bluuebunny/crossref_metadata_2025_split huggingface dataset:
Epigenetic Alterations caused by Decreased Cellular Methylation Potential Induce Fas‐FasL‐mediated Apoptotic Death in Leukemic T Lymphocytes
Authors: Patil Madhuvanti , Ghare Smita , Gobejishvili Leila , Joshi-Barve Swati , McClain Craig , Barve Shirish 
Published: June 2021

The transmethylation (TM) pathway is up regulated in proliferating T cells and transformed T leukemic cells but not in resting T cells, making it an ideal target to eliminate leukemic T cells. The TM pathway involves methyltransferase‐mediated conversion of S‐adenosylmethionine (SAM) to S‐adenosylhomocysteine (SAH). SAH is a potent feedback inhibitor of methyltransferases and is hydrolyzed by S‐adenosylhomocysteine hydrolase (SAHH), which determines the SAM: SAH ratio, known as the cellular methylation potential.The role of cellular methylation potential in the regulation of cell death in T leukemic cell lines was examined by inhibiting SAHH using pharmacologic SAHH inhibitors and RNAi. We demonstrate that a decrease in cellular methylation potential induces apoptosis in leukemic T lymphocytes. SAHH inhibitor treatment increases expression of FasL protein and activates the Fas‐FasL signaling pathway. Additionally, we observed an up regulation of FasL mRNA expression in leukemic T cells. ChIP analysis of histone H3 modifications at the FasL promoter showed increased transcriptional activation marks, namely acetylation at lysine 9 and 14, trimethylation at lysine 4 and increased recruitment of RNA Polymerase II. Overall, the data indicate the mechanistic role of cellular methylation potential in transcriptional regulation of FasL gene resulting in enhanced leukemic T cell death.
The Human Host Defense Peptide LL‐37 Induces Caspaseindependent Apoptosis Via Apoptosis‐Inducing Factor And Endonuclease G in Colon Cancer Cells
Authors: Ren Shunxiang , Cho Chi Hin 
Published: June 2021

LL‐37, a human host defense peptide, plays pivotal roles in diverse biological processes, including natural immunity, inflammation and tissue repair. However, the function of this peptide in tumorigenesis remains unclear. In this study, the effect of LL‐37 on human colon cancer HCT116 cells was characterized. LL‐37 induced extensive DNA fragmentation, chromatin condensation and phosphatidylserine externalization without causing caspase activation. Moreover, these effects were not blocked by caspase inhibitors. LL‐37 induced apoptosis via downregulation of Bcl‐2 and upregulation of Bak and Bax in a p53‐dependent manner. In this connection, the pro‐apoptotic effect of LL‐37 was reversed by Bcl‐2 overexpression, genetic ablation of Bax, or p53 siRNA. LL‐ 37 also induced the upregulation and nuclear translocation of apoptosis‐inducing factor (AIF) and endonuclease G (EndoG). Knocking down of these genes by siRNAs rendered the cells resistant to LL‐37‐induced apoptosis. Above all, the pro‐apoptotic effect of LL‐37 was found to be mediated through a pertussis toxin‐sensitive Gi‐coupled receptor. Taken together, we demonstrated that LL‐37 induced caspase‐independent apoptosis via the p53‐Bcl‐2/Bak/Bax and AIF/EndoG pathways. These findings open up a novel therapeutic avenue using LL‐37 for the treatment of colon cancer.Grant support: Research Fund for the Control of Infectious Diseases, Food and Health Bureau, Hong Kong, China.
Influence of Zedoary Oil on Cell Cycle and Cathepsin K Expression in A549 Cell Line in vitro
Authors: Yang Changfu , Niu Jianzhao , Li yadong , Wang Xiaobo , Huang Chunfang , Tang Binghua , Zhao Peiwen , Wang Jifeng 
Published: June 2021

