bluuebunny/crossref_metadata_2025_split huggingface dataset:
Decreased Expression of ETS‐2 in EPCs as an Early Marker of Cardiovascular Instability in CABG Patients, Beneficial Effects of Sitagliptin
Authors: Tejerina Teresa , Medina Úrsula , Carnero Manuel , Navarro‐Dorado Jorge , García‐Bouza Mónica , Reguillo Fernando 
Published: November 2023

AimIn patients with cardiovascular disease (CVD), the endothelial progenitor cells (EPCs) play a key role in endothelial repair processes. It has been hypothesized that Ets2 transcription factor could be involved in the instability of CVD/hyperlipidaemia. Recent studies have shown that the dipeptidyl peptidase‐4 (DPP‐4) is expressed on endothelial cells and appears to modulate their kinetics. Our main objective was to determine the degree of expression of transcription factor Ets2 and the endothelial repair factors Endoglin and CXCR4 in peripheral blood mononuclear cells from patients undergoing coronary artery‐bypass grafting (CABG), and to prove a possible beneficial effect of Sitagliptin.Methodsseventy patients undergoing CABG from the cardiac surgery service were selected for the study and categorized into five CVD stages. The Expression of Ets‐2, CXCR4, and Endoglin were measured by Western blot. Sitagliptin effect on EPCs and on the expression of different factors was studied by Western blot, ELISA and immunofluorescence. This study was conducted according to the World Medical Association Declaration of Helsinki and informed consent was obtained from all subjects before sampling.Resultsan increase in the expression of the transcription factor Ets‐2 in patients, without CV predictor risk factor associated with early stages of CV instability was observed (GI: 2.16 ± 1.4). Ets‐2 expression decreased in patients with longer evolution of CVD (GII: 1.16±0.8; GIII1.06±0.5; GIV: 0.91±0.3; GV: 0.56±0.3). A direct association of expression of Ets‐2 with age (p=0.04) and Endoglin expression (p=0.008), and indirectly with the evolution of CVD (p=0.008) and hyperlipidaemia (p=0.03) was found. A direct effect of Sitagliptin 1μM on the colony formation of EPCs at 6 and 12 hours (p=0.0077) and on expression of CXCR at 24 hours (p=0.0201) and SDF1 at 6 and 24 hours (p=0.0085) was observed.ConclusionsThe transcription factor Ets‐2 could be an early marker of cardiovascular instability associated with states of hyperlipidaemia. Our data suggest that a poor functionality of circulating EPCs could be associated with decreased expression of the transcription factor Ets‐2 in advanced stages of cardiovascular disease. Sitagliptin treatment of cultured EPCs, could help to revert EPCs deficient functionality. Therefore, the activatory response might depend on the SDF1‐CXCR4 axis.Support or Funding InformationFIS PI12/00590. Convocatoria CONACYT‐Gobierno del Estado de San Luis Potosí‐México 2012.
Amelioration of galactosamine‐induced acute hepatic injury by betaine in rats
Authors: Choi Yeo Jin , Na Jong Deok , Kim Young Chul 
Published: November 2023

Galactosamine (GalN) is a potent hepatotoxicant that inhibits RNA and protein synthesis via depletion of uridine nucleotide in the liver. Earlier studies suggested that some endogenous sulfur‐containing substances, particularly glutathione (GSH) and/or S‐adenosylmethionine (SAM), might antagonize the induction of liver injury by GalN. In this study, we determined the effect of betaine, a methyl donor used for remethylation of homocysteine to methionine, against GalN‐induced acute liver injury in association with alterations in the metabolomics of sulfur‐containing amino acids and related substances in the liver. Male Sprague‐Dawley rats were supplemented with betaine (1 % in drinking water) for 2 weeks prior to a GalN challenge (400 mg/kg, ip). Rats were sacrificed 24 h later for the assay. GalN treatment elevated serum alanine transaminase (ALT), aspartate transaminase (AST), and sorbitol dehydrogenase (SDH) activities significantly, and these changes were prevented by betaine supplementation. Histopathological examination revealed 30 % of multifocal necrosis with macrophage infiltration throughout the liver of GalN‐treated rats, which was also inhibited by betaine supplementation. GalN treatment increased methionine, but not SAM levels in the liver. Betaine supplementation further increased the hepatic levels of methionine, SAM, and the activity of methionine adenosyltransferase (MAT), an enzyme mediating the biosynthesis of SAM from methionine. However, hepatic GSH contents were not affected by betaine or GalN. GalN treatment elevated ornithine and spermidine levels significantly, but decreased putrescine levels in the liver, suggesting that the metabolic conversion of putrescine from ornithine was impaired. Betaine supplementation increased hepatic putrescine and spermidine levels significantly, but ornithine levels were unaltered. It is suggested that the hepatoprotective effect of betaine against GalN‐induced liver injury may be associated with an enhancement of polyamine biosynthesis via induction of MAT activity and SAM availability in the liver.Support or Funding InformationSupported by National Research Foundation (NRF) grants (No. 2014‐R1A2A1A11052967 and No. 2009‐0083533) funded by the Ministry of Education, Science and Technology (MEST), Korea.
Angiotensin‐(1–7) Prevents cardiovascular changes induced by hyperthyroidism
Authors: Senger Nathalia , Melo Marcos Barrouin , Santos Maria José Campagnole , Santos Robson Augusto , Barreto‐Chaves Maria Luiza Morais 
Published: November 2023

