bluuebunny/crossref_metadata_2025_split huggingface dataset:
Melatonin is up‐regulator on small G‐protein mediated apoptotic cell death in cervical and endometrial cancer cells of human
Authors: Hong Yonggeun , Won Jinyoung , Park Kanghee 
Published: June 2021

Many gynecologic tumors are associated with infertility and spontaneous abortion that constitute a public problem. Recent studies have shown the main hormone of the pineal gland inhibit directly many different types of human tumor cells and naturally secreted cytotoxin, which induces tumor cell death(apoptosis). Additionally, activated Ras proteins have important roles on the regulation of apoptosis depending on cell type and other factors. Ras protein, a small GTP binding protein, send growth stimulating message to the nucleus through downstream small G protein such as Rac1 and Cdc42. Ras protein is an initiator of many tumors, and melatonin shows oncostatic action in various tumors cells. Whether melatonin can counteract the Ras‐involved functions remains unknown and is worth exploring. Thus, our overall hypothesis is that natural hormone melatonin regulates small GTP binding protein mediated apoptosis and we would demonstrate anti‐tumor function of melatonin in primary cultured human uterus cervix and endometrial cancer cells. What Ras gene transfected into cells were treated with melatonin, then observed increasing caspase‐3 expression suggesting turn of the apoptotic signal machinery. At physiological concentration of melatonin (1 nM), cell proliferation was decreased, suggesting cell cycle arrest through increasing p21 expression, which is mediated by p53(tumor suppressor gene). These observations indicate that melatonin, an endogenous hormone, inhibits the tumor cell proliferation suggesting melatonin should be developed as a therapeutic reagent.Supported by BioGreen21 Program (#20070401034006) of Rural Development Administration, South Korea
ERK Inhibition by SU1498 Alters Expression of Bcl‐2 Family Proteins in Breast Cancer Cells
Authors: Kovala Tom , Poulin Josee 
Published: June 2021

The extracellular signal‐regulated kinase (ERK) pathway is vital to the cell survival. We have demonstrated the ability of SU1498, an inhibitor of ERK kinase activity, to sensitize breast cancer cells with constitutively active ERK to apoptosis. To identify the mechanisms involve, the expression of the antiapoptotic Bcl‐2 and Bcl‐xL and the proapoptotic Bad, Bax, Bik and Bak were examined under apoptotic conditions. One breast cell line (MCF‐10A) and three breast cancer cell lines (MCF 7, MDA‐MB‐231 and MDA‐MB‐468) were used to examine the effects of SU1498 and serum starvation on the expression of the Bcl‐2 family proteins. The MCF‐10A and MCF7 cells exhibit normal ERK regulation while the MDA‐MB‐231 and MDA‐MB‐468 cells lines have a constitutively activated ERK. Across all the cell lines, the combined treatments resulted in either decreased expression, or no changes in the expression, of the antiapoptotic Bcl2 proteins. The expression of the proapoptotic proteins Bad or Bak were dramatically upregulated only in those cells with constitutive ERK activation, while they tended to demonstrate reduced expression in the cells lines with normal ERK regulation. These cell lines with upregulate Bad and/or Bak expression were also those most sensitive to SU1498 induced cell death. The ability of SU1498 to sensitize breast cancer cells to apoptosis by inhibition of ERK may have therapeutic uses.Supported by NSERC
The macronutrient composition of the evening meal before glycemic index testing has no effect on glycemic response
Authors: Brown Rachel Clare , Ning Boris , Williams Sheila , Venn Bernard , Green Tim John 
Published: June 2021

BackgroundA criticism of glycemic index (GI) is the large variation in glycemic response, both between and within individuals. To reduce this variation it is recommended that GI testing of a food be conducted under standardized conditions. One recommendation is that each subject consumes the same evening meal before each test day. Given the demands placed on participants it is important to assess whether such a restriction is necessary.AimTo determine whether manipulating the fat and carbohydrate content of the evening meal preceding GI testing has an effect on glycemic response.MethodsUsing a randomized crossover design, 20 participants completed a series of 8 tests. Test foods consisted of 2 glucose beverages and 2 bread samples, containing 50g of available carbohydrate. Each test food was consumed following a high carbohydrate or a high fat meal the night preceding testing. Blood glucose concentration was measured at regular intervals over 2 hours and area under the curve (AUC) determined.ResultsThere were no significant differences in the AUC for the glucose drink [ratio (95% CI); 0.91 (0.80, 1.03)] or bread [1.15; (0.97, 1.36)] with the high carbohydrate and the high fat evening meal.ConclusionThe fat and carbohydrate content of the evening meal prior to GI testing does not influence blood glucose response, thus participants should be allowed some flexibility in evening meal selection.
Urine volume increases and urine specific gravity decreases in cats with nephrolithiasis or urolithiasis
Authors: Yu Shiguang , Burris Patricia 
Published: June 2021