ObjectiveTo explore the inhibiting effects of Zedoary oil on the proliferation and cathepsin K expression in A549 cell line in culture.MethodThe proliferation of lung adenocarcinoma cell line A549 were determined by MTT assay. The cells cyclic retardation were examined by using flowcytometry. Cathepsin K expression of level were detected by using western blot.ResultMTT showed that Zedoary oil had an inhibitory effect on the proliferation of A549 cells in 60~200 mg •L‐1. Flow cytometry indicated that Zedoary oil increased the percentage of G0/G1 phase cells and reduced the percentage of S phase cells. The results of western blot showed that the expression of cathepsin K was up‐regulated significangly in A549 cells in Zedoary oil groups compared with that in controls.ConclusionZedoary oil can significantly inhibit the growth of A549 cells, blocking the cell cycle. The effects may due to the up‐regulation of cathepsin K. This work was supported by founds:2008DFA31970 and the 111 project B07007 of China. Dr. Niu Jianzhao is the responsibility author.
The functional role of bestrophins and TMEM16A in rat mesenteric small arteries
Authors: Aalkjaer Christian , Nielsen Vibeke Secher , Matchkov Vladimir 
Published: June 2021

Two Ca2+‐activated Cl− currents (ICl(Ca)) are present in vascular smooth muscle (VSMC). One is cGMP dependent, the other is characterized as a classical ICl(Ca). Here we downregulate bestrophin‐3 (best3) and TMEM16A, to assess their importance for the two ICl(Ca) and for the role of ICl(Ca) in vascular function.Best3 and TMEM16A were downregulated in rat small mesenteric arteries using siRNA. Knockdown was confirmed at mRNA and protein levels 3 days after transfection.Best3 downregulation suppressed the cGMP‐dependent ICl(Ca) while TMEM16A downregulation suppresed both ICl(Ca)s. Both best3 and TMEM16A downregulation suppressed oscillations in vascular tone i.e. vasomotion. Best3 downregulation was without effect on sensitivity and maximal force production to norepinephrine while TMEM16A downregulation significantly reduced both. Also the force production to 125 mM KCl was reduced by TMEM16A downregulation.We conclude that TMEM16A is essential for both ICl(Ca)s while best3 may be modifying the TMEM16A current characteristics in a subset of channels. The cGMP‐dependent ICl(Ca) is critical for vasomotion and normal expression of TMEM16 is essential for VSMC conctractility.
Interaction between eNOS translocation and phosphorylation in flow –induced NO production
Authors: Boric Mauricio P , Figueroa Xavier F , González Daniel R , Durán Walter N 
Published: June 2021

Flow‐induced eNOS activation may involve the interaction of several signaling processes, such as eNOS phosphorylation, binding to Ca2+‐calmodulin, dissociation from caveolin (cav‐1) and/or translocation from membrane. We studied NO production (chemiluminescence), eNOS subcellular distribution and phosphorylation in intact resistance vessels of the isolated rat mesenteric bed submitted to step changes of flow rate. Flow increase (2 to 10 mL/min) induced a biphasic rise in NO production: a transient phase that peaked at 15‐sec and lasted 3–5‐ min, followed by a sustained phase, which lasted until the end of stimulation. Concomitantly, flow caused a rapid translocation of eNOS from the microsomal compartment to the cytosol and Golgi, which was paralleled by a 50% reduction in the eNOS‐cav‐1 association. In addition, the transient NO production, eNOS translocation, and eNOS dissociation from cav‐1 depended on extracellular Ca2+. In control or Ca2+‐free conditions, flow rise increased eNOS phosphorylation at ser‐1177 in an Akt‐dependent manner. Blockade of the PI3K‐Akt pathway abolished the sustained, but not the transient phase, of flow‐induced NO release. We conclude that flow‐induced NO production involves rapid Ca2+‐dependent eNOS translocation from membrane, while PI3K‐Akt‐ dependent phosphorylation accounts for the sustained eNOS activation by prevailing flow.Fondecyt 1090757 & Anillos‐Act71
Pericytes Contribute to Exercise‐Induced Skeletal Muscle Hypertrophy
Authors: Zou Kai , Huntsman Heather D. , Valero Carmen , Skelton John T. , Adams Joseph T. , Mahmassani Ziad , Boppart Marni D. 
Published: June 2021