High levels of thyroid hormone (TH) are commonly associated with cardiac hypertrophy and with a hyperdynamic heart condition. We previously demonstrated that cardiac hypertrophy induced by TH is mediated by Renin‐Angiotensin System (RAS) activation. In present study we tested the hypothesis that elevated circulating Angiotensin‐(1–7) levels attenuate the cardiovascular changes induced by TH. Wild Sprague‐Dawley (SD) or transgenic rats (TG) that constitutively overexpress an Angiotensin‐(1–7)‐producing fusion protein (TGR‐L3292) received daily injections (i.p.) of triiodothyronine (T3) (7μg/100g of body weight/day) for 14 days in order to develop hyperthyroidism. Cardiac hypertrophy was characterized and echocardiography experiments were performed to evaluate cardiac function parameters. The animals were handled according to National Institute of Health guidelines (NIH) – guide for the care and use of laboratory animals. Hyperthyroid wild‐type rats (SD‐T3) presented a significant increase in the cardiac mass, which was undetectable in the transgenic rats treated with T3 (TG‐T3). The administration of A779 (5μg/Kg/h), an antagonist of Angiotensin‐(1–7) receptor (Mas receptor), prevented the anti‐hypertrophic effect of Angiotensin‐(1–7) observed in TG‐T3. Echocardiography parameters showed that TG‐T3 rats exhibited a mitigation of the cardiac hyperdynamic condition observed in SD‐T3 rats, improving the following parameters: ejection fraction (EF%), fractional shortening (FS%), E/A ratio and heart rate. On the other hand, the treatment with A779 inhibited or attenuated the cardioprotective actions of Angiotensin‐(1–7) observed in TG‐T3. Collectively, these findings improve understanding of the cardiac hypertrophy observed in hyperthyroidism and may provide groundwork for the development of a new pharmacological strategy to the cardiac hyperdynamic condition observed in this disease.Support or Funding InformationFoundation for the Support of Research in the State of São Paulo; [FAPESP #2013/16348‐6] and CNPq [National Council of Technological and Scientific Development].
Mitronic tsmiR miR6855 biosynthesis regulation by oxidative stress in the basal‐like breast cancer cells
Authors: Ellison Marshall , Misra Smita , Chaudhuri Gautam 
Published: November 2023

