bluuebunny/crossref_metadata_2025_split huggingface dataset:
INHIBITION OF FERROPTOSIS BY LIPROXSTATIN‐1 COMPOUND PROTECTS THE MYOCARDIUM AGAINST ISCHEMIA/REPERFUSION INJURY BY DECREASING VDAC1 LEVELS AND INCREASING IN GPX4 ACTIVITY
Authors: Feng Yansheng C. , Imam Aliagan Abdulhafiz C. , Tombo Nathalie C. , Bopassa Jean C. 
Published: April 2020

Ferroptosis is a non‐apoptotic form of cell death characterized by iron‐dependent accumulation of lethal lipid reactive oxygen species (ROS) and liproxstatin‐1 is a potent inhibitor of ferroptosis. We investigated whether Liproxstatin‐1 can protect heart against ischemia/reperfusion (I/R) injury and determine the mechanism underlying cardioprotection. Isolated C57BL/6J mice hearts were subjected to 35 min ischemia followed 120 min reperfusion and treated with Liproxstatin‐1 (200nM). Myocardial infarct size was assessed at the end of the reperfusion, mitochondrial integrity was measured by analyzing cristae morphology and ROS production was assessed using amplex red method. The calcium retention capacity (CRC) required to induce mitochondrial permeability transition pore (mPTP) opening was measured using calcium green dye. The levels of mitochondrial proteins cyclophilin D (CypD), Glutathione peroxidase 4 (GPX4), VDAC1, 2 and 3 were assessed by Western blot; and GPX4 activity was measured using a kit. We found that
liproxstatin‐1 treatment decreased myocardial infarction size, ROS production, and VDAC1 expression as well as preserved mitochondrial structural integrity by protecting cristae from damage. These mitochondrial effects of
liproxstatin‐1 were associated with the increase in the GPX4 levels and activity. But,
liproxstatin‐1 did not affect the CypD, VDAC2, and VDAC3 expression as well as mitochondrial CRC. Together, these result indicate that
liproxstatin‐1 treatment protects myocardium against I/R injury by increasing GPX4 activity resulting in the decrease in mitochondrial ROS production; preserving mitochondrial structure as well as decrease in VDAC1 (but not VDAC 2 and 3) expression. Liproxstain‐1 cardioprotective action does not involve the regulation of the mPTP opening. These results point to the cardioprotective role of anti‐ferroptosis compound after I/R.Support or Funding Information[NIH RO1 grant HL138093 (JCB)]
Functional Characterization of Position 271 in NTCP, a Predicted Rheostat Location
Authors: Ruggiero Melissa , Malhotra Shipra , Karanicolas John , Swint-Kruse Liskin , Hagenbuch Bruno 
Published: April 2020

BackgroundHuman Na+/taurocholate cotransporting polypeptide (NTCP) is a sodium dependent bile acid transporter expressed at the basolateral membrane of human hepatocytes. It is important for the enterohepatic circulation of bile acids, such as taurocholate (TCA), but it also transports other compounds including estrone‐3‐sulfate (E3S) and rosuvastatin. We previously identified a rheostat position at a naturally occurring polymorphism, S267F. That is, when other amino acids were substituted into this position, progressive changes in function were observed.AimThe purpose of the current study is to determine whether position N271, a predicted rheostat, is indeed another rheostat position in NTCP.MethodsThe crystal structures of two bacterial NTCP homologs were used to model the structure of human NTCP in the inward‐open and outward‐open conformations. Mutations were then introduced into the structural models and the energetic effect on protein stability was evaluated using the Rosetta software. Based on these calculations we predicted that N271 is a rheostat. Mutants for position N271 were generated using site‐directed mutagenesis and the resulting proteins were transiently expressed in HEK293 cells. The functions of the mutants were characterized by measuring uptake of radiolabeled model substrates: [3H]‐taurocholate, [3H]‐estrone‐3‐sulfate, and [3H]‐rosuvastatin. Plasma membrane expression levels were determined by surface biotinylation assays.ResultsInitial transport studies using nanomolar concentrations of TCA, E3S, and rosuvastatin indicated a variety of intermediate functional outcomes for the mutants. Furthermore, this alteration in function was substrate dependent, which is consistent with our findings for S267. Some mutants, such as N271A, transport substrates similar to wild‐type NTCP, while others, like N271K, show variation depending on the substrate. N271P consistently transports all substrates minimally. In addition, there is no correlation between the initial uptake results and the Rosetta energies.Summary and ConclusionsInitial transport studies demonstrate that position N271 is a rheostat position, as predicted by the alteration in Rosetta energy scores. However, there was no correlation between the calculated energy scores and the functional results. This suggests that functional outcomes of specific amino acid replacements at position N271 may arise from more complex conformational changes than were captured by the two modeled states. Additional experiments should help to determine to what extent the observed change in function is due to variations in the substrate affinity, the turnover number or the transport capacity of the mutants.Support or Funding InformationP30 GM118247, GM077336, and W. M. Keck Foundation
Sprouting Angiogenesis Contributes to Coronary Collateral Growth Induced by Repetitive Ischemia in Adult Mice
Authors: Jamaiyar Anurag , Juguilon Cody , Richardson Devan , Gadd James , Wang Tao , Enrick Molly , Goodner Rayana , Chilian William M. , Yin Liya 
Published: April 2020