Pericytes are perivascular cells with stem cell potential found in a variety of tissues. We have demonstrated that pericytes accumulate in skeletal muscle overexpressing the α7 integrin (α7Tg) and α7Tg mice exhibit increased muscle growth following exercise.PURPOSEThe purpose of this study was to determine whether pericytes contribute to muscle growth and whether this effect is enhanced by exercise.METHODSca‐1+CD45− cells were isolated from α7Tg gastrocnemius (GAS), and labeled with DiI. Recipient C57BL6 mice were exposed to 30 min downhill running 1 hour before cell injection (4 × 104) into GAS. The contralateral leg was injected with saline. Animals were then assigned to either sedentary (SED) or exercise trained (EX) group. EX mice were exposed to downhill running 3 times/wk for 2 wks.RESULTSSca‐1+CD45− cells expressed pericyte markers (CD90, CD140b, NG2, and CD146). DiI‐labeled pericytes did not directly form new fibers and did not fuse with existing fibers. However, Pax7+ satellite cells, mean fiber cross sectional area, percentage of larger caliber fibers (2000 to 3000 μm2) and number of nuclei per fiber were significantly increased in Cell/EX compared to Saline/EX (P<0.05).CONCLUSIONSThis study demonstrates that exercise enhances the ability for pericytes to indirectly increase muscle growth and may provide the mechanistic basis for exercise‐induced hypertrophy.
GATA‐4 Gene Transfer Increases Mesenchymal Stem Cell Mediated Myocardial Salvage through miRNA Regulation and Bioactive Molecules Migration between Cells
Authors: Xu Meifeng , Yu Bin , Pasha Zeeshan , Wang Yigang 
Published: June 2021

We hypothesized that GATA‐4 enhanced mesenchymal stem cell (MSC) mediated ischemic heart repair via regulating miRNA (miR).Methods and ResultsGATA‐4 was transduced into MSC (MSCGATA‐4) using the murine stem cell virus retroviral expression system. Overexpression of GATA‐4 downregulated miR‐15 family (miR‐15b, miR‐16, and miR‐195) and upregulating miR‐221/222 in MSC assayed using miR microarray and quantitative RT‐PCR. GATA‐4 significantly increased MSC survival evaluated by counting Annexin‐V+ cell and by MTT intake. MSCGATA‐4 markedly protected myocytes (CM) against ischemic injury examined through measurements of LDH release, MTT intake, and Annexin‐V staining. Fluorescence in situ hybridization and immunostaining results showed that miR‐221 as well as Bcl‐w and VEGF, two proteins of target genes of miR‐15 family, were transferred from MSC to CM. Gap junctions were observed between CM and MSC in a co‐culture system. The rats transplanted MSCGATA‐4 following left anterior descending coronary artery ligation showed a significantly improved cardiac function by echocardiography. Furthermore, histological studies revealed reduced infarction size and increased angiogenesis.ConclusionsOverexpression of GATA‐4 regulates miR expression in MSC, which plays an important role in MSCGATA‐4 mediated salutary effects on improving cardiac function and cardioprotection.
Hypothermia Protects Against Myocardial Microvascular Damage (No‐Reflow) Even When Initiated After Coronary Artery Reperfusion
Authors: Hale Sharon Lee , Kloner Robert A 
Published: June 2021