The etiology of urinary tract stones in cats is not clear. Among others, concentrated urine is considered a risk factor. The objective of this study was to compare urine measurements in stone‐forming cats with those in healthy cats.Four cats with kidney (3 cats) or urinary bladder (1 cat) stones and 11 healthy cats were used. Stone‐forming cats were 6 to15 years old (median = 12.7 years) and healthy cats were 5 to 13 years old (median = 10.8 years). The stone‐forming cats were confirmed with x‐ray radiography and/or ultrasonography.Cats were fed a commercial dry cat food for 4 weeks. Forty‐eight hour urine was collected during the last two days of the study. The urine was collected continuously in the collection receptacles kept at 38 °C.Comparing with healthy cats, stone‐forming cats had significantly increased urine volume (87 ml/day vs. 145 ml/day, p < 0.05) and decreased urine specific gravity (1.033 vs. 1.025, p < 0.05). Urine pH was similar between the groups (5.94 vs. 5.88, p = 0.604). Urinary NH4+, Na, K, P, and Oxalate were significantly lower in stone‐forming cats (p < 0.05). Urinary Cl, Ca, Mg, S, and Citrate were similar between the groups (p > 0.05). These data show that urine was not concentrated in cats with existing stones in the urinary tract. The mechanism underling the increased urine volume and decreased urine specific gravity in stone‐forming cats is unclear and needs further investigation.
The Liver X‐Receptor (LXR) gene promoter is hypermethylated in a mouse model of prenatal protein restriction
Authors: Plosch Torsten , van Straten Esther M.E. , Bloks Vincent W. , Huijkman Nicolette C.A. , Kuipers Folkert 
Published: June 2021

Prenatal nutrition, e.g., nutritional status of the mother, has been epidemiologically identified as a determinant of adult disease. Feeding low‐protein diets during pregnancy in rodents is a well‐established model to induce "programming" events in offspring. We hypothesized that protein restriction would induce epigenetic adaptations which would interfere with lipid metabolism. C57BL/6 mice were fed a protein restricted diet during pregnancy. At day 19.5 of pregnancy, dams and fetuses were sacrificed. CpG island methylation microarrays were performed on fetal liver DNA. 204 promoter regions were differentially methylated upon protein restriction. The liver X‐receptor (Lxr) alpha promoter was hypermethylated in protein‐restricted pups. Lxr alpha is a nuclear receptor critically involved in control of lipid metabolism. mRNA level of Lxra tended to be reduced in fetal liver upon maternal protein restriction, whereas expression of Lxr target genes were significantly reduced. In vitro methylation of a mouse Lxra‐promoter/luciferase expression cassette resulted in a 24‐fold transcriptional repression. Our study demonstrates that, in mice, protein restriction during pregnancy interferes with DNA methylation in fetal liver. Lxra is a target of differential methylation and Lxra transcription is dependent on DNA methylation. We suggest that prenatal nutrition may influence adult lipid metabolism by DNA methylation which may contribute to the epidemiological relation between prenatal/neonatal nutrition and adult disease.Supported by the Dutch Heart Foundation (2004T048).
MTHFR C677T genotype and choline intake affect choline dynamics in Mexican American men
Authors: Caudill Marie A , Yan Jian , Wang Wei , Gregory Jesse F 
Published: June 2021

As part of a 12 wk controlled feeding study conducted in Mexican American men, stable isotope methodology was employed to assess the influence of choline intake and MTHFR C677T genotype on choline flux. Beginning wk 10, Mexican American men (15 677TT, 8 677CC) consumed 15% of either 550 or 1100 mg/d choline as D9‐choline. Liquid chromatography (or gas chromatography) mass spectrometry was used to measure the isotopic enrichment of choline and relevant metabolites in urine and blood (on‐going) obtained at wk 12. In urine, the enrichment of D6‐dimethylglycine to D9‐choline was greater (P<0.05) in men with the MTHFR 677TT vs CC genotype. In addition, enrichment of betaine was greater (P<0.05) in the 1100 vs the 550 mg/d choline intake group. These initial results suggest that choline flux through the betaine N‐methyltransferase pathway is greater in men with the MTHFR 677TT genotype relative to those with 677CC genotype under the conditions of this study. Further, oxidation of choline to betaine appears to be enhanced when choline intake is increased.Supported by the National Institutes of Health grant S06GM53933 and funds from the California Agricultural Research Initiative.
Effect of non‐oil seed pulses on glycemic control: A meta‐analysis of randomized controlled trials in humans.
Authors: Sievenpiper John , Esfahani Amin , Wong Julia , Carleton Amanda , Jiang Henry , Bazinet Richard , Jenkins David , Kendall Cyril 
Published: June 2021