Radiation and chemotherapeutic agents eradicate tumors by inducing irreparable DNA damage. However, cancer cells often develop resistance to therapy by manipulating the DNA repair machinery. Conversely, a dividing cell constantly exposed to environmental and endogenous DNA damaging agents can transform into a tumor due to incorrect repair. Therefore the expression level of DNA repair proteins is critical both for cancer therapy and tumorigenesis. Our preliminary studies implied a unique mechanism involving an miRNA miR‐6855‐3p that promotes the biosynthesis of the transcriptional regulator protein SPRDX5 which enhances the expression of the tumor suppressor protein BRCA2 leading to the genotoxin and radiation‐resistance of aggressive SLUG‐high basal‐like breast cancer (BLBC) cells. The miRNA miR‐6855‐3p thus acts as a tumor suppressor miRNA (tsmiR). Interestingly, the gene for the miRNA miR‐6855‐3p is mitronic and is nested within the intron#13 of the USP20 gene which is a deubiquitinase. Thus, the transcription of miR‐6855‐3p gene is regulated through the USP20 gene promoter. We present evidence here that USP20 and miR‐6855 gene transcriptions are up regulated by oxidative stress. Tert‐butylhydroperoxide was used for oxidative stress. Under the oxidative stress conditions tested, NRF2 level and the levels of several NRF2‐regulated proteins are increased, indicating activation of NRF2 in the stressed BLBC cells. Under the stress conditions the levels of USP20 and miR‐6855‐3p are increased significantly. Knockdown of NRF2 prevented stress‐induced elevation of USP20 and miR‐6855‐3p RNA level in the BLBC cells indicating the involvement of NRF2 in this process. The binding of NRF2 to the USP20 gene promoter and its function were characterized by ChIP analysis, site‐directed mutagenesis and using the promoter‐luciferase reporter constructs. We conclude that the biosynthesis of the tsmiR miR‐6855‐3p in the BLBC cells is regulated by oxidative stress and involves NRF2. Since oxidative stress is a hallmark in the etiology and progression of metastatic breast cancer, understanding the redox regulation of a tsmiR that positively influences BRCA2 gene expression in the BLBC cells could be clinically significant.Support or Funding InformationSupported in part by DOD‐CDMRP IDEA Expansion Grant# BC103645 and NIH/NCI grant 1R21CA181920‐01 to GC and 1U54RR026140 to SM.
Mechanical Stretch on Endothelial Cells Promotes Monocyte Differentiation into Immunogenic Dendritic Cells
Authors: Loperena Roxana , Gomez Jose A , Engel Noah , Harrison David G 
Published: November 2023

Hypertension is a leading cause of mortality in Western society, attributed in part to the oxidative injury and inflammation. We have shown that dendritic cells (DCs) from hypertensive mice accumulate isolevuglandins (IsoLGs) that adduct to proteins and promote T cell activation. In hypertension, the endothelium is activated to produce reactive oxygen species and to express adhesion molecules and chemokines that attract inflammatory cells. Human monocytes that traverse the endothelium differentiate into monocyte‐derived DCs upon exposure to pro‐inflammatory state. We hypothesized that human endothelial cells exposed to mechanical stretch will promote conversion of human monocytes into activated DCs. We co‐cultured human aortic endothelial cells (HAECs) with monocytes from normotensive human donors and exposed the HAEC monolayer to either normal cyclical stretch (5%) or hypertensive cyclical stretch (10%) using the Flexcell® Tension System for 48 hours. We found that co‐culture of monocytes with HAECs exposed to 10% mechanical stretch have a marked increase in pro‐inflammatory cytokines such as IL‐6, I‐23A and IL‐1β compared to 5% stretch. HAECs exposed to 10% stretch promoted monocytes in culture to differentiate into DCs, as evidenced by the surface expression of CD209, CD83 and the co‐stimulatory marker CD86. These monocytes also had an accumulation of IsoLG‐adducted proteins compared to controls (69.73 ± 5.802 vs 10.79 ± 1.854 respectively, p = 0.0001) as evidenced by intracellular staining and flow cytometry. In addition, these monocytes in culture with endothelial cells exposed to 10% stretch expressed the phosphorylated form of STAT3 (pSTAT3) and this was prevented when cell cultures were treated with STAT3 inhibitor, stattic. Monocytes co‐cultured with 10% stretched HAECs induced a 1,500‐fold increase in CD4+ T cell proliferation and a 1,300‐fold increase in CD8+ T cells proliferation as monitored by CFSE compared to 5% stretch controls. Conversely, monocytes‐HAEC cultures exposed to 10% stretch and treated with STAT3 inhibitor prevented both CD4+ and CD8+ T cell proliferation. Monocytes were plated inside a transwell dish that only allows the exchange of small molecules while the endothelial cells were stretched to either 5% or 10%. We found that monocytes expressed DC markers, pSTAT3, and accumulated IsoLG‐peptides without direct contact with endothelial cells exposed to hypertensive mechanical stretch. These data show that endothelial cells exposed to mechanical stretch cross‐talk with monocytes to promote differentiation into DCs that are immunogenic potentially via the STAT3 pathway and that this is not cell contact‐driven. These findings give insight into a new mechanism of lymphocyte activation in the vascular endothelium during hypertension.Support or Funding InformationRuth L. Kirschstein National Research Service Award (NRSA) Diversity F31HL132526
Acute Exercise Rescues Cortex BDNF Signaling In High Fat Fed Male Mice
Authors: Baranowski Bradley , Peppler Willem T , MacPherson Rebecca EK 
Published: November 2023