In the United States, coronary heart diseases (CHD) are the leading cause of mortality and morbidity. A well‐developed coronary collateral circulation ameliorates the consequences of CHD, reducing the incidence of sudden death and infarct sizes following coronary occlusion. Stimulation of coronary collateral growth (CCG) is also an alternative therapeutic approach to patients with intractable angina pectoris. The importance of CCG is undisputable, but the process and mechanism underlying CCG is unclear. We developed a mouse model of CCG induced by repetitive ischemia (RI) and validated CCG by contrast echocardiography to measure the coronary blood flow in the normal zone (NZ) and the collateral dependent zone (CZ). We also used Micro‐CT scans to reconstruct the coronary vasculature in 3D and quantify CCG. In this study, we crossed ROSA mT/mG double fluorescent reporter mice with cell type‐specific cre mice to investigate the roles that different cell‐types play at various stages of CCG. Mice were subjected to the RI protocol and their cardiac function and coronary blood flow was measured by echocardiography. Following sacrifice, hearts were fixed for immunostaining or imaging under confocal and multiphoton microscopy. In ROSA mT/mG floxed, Apln cre mouse hearts, large vessels (diameter of 20–50 μm) expressing GFP were identified in the collateral dependent zone in the early stage of RI, indicating that they originated from sprouting endothelial cells. At the end of RI, a complete network of these vessels was observed anastomosing with existing vasculature from the NZ. Immunostaining revealed an outer layer of smooth muscle cells in these vessels, suggesting the arteriogenesis or arterialization. Interestingly, in ROSA mT/mG floxed, Lyz2 cre mouse hearts, GFP expressing myeloid cells were observed in high numbers around newly formed large vessels, suggesting that immune cell recruitment occurs in the early stages of CCG. Our preliminary data show that coronary collaterals form in response to RI, are of microvascular origin and are associated with early recruitment of immune cells to the CZ. Our further study will focus on the process of CCG in greater detail at the molecular and cellular level, potentially leading toward a therapeutic application of induced CCG in patients of ischemic heart diseases.Support or Funding InformationThe research is funded by National Institutes of Health grant 2R01HL103227‐05 (YZ, LY), 1R01HL135110‐01 (WMC, LY), 1R01 HL137008‐01A1 (LY) from American Heart Association (LY).
Correlation of Stroop Effect in Medical Students to Their Performance in Pharmacology National Board of Medical Examiners (NBME) Examination
Authors: Panta Raju , Paudel Keshab Raj , Toth Stephen , Olsen John 
Published: April 2020