BackgroundDietary pulses (beans, lentils, chickpeas, etc.) are a good source of viscous fibre and a valuable means for lowering the glycemic‐index (GI) of the diet.ObjectiveTo assess the effect of pulses on glycemic control, we conducted a meta‐analysis of experimental trials investigating the effect of pulses alone or in low‐GI or high‐fibre diets on indices of glycemic control.MethodsWe searched MEDLINE, EMBASE, CINAHL, and Cochrane Library for relevant controlled trials of ≥7d in humans. Two independent reviewers extracted information on study design, participants, treatments, and outcomes. Generic inverse variance models were used for pooled analyses. Heterogeneity was assessed by Chi2 and quantified by I2.ResultsForty‐four trials were included. Pulses alone (12 trials) lowered fasting blood glucose (FBG) (standardized mean difference [SMD] ‐0.81 [95% CI ‐1.32,‐0.29]) and insulin (‐0.61[‐1.07,‐0.14]). Pulses in low‐GI‐diets (19 trials) lowered glycosylated proteins (GPs) (‐0.28[‐0.42, ‐0.14]). Pulses in high‐fibre diets (12 trials) lowered FBG (‐0.22[‐0.43,‐0.00]) and GPs (‐0.33[‐0.59,‐0.06]). Inter‐study heterogeneity was significant in all cases.ConclusionsThese data demonstrate that pulses alone or in low‐GI or high‐fibre diets improve markers of glycemic control in humans. Subgroup analyses are planned to explore sources of heterogeneity.
Mitochondrial membrane potential regulates production of reactive oxygen species and opening of mitochondrial permeability transition pore
Authors: Sedlic Filip , Wakatsuki Tetsuro , Pravdic Danijel , Bosnjak Zeljko 
Published: June 2021

Anesthetic preconditioning (APC) protects the heart from ischemia/reperfusion injury. We hypothesized that APC by isoflurane protects the heart by attenuating generation of reactive oxygen species (ROS) that delays opening of mitochondrial permeability transition pore (mPTP) via mild decrease in mitochondrial membrane potential (Δψm). ROS and Δψm were measured in rat cardiomyocytes by real‐time confocal microscopy using TMRE and CM‐H2DCFDA fluorescent dyes, respectively. Opening of mPTP, which initiates cell death, was detected as rapid and complete loss of TMRE fluorescence from mitochondria. APC by isoflurane (0.5 mM) decreased TMRE fluorescence (88±5% of control) and increased flavoprotein fluorescence (109±3% of control), indicating decrease in Δψm and mitochondrial uncoupling, respectively. Low dose of protonophore DNP (100 nM) produced similar effect. Pyruvate (25 μM) increased respiration and reversed mitochondrial depolarization and uncoupling. When exposed to oxidative stress, myocytes with partly decreased Δψm produced less ROS (62±5% of control) and exhibited a delay in mPTP opening (162±7% of control). Increase in Δψm by pyruvate increased production of ROS and shortened the time of mPTP opening. In conclusion, APC protects cardiomyocytes in part via mild decrease in Δψm that attenuates ROS production under stress and leads to the delay in mPTP opening.Supported by P01GM066730
Biophysical characterization of Gβγ “hot spot” binding small molecules: explaining Gβγ “hot spot” binding effector selectivity
Authors: Seneviratne Pramodh , Wedekind Joseph , Burroughs Michael , Smrcka Alan 
Published: June 2021