High fat diet induced obesity and insulin resistance have been directly implicated in the neuropathology of Alzheimer's disease. It is thought that high fat diets induce a reduction in neuronal plasticity through a reduction in the neurotrophin, brain‐derived neurotrophic factor (BDNF). Previous work has demonstrated that acute exercise can reverse high fat diet induced alterations in cortices from obese mice, however the underlying mechanisms remain unknown. The purpose of this study was to determine the effects of a single bout of exercise on BDNF content and signaling in the prefrontal cortex from obese insulin resistant mice. Male C57BL/6 mice were fed a low (LFD, 10% kcals from lard) or a high fat diet (HFD, 60% kcals from lard) for 7 weeks. The HFD increased body mass and glucose intolerance (p<0.05). HFD mice underwent an acute bout of exercise (treadmill running: 15m/min, 5% incline, 120min) followed by a recovery period of 2 hours, after which point the prefrontal cortex was collected. Prefrontal cortex from HFD mice demonstrated lower BDNF protein content and phosphorylation of the BDNF receptor (TrkB) and downstream effector cAMP response element‐binding protein (CREB), as well as PGC‐1alpha and ER‐alpha protein content (p<0.05). Two hours following the acute exercise bout there was no change in BDNF protein content or mRNA expression. Further, there was no effect of exercise on the gene expression of PGC‐1alpha or ER‐alpha. However, TrkB and CREB phosphorylation, as well as PGC‐1alpha and ER‐alpha protein content were recovered (p<0.05). Our findings demonstrate for the first time that an acute bout of exercise can increase BDNF signaling in the prefrontal cortex of obese male mice.Support or Funding InformationRebecca EK MacPherson was supported by an Alzheimer's Society post‐doctoral fellowship as well as a research grant from the Alzheimer Society Foundation of Brant, Haldimand Norfolk, Hamilton and Halton.
Quantification of Sulfide in the Human Cutaneous Microcirculation Bioassay: Methylene Blue Assay Versus an Amperometric Sensor
Authors: Shank Sean , Alexander Lacy , Castro Rita 
Published: November 2023

Impaired microvascular function, characterized by attenuated nitricoxide (NO)‐mediated endothelium‐dependent dilation, is one of the earliestmanifestations of cardiovascular disease, and occurs prior to dysfunction inconduit arteries and veins. In addition to NO, hydrogen sulfide (H2S)is an important signaling molecule involved in the regulation of vascular tone throughits direct effects on vascular endothelial and smooth muscle cells, andindirect effects by interacting with the NO‐synthase signaling pathway. Atphysiologic pH, H2S is easily lost by dissipation into theatmosphere, making it difficult to reliably quantify in biological samples. Thepurpose of this experiment was to compare methods for quantifying H2Sconcentration in our in vivo bioassayexamining H2S‐dependent mechanisms in the human cutaneousmicrovasculature. We compared a sulfide‐sensitive amperometric sensor to amethylene blue assay to measure sulfide concentration in dialysate obtained fromintradermal microdialysis probes. We hypothesized that the methylene blue assaywould be more accurate than the amperometric sensor in quantifying H2Sconcentration because the former uses zinc acetate, which traps the H2Sin solution, preventing dissipation to the atmosphere. To test this we perfusedtwo different concentrations of Na2S (20 and 60 mM), a H2Sdonor, through four intradermal microdialysis fibers placed into the ventralforearm. Dialysate from the probes was collected in either phosphate‐bufferedsaline or in zinc acetate (1%) solution for immediate H2Squantification. The ratio between the sulfide content pre‐to‐post dialysis was quantified in one set of samples using the amperometric probe and in a second set of samples by methylene blue assay. Using the methylene blue assay, the sulfide ratios were 0.94 ± 0.06 and 0.91 ± 0.18 for 20 and 60 mM Na2S, respectively. Using the amperometric sensor, the ratios were 0.69 ± 0.16 and 0.74 ± 0.14 for 20 and 60 mM Na2S, respectively. We concluded thatthe methylene blue assay is a more accurate method to quantify H2Sconcentration in dialysate from intradermal microdialysis fibers. Therefore, amethylene blue assay may be a better method to quantify H2S concentration in microdialysis dialysate samples.Support or Funding InformationNIH HL093238 (LMA)
INTERMITTENT SPONTANEOUS BREATHING PREVENTS MECHANICAL VENTILATION‐INDUCED DIAPHRAGM ATROPHY AND DYSFUNCTION
Authors: Ichinoseki‐Sekine Noriko , Yoshihara Toshinori , Tsuzuki Takamasa , Morton Aaron , Hinkley Matthew J , Powers Scott K , Naito Hisashi 
Published: November 2023