ObjectiveThe Stroop test is used to assess selective attention in cognitive psychology. Interference between word meaning and ink color in Incongruent Stroop test prolongs reaction time, which involves the brain searching for some collection of the stored information for prompt use. This is called the Stroop effect. Previous studies have reported the strong correlations between the Stroop effect and academic performance. Therefore, we aimed to study the correlation of the Stroop effect in medical students to their performance in pharmacology NBME examination.MethodsFor this study, 40 medical students who completed their pharmacology NBME examination were selected. The Stroop, congruent and incongruent, tests were performed using the EncephalApp Stroop Test (Android/iOS). In Congruent test (Stroop Off), the subjects were asked to select ink color of the hashtag (#) symbols printed in different ink colors (red, blue, and green). In Incongruent test (Stroop On), the subjects were asked to select the ink color of the words RED, BLUE, and GREEN printed in different ink colors, e.g., the word “RED” printed in blue ink had to be selected as blue. Each subject practiced each test for two attempts and 5 attempts of each test were then recorded.The EncephalApp Stroop Test automatically recorded the results of the tests as duration in seconds, which include Congruent Stroop (OffTime duration), Incongruent Stroop (OnTime duration), OffTime plus OnTime duration, OnTime minus OffTime duration. The results of OnTime minus OffTime duration of the Stroop test and pharmacology NBME examination scores were tabulated in Microsoft Excel and descriptive analysis was done. The correlation of the “OnTime minus OffTime duration” to pharmacology NBME examination scores was determined by a Pearson correlation coefficient and regression analysis.ResultsThe correlation coefficient (adjusted r2) of our study was −0.0255 and significance F was 0.862. The “OnTime minus OffTime duration” in medical students was not correlated with the pharmacology NBME examination score (r (38) = 0.0283, p = 0.862). The regression model predicted only 0.08% (R2 = 0.0008) of the pharmacology NBME examination score of medical students.ConclusionThe Stroop effect in medical students is insignificantly correlated with their performance in pharmacology NBME examination. However, correlations of the Stroop effect in medical students with their performance in other subjects and examinations need to be assessed in further studies.Support or Funding InformationThe study was supported by the Trinity Medical Sciences University School of Medicine, St. Vincent and the Grenadines.
Regulation of Coronary Collateral Growth by MicroRNA‐21 in Metabolic Syndrome
Authors: Juguilon Cody , Richardson Devan , Gadd James , Enrick Molly , Jamaiyar Anurag , Xu Yanyong , Wang Zhiyuan , Wang Tao , Kolz Chris , Chilian William , Yin Liya 
Published: April 2020

Well‐developed coronary collaterals prove to be highly beneficial in salvaging ischemic myocardium, preserving cardiac function, and improving patient outcome post‐occlusion. However, this process of coronary collateral growth (CCG) is impaired in patients with metabolic syndrome. A complete understanding of the underlying mechanism, cell types, and genes contributing towards this impairment have yet to be elucidated. Therefore, uncovering more about the process may lead to potential therapeutics to induce CCG in metabolic syndrome. MicroRNA‐21 (miR‐21) is abundantly expressed in vascular and immune cells with numerous implications in cardiovascular disease including atherosclerosis, heart failure, and myocardial infarction. Furthermore, miR‐21 has been shown to regulate processes such as apoptosis, immune cell polarization, and endothelial progenitor proliferation. Additionally, miR‐21 dysregulation has been rooted in the diabetic population where lies a systemic inflammatory state. In this study, we investigated the role of miR‐21 in a mouse model of CCG.Our preliminary data suggested that down‐regulating miR‐21 rescues impaired CCG in a diet‐induced model of metabolic syndrome. Thus, we investigated the underlying mechanism and focused on the roles of miR‐21 in the maintenance of vascular homeostasis, function and inflammatory responses in metabolic syndrome. First, we studied whether miR‐21 regulates endothelial homeostasis by modulating the function and homing of bone marrow stem cells in metabolic syndrome. We analyzed endothelial progenitor cells (CD34+) in bone marrow and peripheral blood, along with endothelial proliferation in WT, miR‐21 knockout, and metabolic syndrome mice. Second, we studied whether miR‐21 regulates the inflammatory response in metabolic syndrome by characterizing bone marrow derived macrophages from WT and miR‐21 knockout animals along with mapping their influence on vascular cells. Third, we utilized a myeloid specific miR‐21 knockout to study its role during CCG in vivo. We found CCG to be blunted in these animals which suggests the importance of myeloid derived miR‐21 in healthy mice. Further studies will give us more insight on miR‐21 and its regulation of CCG in metabolic syndrome.Support or Funding InformationThe research is funded by National Institutes of Health grant 2R01HL103227‐05 (YZ, LY), 1R01HL135110‐01 (WMC, LY), 1R01 HL137008‐01A1 (LY)from American Heart Association (LY).
Young women are protected against leg endothelial dysfunction induced by adoption of a Westernized lifestyle
Authors: Smith James S. , Sales Allan K. , Walsh Lauren K. , Soares Rogerio Nogueira , Woodford Makenzie , Padilla Jaume , Manrique-Acevedo Camila 
Published: April 2020