Guanine nucleotide exchange proteins (G proteins) are heterotrimeric proteins composed of three subunitsα, β, γthat initiate intracellular signaling cascades. Previously our laboratory identified small molecules that bind to a protein‐protein interaction "hot spot" to achieve selective modulation of downstream effectors. We hypothesized that different compounds bind directly to different sub‐surfaces of the Gβγ 'hot spot'. To assess binding of compounds directly to Gβγ we developed a Surface Plasmon Resonance (SPR) method utilizing immobilized Gβγ subunits. The results indicate that multiple compounds bind directly to Gβγ with affinities in the range of 400 nM to 3μM. For example: the Kd for binding of Gallein to Gβ1γ2 was 420 nM with kon=1 x 103 M−1s−1, koff= 4 x 10−4 s−1. We separately purified Gβγ subunits with single amino acids within the Gβγ hotspot mutated to alanine and have obtained unique binding maps for 3 small molecules using SPR. To corroborate our SPR binding maps we also carried out binding experiments using 3H labeled Gallein. We are also in the process of obtaining co‐crystals of compounds bound to Gβγ, and solving their 3D structures using x‐ray crystallography. Understanding how selective small molecules interact with Gβγ will be important for determining the mechanism of action of these compounds and developing more potent and selective agents.This work was funded by (NIH GMRO1‐081772)
The tobacco smoke constituent, norharmane enhances nicotine self‐administration in an age‐dependent manner
Authors: Arnold Monica Martin , Prenger Jacque A , Belluzzi James D 
Published: June 2021

Smoking is the most preventable cause of death in the United States. Twenty‐one percent of U.S. adults consider themselves smokers with most beginning when they were teenagers. Although numerous smokers report the desire to stop, quit rates are low and current cessation aides are minimally effective. Animal models created to study smoking generally only use nicotine, the main psychoactive component of smoke; however experimental results do not reflect the addictiveness of cigarettes. This discrepancy may be because adult animals are used whereas initiation begins in adolescence, a critical time of brain development. Moreover, only nicotine is used despite that there are over 4000 constituents found in cigarette smoke. Therefore, the present study investigated how the age of acquisition and the tobacco constituent, norharmane, may influence nicotine self‐administration in adult and adolescent male rats. The co‐administration of nicotine (7.5 µg/kg/inj) and norharmane (0.1‐2.5 µg/kg/inj) at doses equivalent to what is found in the plasma of smokers after smoking one cigarette enhanced nicotine self‐administration in naïve adults compared to nicotine alone. Adolescents were insensitive to any of the drug combinations and responded minimally overall. Consequently, we have found that there is an age‐dependent sensitivity in responding for nicotine alone and in combination with norharmane.Sponsored by NIH DA 21267 & 19138.
CM156, A Sigma (σ) Receptor Antagonist, Mitigates Stimulant And Neurotoxic Effects Of Methamphetamine In Mice
Authors: Kaushal Nidhi , Seminerio Michael J. , Shaikh Jamaluddin , Medina Mark A. , McCurdy Christopher R. , Matsumoto Rae R. 
Published: June 2021

Methamphetamine (METH) is a psychostimulant drug of abuse, causing hyperthermia and neurotoxicity at high doses. Currently, there is no clinically proven pharmacotherapy to treat these effects. Therefore, there is a need to identify potential therapeutic targets. Radioligand binding assays showed that METH binds to sigma (σ) receptors in the brain. Antisense oligonucleotides targeting σ1 receptors antagonized the locomotor stimulant effects of METH in mice. As a potential pharmacological antagonist, CM156 was developed with high affinity and selectivity for σreceptors. CM156 antagonized the locomotor stimulant effects of METH without altering basal activity. CM156 was further tested against METH‐induced neurotoxicity, whereby male Swiss Webster mice were treated every 2 hours, a total of 4 times, with one of the following: Saline/Saline, Saline/METH (1.25‐10 mg/kg), CM156 (5‐20 mg/kg)/Saline, and CM156 (5‐20 mg/kg)/METH (5‐10 mg/kg). Body temperature was measured 1 hour after every treatment and the brains were collected for ELISA and immunohistochemical analyses one week later. CM156 significantly and dose dependently attenuated the METH‐induced hyperthermia, depletions in striatal dopamine and serotonin levels, and reductions in DAT levels, without itself causing any changes. Together, the data suggest that σreceptors represent a viable therapeutic target for mitigating METH effects.(Support: DA023205, DA013978)
An economic analysis of alcoholic and nonalcoholic beer drinking in rats exposed to daily restraint stress or handling
Authors: Kohut Stephen J , Christensen Chesley J , Riley Anthony L 
Published: June 2021