Mechanical ventilation (MV) is used to provide adequate pulmonary ventilation for patients in respiratory failure. Although MV is often a life‐saving intervention, prolonged MV results in the rapid development of diaphragm atrophy and contractile dysfunction (collectively known as ventilator‐induced diaphragm dysfunction (VIDD)). Importantly, VIDD contributes to difficulty in weaning patients from MV, which is in turn associated with increased mortality and morbidity. Therefore, developing a strategy to protect the diaphragm against VIDD is important. Although studies have investigated the impact of prolonged MV on VIDD, limited data exist regarding the impact of intermittent spontaneous breathing during MV on protection against VIDD. Therefore, we investigated the effects of intermittent spontaneous breathing on VIDD. Adult male Wistar rats (n = ~10/group) were randomly assigned to one of three groups: 1) anesthetized control (CON) with no MV; 2) controlled MV (CMV) for 12 hours; and 3) intermittent spontaneous breathing during MV (1‐min spontaneous breathing phase per hour (IMV). In the IMV group, voluntary diaphragm activation occurred 89.2 ± 6.8 times during each minute of spontaneous breathing. As expected, CMV resulted in significant diaphragm atrophy and contractile dysfunction (P < 0.05) along with activation of caspase‐3 and phosphorylation of signal transducer/transcriptional activator‐3 (STAT3) in the diaphragm. In contrast, intermittent breathing prevented MV‐induced activation of caspase‐3 and phosphorylation of STAT3. Importantly, animals in the IMV group were protected against VIDD. These findings reveal that as little as 1‐min/hour of spontaneous breathing during MV is protective against VIDD, in part, by prevention of MV‐induced activation of caspase‐3 and STAT3 in the diaphragm.Support or Funding InformationThis work was supported by JSPS KAKENHI Grant Number 26350820 and 15KK0131 and NIH R01, R01AR064189
A Possible Role of Skeletal Muscle‐Derived Adiponectin in the Regulation of Skeletal Muscle Mass
Authors: Goto Katsumasa , Ito Rika , Higa Masaki , Yokoyama Shingo , Sugiura Takao , Miyata Hirofumi , Ohira Yoshinobu , Yoshioka Toshitada 
Published: November 2023

Aging‐associated severe skeletal muscle atrophy, so‐called sarcopenia, is considered as a risk factor for falls in older adults. Recent cohort studies shows high circulating adiponectin levels predict decreased muscle strength among older adults. Adiponectin, one of adipokines, is exclusively synthesized in adipocytes, is secreted into circulation, binds to adiponectin receptors (AdRs), especially AdR1, and exhibits insulin‐sensitizing effects to stimulate the utilization of glucose and lipids in skeletal muscle cells. We hypothesize that high adiponectin levels may have atrophic effects on skeletal muscle cells. Therefore, this study investigated aging‐associated changes in adiponectin expression in skeletal muscle and effects of high adiponectin levels on myogenic differentiation. All procedures for animal experiments were carried out in accordance with the Guide for the Care and Use of Laboratory Animals as adopted and promulgated by the National Institutes of Health (Bethesda, MD, USA) and were approved by the Animal Use Committee of Toyohashi SOZO University. Aging‐associated up‐regulation of adiponectin in fast extensor digitorum longus muscle was observed. Agonist for AdRs, AdipoRon, suppressed myogenic differentiation of C2C12 cells in a dose‐dependent manner. Knockdown of AdR1 in C2C12 myoblasts induced by small interfering RNA (siRNA), partially depressed the AdipoRon‐induced suppression of C2C12 differentiation. Aging‐associated up‐regulation of adiponectin in skeletal muscle may induced muscle atrophy in especially fast skeletal muscle.Support or Funding InformationThis study was supported, in part, by Grants‐in‐Aid for challenging Exploratory Research (26560372), and Grants‐in‐Aid for Scientific Research (C, 26350818) from the Japan Society for the Promotion of Science, the Uehara Memorial Foundation, the Naito Foundation, Graduate School of Health Sciences, Toyohashi SOZO University, Descente Sports Foundation, and All Japan Coffee Association. No COI.