We tested the effects of hypothermia (H) on no‐reflow when H is initiated only at reperfusion; a time point that many studies have shown is too late to reduce myocardial infarct size (IS).MethodsRabbits received 30 m coronary artery occlusion and 3 h reperfusion. Hearts were treated with topical H (~32ºC) at 5 m before (HI, n = 14) or 5 m after (HR, n = 12) reperfusion. Controls remained normothermic (N, ~38ºC, n=14). Ischemic risk zone, no‐reflow zone, and necrosis were measured.ResultsThe ischemic insult was comparable in all groups (26–30% of left ventricle, p = ns). As we and others have observed, H started at this time failed to significantly reduce IS compared with N hearts (27 ± 3% of risk zone, HI; 42± 4%, HR and 34 ± 5%,N p =NS, ANOVA). However, the extent of the no‐reflow defect was significantly reduced in hearts treated with H, even when started after reperfusion (46±9% of the necrotic area, HI; 50±5%, HR; versus 80±8%, N; p <0.05 HI and HR vs. N). There was a significant treatment effect of H on the regression between the extent of the no‐reflow zone and that of the necrotic zone (ANCOVA, p = 0.003).ConclusionsThis study shows that myocardial temperature reduction dramatically reduces no‐reflow injury even when H is initiated too late to reduce overall IS. These data suggest that the microvasculature is especially receptive to the salvaging properties of hypothermia.
Early MRI findings of targeting the NG2 proteoglycan in GBM
Authors: Rygh Cecilie Brekke , Thuen Marte , Poli Aurélie , Wang Jian , Løkka Guro , Huuse Else Marie , Thorsen Frits , Enger Per Øyvind , Chekenya Martha 
Published: June 2021

Glioblastoma multiforme (GBM) is an aggressive brain tumor where patients have median survival of only 14.6 months. High NG2 expression in GBMs correlates with increased angiogenesis, drug resistance and shorter overall survival. We aimed to target NG2 with monoclonal antibodies (mAb) combined with natural killer (NK) cells in an adoptive immunotherapy approach in athymic rats bearing human GBM. The treatment response was monitored longitudinally using multiparametric MRI including morphological, dynamic contrast enhanced (DCE) and diffusion weighted imaging. The animals were divided into no treatment (n=8), mAb (n=9), NK cells (n=12) and mAb+NK cells (n=8). The overall survival, histological analyses and DCE‐MRI showed that the combined mAb+NK had therapeutic efficacy, where the leakage space (ve) was significantly increased indicating increased cell death. Changes in the microvascular parameters transfer constant (Ktrans) and area under the curve (AUC) were transiently detected in the mAb and NK cell groups. Diffusion values showed no significant change over time. Multiparametric MRI may facilitate individualized therapy by early detection of treatment responses.Support: The Norwegian Cancer Society, Western Norway Regional Health Authority and National Functional Genomics Programme (FUGE) of the Research Council of Norway
The influence of phytomedicine on metabolic processes of white rats undergone to ionized radiation
Authors: Ilderbayev Oralbek , Dalenov Erbolat 
Published: June 2021

The purpose of this experimental research is to study the influence of gamma‐radiation on metabolic processes of white rats undergone to ionizing radiation. The is a conclusion of the ethical committee (protocol N5, 2010, State medical university, Semey). Animal experiments were carried out in accordance with the order of the Helsinki Declaration on the humane treatment of animals. The levels of LPO, diene conjugates (DC) and MDA in thymus, spleen and lymph nodes of small intestine were tested.In the II series of experiment 30 days after irradiation by common gamma‐rays in the dose equal to 6 Gray, the reliable increase of DC contents was observed, that was 2.75 times higher in liver, 1.37 times higher in lymph nodes of small intestine, 2.5 times higher in thymus and 2.38 times higher in spleen as compared to control animals. The MDA amounts significantly increased in thymus (in 1.68 times) and in spleen (in 1.7 times, ð<0.05). The increase of MDA concentration in liver was equal to 1.63 times (ð<0.05). No changes were observed in lymph nodes of small intestine. Finally, obtained research results show that in case of exposure to common gamma‐rays in a dose of 6 Gray, the concentrations of DC and MDA increase in liver, thymus and spleen.
Inter‐individual differences in rapid vasodilation in older males with and without type 2 diabetes
Authors: Kellawan J. Mikhail , Bravo Michael F. , Moynes Jackie S. , Walsh Jeremy J. , Bentley Robert F. , Tschakovsky Michael E. 
Published: June 2021