BackgroundA Westernized lifestyle is characterized by sedentary behavior and consumption of diets high in refined sugars. This lifestyle is associated with weight gain, insulin resistance and the development of cardiovascular disease (CVD). Endothelial dysfunction is one of the key events in the pathogenesis of CVD. We have previously demonstrated that short‐term exposure to physical inactivity results in popliteal artery endothelial dysfunction evaluated by flow‐mediated dilation (FMD) in healthy men. However, it is unknown if transition to a Westernized lifestyle differentially impacts upper‐ and lower‐limb vascular health of healthy young women versus men.MethodsTwelve recreationally active women (aged 23±1 yrs; BMI 22.2±1.02 kg/m2) and 9 men (aged 27±2 years; BMI 24.73±1.27 kg/m2) were recruited from the community to undergo a 10‐day intervention period of sedentary behavior combined with consumption of six cans of high‐fructose carbonated soda per day. Ambulation, body composition, brachial (arm) and popliteal (leg) artery FMD and biochemical parameters were assessed at baseline and at the end of the intervention.ResultsAdoption of a sedentary behavior (reduction in ambulation from 12383±382 steps/day to 3992±151steps/day; p=0.0001) and high‐fructose consumption for 10 days did not result in significant changes in body weight or percent fat mass, but increased fasting triglycerides (basal: 63±7.26 vs. post: 79±9.23, p=0.04) and HOMA‐insulin resistance index (basal: 0.6±0.1 vs. post: 1.0±0.1, p=0.001), independent of sex. Notably, the Westernized lifestyle reduced popliteal artery FMD in men (basal: 5.7±1.0 vs. post: 3.1±0.8, p=0.04) but not in women (basal: 3.6±0.7 vs. post: 5.7±0.9, p=0.05). Brachial artery FMD remained unchanged following the intervention in both men and women.ConclusionsOur results indicate that physically active young females, but not males, are protected from leg endothelial dysfunction induced by short‐term exposure to a Westernized lifestyle.Support or Funding Informationnone
Ventromedial Hypothalamic Nucleus (VMN) Neuroestradiol: Sex Mono‐Versus Dimorphic Control of Glycogen Metabolism and Glucoregulatory Transmitter Signaling
Authors: Uddin Md. Main , Ibrahim Mostafa M.H. , Briski Karen P. 
Published: April 2020

The VMN functions within the neural glucostatic network. Estradiol exerts sex‐specific control of VMN nitric oxide (NO) and γ‐aminobutyric acid (GABA) transmission, which respectively stimulates or suppresses glucose counter‐regulatory hormone secretion. In the brain, the VMN is a principal site of neuroestradiol production by aromatase. This project utilized the aromatase inhibitor letrozole (LZ) alongside combinatory high‐resolution microdissection/Western blotting to address the premise that neuroestradiol governance of VMN metabolic sensory neuron protein marker [neuronal nitric oxide synthase (nNOS); glutamate decarboxylase65/67 (GAD)] expression is sex‐dimorphic. Glycogen metabolism impacts VMN nNOS and GAD profiles; here, LZ treatment effects on VMN glycogen synthase (GS) and phosphorylase brain‐ (GPBB; glucoprivic‐sensitive) and muscle (GPMM; norepinephrine‐sensitive) variant proteins were examined. VMN aromatase protein content was equivalent between the sexes; intracerebroventricular LZ infusion of testes‐intact male and ovariectomized, estradiol‐replaced female rats blocked insulin (INS)‐induced hypoglycemia up‐regulation of this profile. LZ elicited sex‐contingent changes in basal VMN nNOS and GAD expression, but blocked INS‐induced NO stimulation and GAD suppression in each sex. INS caused LZ‐reversible GPBB augmentation or suppression in male versus female, respectively. Male and female VMN GPMM content was correspondingly unchanged or decreased by INS; LZ reduced baseline GPMM expression in females only, but did not attenuate INS regulation in either sex. LZ correspondingly down‐ or up‐regulated baseline pyruvate recycling pathway marker protein expression in males (glutaminase) and females (malic enzyme‐1), and altered INS effects on the same proteins. Results show that neuroestradiol is required in each sex for optimal VMN metabolic transmitter signaling of hypoglycemia‐associated energy deficiency. Locally‐generated estradiol steroid involvement in sex‐specific hypoglycemic patterns of VMN glucoprivic‐sensitive GPBB expression may correlate with sex‐dimorphic glycogen mobilization during this metabolic stress. Neuroestradiol may also exert sex‐specific effects on glucogenic amino acid energy yield by actions on distinctive enzyme targets in each sex.Support or Funding InformationNational Institutes of Health DK‐109382
Souchinone Inhibits Mesangial Cell Fibrosis and Inflammatory Response Through TGF‐β1/Smad signaling and NLRP3 inflammasome pathway
Authors: Yoon Jung Joo , Han Byung Hyuk , Lee Hyeon Kyoung , Lee Yun Jung , Ahn You Mee , Kang Dae Gill , Lee Ho Sub 
Published: April 2020