Using a behavioral economic approach, this study attempted to determine whether the reinforcing strength of alcoholic or nonalcoholic beer changes after stress or handling. Twenty‐four, male Wistar rats were trained to bar press for either alcoholic or nonalcoholic beer and assigned to one of four treatment groups: stress‐alcohol (SA), no stress‐alcohol (NA), stress‐no alcohol (SN) and no stress‐no alcohol (NN). The stressed condition consisted of 15 min of restraint stress, while non‐stressed rats were handled and placed into a novel cage for 15 min immediately prior to the session. After training under an FR1 schedule, the schedule was increased every five sessions from 3 to 32 in logarithmic steps. Consumption was plotted as a function of ratio size and modeled by the exponential‐demand equation (Hursh & Silberberg 2008). Consumption prior to the stress/handling manipulation was greater for nonalcoholic than alcoholic beer, but there was no difference between stressed and unstressed rats for either solution. When stress was applied, alcohol consumption decreased relative to that in the non‐stressed rats. Stress did not have an effect on non‐alcoholic drinking. The economic analysis showed that NA, SN and NN groups all defended beer consumption with greater vigor than the SA group. Our results suggest that stress has a suppressive effect on alcohol drinking in "naïve" rats.This work was supported by the Mellon Foundation.
Changes in tubular fluid pH and nucleotide concentration alter P2 receptor‐mediated regulation of renal ENaC
Authors: Wildman Scott S.P. 
Published: June 2021

Epithelial Na channels (ENaC) control Na reabsorption along the renal collecting duct (CD) and help determine systemic BP. We have shown that ENaC activity is inhibited by activation of apical P2Y2 and/or 4 receptors and P2X4 and/or 4/6 receptors when luminal concentrations of Na are high, and that apical P2X4 and/or 4/6 receptors switch to being potentiators of ENaC activity when concentrations of Na are lowered. Here we address the effect of altering luminal pH, and concentration of P2 receptor (P2R) agonists, on P2R‐mediated regulation of ENaC in the CD.Rats were maintained on a low Na diet to increase ENaC expression. Kidneys were microdissected, and CD split‐open to expose the apical membrane of cells for patch clamp experiments.When concentrations of P2R agonists were high, UTP‐evoked currents (i.e. P2Y2 and/or 4‐mediated) reduced, and 2meSATP‐evoked currents (i.e. P2X4 and/or 4/6‐mediated) increased, the amplitude of subsequent ENaC‐mediated currents. Lowering pH from 7.4 to 6.5 did not alter these effects. Further acidification to pH 5.5 increased the degree of inhibition by UTP and abolished the effects of 2meSATP‐evoked currents. At pH 7.4 and 6.5, when concentrations of P2R agonists were lowered, the inhibitory effect of UTP was abolished and the potentiating effect of 2meSATP was unaltered.Apical P2R and ENaC interactions in CD are complex and dependent on luminal Na and nucleotide concentration, and pH.
SPARC deficiency ameliorates renal damage resulting from angiotensin II and a high salt diet
Authors: Socha Matthew John , Manhiani Marlina , Motamed Kouros , Imig John D , Inscho Edward W 
Published: June 2021

Markedly elevated levels of matricellular protein SPARC (Secreted Protein Acidic and Rich in Cysteine, SP) have been found in serum of patients with fibrotic renal injury and in glomeruli of hypertensive injury. Our previous data indicate that SPARC deficiency resulted in decreased renal fibrosis, oxidative stress, and inflammation following Angiotensin II (Ang II)‐induced hypertension, with no improvement in renal function. We hypothesized that SPARC deficiency would attenuate the detrimental renal effects and protect kidney function in Ang II‐induced hypertension combined with a high salt diet. Following a 2‐week Ang II infusion combined with a high salt diet (4% w/v), and independent of blood pressure differences (SP+/+ 163 ± 4, SP−/− 162 ± 3 mmHg), SP−/− mice showed significant attenuations in albuminuria (urinary albumin decreased 70.7%), renal matrix deposition (urinary levels of active TGF‐β1 decreased 58.9%), reactive oxygen species formation (urinary 8‐isoprostane decreased 60.9%), and renal inflammatory responses (MCP‐1 and IL‐1β levels decreased 36.8% and 59.8%, respectively), relative to SP+/+ controls. We conclude that in a severe model of hypertension, SPARC deficiency protects against renal hypertensive damage at the cellular and functional levels.This work is supported in part by National Institute of Health grants K01‐CA089689 (to K.M.) and HL59699 (to J.D.I.).