PURPOSETo identify if rapid vasodilatory responses differ between individuals with or without type 2 diabetes.METHODS13 males (7 type II diabetics (T2D), 6 healthy controls (CON)) lay supine with the arm at heart level and completed 6 trials of single handgripping contractions (3 trials/day/contraction intensity, on 2 separate days, 1 s contraction duration) at 10, 20, and 40 % of their maximal voluntary contraction (randomly ordered). Forearm brachial artery blood flow (FBF, echo and Doppler ultrasound), mean arterial pressure (MAP, finger photoplethysmography) were measured continuously.RESULTStension‐time integral of single contraction force production (kg·s) vs. FBF relationships were constructed for each individual. There was no difference in the slope (4.7 ± 2.9 vs. 4.8 ± 2.5) or y‐intercept (y‐int) (35.2 ± 32.5 vs. 23.3 ± 15.2) between T2D and CON. However, there was considerable variation in both the slope and y‐int between subjects in each group. T2D coefficient of variation (COV) of slope was 64% and y‐int was 93%. COV for the slope in CON was 52% and y‐int 65%. Despite the variation, the r2 value for each individual was strong, ranging from 0.34–0.7 (σ = 0.51 ± 0.14) in T2D and 0.44–0.97 (σ = 0.76 ± 0.22) in CON.CONCLUSIONOlder males exhibit substantial inter‐individual rapid vasodilatory responses to muscle contraction. These individual differences do not appear to be influenced by type 2 diabetes.
Oxygen dependence of respiratory rate (VO2) in rat spinotrapezius muscle in situ measured with phosphorescence quenching microscopy (PQM)
Authors: Golub Aleksander S , Pittman Roland N 
Published: June 2021

ObjectiveThe sensitivity of isolated cells to PO2 is described by Hill's equation with a low Km (< 5 torr). Cells in intact tissues are more sensitive to O2 deficiency. To study the oxygen dependence of VO2 in muscle fibers we developed a method to register and interpret O2 disappearance curves (ODC).MethodWe employed PQM using a probe distributed in the interstitium. Rapid pressure onset to the tissue extruded most of the RBCs from the muscle vessels making the ODC independent of hemoglobin. The contribution to the O2 consumption by PQM was evaluated and accounted for. The corrected ODC was converted into the PO2 dependence of VO2. Fitting equations obtained from a model of heterogeneous PO2 distribution was applied to recover the parameters of respiration in muscle fibers.ResultsIn 6 muscles the rate of O2 consumption at rest was Vmax = 139 ± 6 nl O2/cm3•s, Km = 12 ± 2 torr and the correlation between them was 0.94. The PO2 drop across a fiber was Ä = 4.1 to 4.9 torr. Critical PO2 was estimated as 22 torr at VO2 = 90 nl O2/cm3•s.ConclusionThe oxygen dependence of respiration can be measured in thin muscles under different experimental conditions. In resting muscle Km and critical PO2 are substantially lower than interstitial PO2 = 51 ± 3 torr, a result discordant with the hypothesis of metabolic regulation of oxygen supply to tissue. The PO2 gradient across a muscle fiber was found to be small.Support: NIH grant R01HL18292
Effects of wall shear stress on NO simulation in arterioles
Authors: Kim Sangho , Cho Seungkwan , Namgung Bumseok 
Published: June 2021