Mesangial proliferative glomerulonephritis is characterized by an increased number of mesangial cells in the glomeruli in the kidneys and damage to the glomeruli by activation of some growth factors (e.g., angiotensin II) and deposition of extracellular matrix proteins. However, the effect of sauchinone on mesangial proliferative glomerulonephritis is still unclear. In the present study, we investigated the protective effect of sauchinone against angiotensin II (AngII)‐induced proliferation and fibrosis in human renal mesangial cells. Thus, this study was investigated the inhibitory effect of sauchinone (0.1–1 μM) on AngII‐stimulated mesangial cells proliferation and fibrosis. Sauchinone, one of the active lignan isolated from Saururus chinensis, was reported to possess broad bioactivities, such as anti‐inflammatory, anti‐oxidant, anti‐tumor, anti‐apoptosis and anti‐obesity effects.In this study, thymidine incorporation under AngII was significantly accelerated, which was inhibited by sauchinone in a dose dependent manner. In migration assays, a significant reduction in wound surface was observed in pretreatment of sauchinone. Sauchinone induced down‐regulation of cyclins/CDKs and up‐regulation of CDK inhibitor, p21waf1/cip1 and p27kip1 expression. In addition, AngII enhanced expression of fibrosis biomarkers such as collagen IV and CTGF, which was markedly attenuated by sauchinone. Sauchinone decreased TGF‐β1 and Smad‐2/Smad‐4 expression, whereas increased Smad‐7 expression under AngII. Furthermore, sauchinone inhibited AngII‐induced inflammatory factors level as well as NF‐κB p65 translocation and ROS production.These results suggested that sauchinone may alleviate mesangial proliferation and inflammation possibly involved in renal fibrotic process, further mesangial proliferative glomerulonephritis through disturbing TGF‐β1/Smad signaling and NLRP3 inflammasome pathway. Thus, sauchinone might prove to be effective in the treatment of renal dysfunction leading to mesangial proliferative glomerulonephritis.Support or Funding InformationThis work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIP) (2017R1A5A2015805)(2018R1D1A1B07050720).
SIRT4 Regulates Lysine Malonylation in Ovarian Granulosa Cells
Authors: Min Zheying , Xing Zeyu , Yu Yang 
Published: April 2020

SIRT4 belongs to the sirtuin family, which comprises NAD+ dependent lysine decaylases. SIRT4 has ADP‐ribosyltransferase, lipoamidase and decaylase activeties. In the study, we observed differential regulated lysine malonylationin ovarian granulosa cell lines (KGN) by the lable‐free quantitive technique. In SIRT4 depleted cells, there were a total of 65 malonylationsites from 56 proteins, including 39 up‐regulated malonylated proteins and 17 down‐regulated proteins. The differential regulated malonylation proteins were enriched in metabolic process and response to stimulus in GO biological process. We also detected the malonylation levels of PGK1 K131 and ENO1 K80 sites were decreased significantly in SIRT4 depleted cell lines, which were the same sites of PGK1 and ENO1 changed in PCOS primary ovarian granulosa cells (GCs). In addition, SIRT4 was decreased in PCOS GCs. In a conclusion, SIRT4 may regulate mitochondrial metabolic ability in PCOS GCs through modifying lysine malonylation of proteins in glycolysis pathway.Support or Funding InformationThis work was supported in part by the National Key R&D Program of China (2017YFC1001003, 2018YFC1003203), the National Natural Science Funds for general program (81571400, 81771580).