoxic conditions (1013.15)
Authors: Nava Pérez Tania , Estrada José , Contreras Irazú , Moreno‐Altamirano Bertha , Pliego‐Rivero Francisco 
Published: June 2021

Background: Congenital heart diseases are among the most common birth defects, being the second leading cause of infant death in Mexico. Some of these pathologies are characterized by low concentrations of O2 in the blood, resulting in cyanosis. There is evidence that erythrocytes express active and functional eNOS, which catalyzes the production of nitric oxide (NO). NO activity in erythrocytes appears to include the regulation of membrane deformability and inhibition of platelet activation; however, the activities of eNOS, NO export to the vasculature and the relative contribution of erythrocytes to the active NO pool in circulation, have not yet been explored in detail.Objective: To identify differences in eNOS expression and activity in erythrocytes from children with congenital heart disease and cyanosis, compared to healthy controls.Methods: Analysis of eNOS expression and activity by western blot and fluorometry, in erythrocytes of patients diagnosed with congenital heart disease and blood O2 saturation below 80%, at the Children's Hospital‐IMIEM, Toluca, Mexico.Results: 30 samples from patients with congenital heart disease and blood O2 saturation less than 80%, and 6 samples from healthy controls matched for age and sex, have been collected. Erythrocytes of all samples have been isolated and changes in eNOS expression are being analyzed. Enzymatic activity is being analyzed by subjecting the erythrocytes to mechanical stress and by measuring changes in intracellular calcium concentrations and NO production.
p54nrb/NONO regulates cAMP signaling and cortisol production by modulating phosphodiesterase splicing (1013.21)
Authors: Yang Jia , Sewer Marion 
Published: June 2021

Phosphodiesterases (PDEs) play an integral role in modulating cellular signaling by degrading the second messenger cAMP. Mammalian PDEs are encoded by 21 different genes and are subdivided into 11 families (PDE1‐11), with more than 80 alternative splice variants generated from multiple promoters. We have shown previously that p54nrb/NONO is required for glucocorticoid biosynthesis, however the molecular mechanism by which p54nrb/NONO confers optimal cortisol production was unclear. We find that silencing p54nrb/NONO in H295R human adrenocortical cells abrogates adrenocorticotrophin (ACTH)‐stimulated cAMP production. Interestingly, the expression of multiple PDE isoforms, including PDE2, PDE3, PDE4, and PDE11 were induced in p54nrb/NONO knockdown cells. Analysis of PDE splice variants revealed that p54nrb/NONO plays a critical role in regulating PDE splicing. Additionally, whole transcriptome analysis identified that silencing p54nrb/NONO altered the splicing of multiple genes in adrenocortical cells, including cAMP responsive element binding protein 5 (CREB5), and histone deacetylase 9 (HDAC9). Collectively, our findings demonstrate that p54nrb/NONO plays a key role in regulating the capacity for cAMP signaling by controlling PDE splicing and expression, ultimately influencing glucocorticoid biosynthesis.Grant Funding Source: Supported by NIH GM073241.
Household food insecurity is associated with childhood stunting in vulnerable populations in Lebanon (1014.3)
Authors: Ghattas Hala , Sahyoun Nadine , Sassine AnnieBelle , Barbour Jessica , Seyfert Karin , Hwalla Nahla , Nord Mark 
Published: June 2021

Household food insecurity (HFI) has been shown to be an independent predictor of poor child nutritional status in various settings. In the Middle East region, no data exist on the effect of directly measured HFI on children’s nutritional outcomes. Using data from three household surveys of at‐risk communities in Lebanon, we examined the effect of HFI on nutritional status of children aged 6‐59 months (n=355) living in such communities. Food security was assessed using a 6‐item validated food security survey module. We found significantly higher rates of stunting in severely food insecure households (SFI) (23.4%) than food secure (4.9%) and moderately food insecure households (6.1%). After adjusting for age, gender and socio‐economic status, severe food insecurity remained an independent predictor of stunting (OR=3.74, p=0.002). Prevalence of overweight was also higher in the SFI, but this difference did not reach statistical significance. In the context of the advancing nutrition transition in Lebanon and other Middle Eastern countries, the results of this study indicate the need to explore and address the underlying causes of household food insecurity. This could contribute to reducing risk of childhood stunting, and its potential long term consequences on child health and development.Grant Funding Source: Supported by the American University of Beirut, the Heinrich Boll Foundation and UNHCR.