The shear stress acting on the endothelium is a dominant mechanical stimulus that modulates the production rate of NO in the endothelial cells. Thus, determination of the wall shear stress (WSS) is important in studying the flow‐induced vasodilation. Recently, we have reported a way to estimate WSS in small arterioles by measuring the cell‐free layer width and edge velocity of red cell core, and used the method in NO simulation studies. In using that method, we assume that the flow within the cell‐free layer is steady. However, it has been known that variations in flow velocity due to the arterial pulse would exist in arterioles. Thus, in this study, we have considered temporal changes of the edge velocity of red blood cell core resulting from the temporal cell‐free layer width variations in estimating the WSS in the vessels. Linear and non‐linear velocity profiles within the layer were used to estimate the WSS. The temporal variation results of the WSS were utilized to predict NO bioavailability in the arterioles. We found a slight but significant difference in estimated WSS by using different velocity profiles in the cell‐free layer. However, NO simulation showed that this slight difference of WSS did not lead to a significant change in NO bioavailability.This work was supported by NUS URC Grant R‐397‐000‐091‐112.
Sub‐contractile sphingosylphosphorylcholine enhances vasoreactivity via reactive oxygen species
Authors: Ward Jeremy PT , Aaronson Philip I , Snetkov Vladimir A 
Published: June 2021

Sphingosylphosphorylcholine (SPC), at concentrations that do not cause contraction (<1uM), causes potentiation of vasoconstriction to other agonists or depolarisation (Snetkov et al, Hypertension 2008;51:239–245). Our objective was to determine whether this was related to activation of NADPH oxidase and production of reactive oxygen species (ROS).METHODSSmall pulmonary or mesenteric arteries were mounted on a myograph, challenged with depolarising solutions containing ~23 mM KCl to elicit a small contraction, and incubated with SPC (1uM) before being re‐challenged.RESULTS0.2 to 1uM SPC caused substantial potentiation of depolarisation‐induced force to between 400 and 800% of control in both rat and mouse arteries. Tempol (3mM) suppressed potentiation (e.g. PA: 526 +/− 220%; +tempol: 200+/−60%, n=5). SPC enhanced ROS production estimated by lucigenin and DCF. Potentiation was abolished in p47phox −/− mice (n=6). 0.2 uM SPC enhanced voltage activated calcium current in whole cell patch by ~30% (p<0.01), and this was mimicked by exogenous ROS. We conclude that low concentrations of SPC may cause hyperreactivity via NADPH oxidase and elevation of ROS, which enhances calcium entry via L‐type channels. Funded by the Wellcome Trust
Restoration of serum euthyroidism is inadequate to reverse cardiac dysfunction in experimental hypothyroidism
Authors: Weltman Nathan Y , Savinova Olga V , Chen Yuefeng , Schlenker Evelyn H , Youmans Steven , Gerdes A. Martin 
Published: June 2021

Clinical observations suggest a strong link between hypothyroidism (H) and poor outcomes in heart disease. We evaluated the efficacy of 2 weeks of Triiodothyronine (T3) in drinking water administered to hypothyroid rats with cardiac dysfunction to characterize the dosage of T3 that restores serum TH levels and cardiac function in propylthiouracil (PTU) induced H. PTU treatment reduced serum THs, small resistance vessels, and caused cardiac atrophy and LV dysfunction. PTU led to increased wall stress, primarily owing to a relative decrease in LV posterior wall thickness. Treatment with 3μg/kg/day restored serum TH levels while 5μg/kg/day reversed cardiac atrophy and wall thinning. A significant elevation in serum THs was necessary for complete LV functional restoration.

LV Function

HR
LV ESP
dP/dT
−dP/dT
LV FS

Control
366 (48)
142 (14)
10790 (2499)
−11910 (2299)
41 (5)

PTU
229 (38) *
105 (12) *
4209 (626) *
−4266 (891) *
35 (3) *

PTU + 3 T3
270 (27) * †
107 (13) *
5366 (718) *
−5623 (1120) *
36 (6)

PTU + 5 T3
313 (27) * †
113 (10) *
6223 (845) *
−6399 (999) *
38 (4)

PTU + 10 T3
363 (47) †
139 (21) †
9380 (1890) †
−11097 (3075) †
42 (4) †

p<.05 vs Control;
p<.05 vs PTU

In PTU induced H, restoration of serum THs was not associated with restoration of cardiac function suggesting that serum TH levels might not accurately reflect cardiac TH status. Short term T3 dosing to restore serum THs is inadequate to fully reverse cardiac dysfunction in PTU induced H.