bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sphingomyelin‐Cholesterol Complexes In Plasma Membranes
Authors: Endapally Shreya , Frias Donna , Tomchick Diana , Radhakrishnan Arun 
Published: June 2021

Sphingomyelin(SM) and cholesterol are lipids that are critical for the function of animal cells. Interplay between these two lipids is important for maintaining integrity of the myelin sheath that encases axonal cells and for maintaining functionally distinct pools of cholesterol in the plasma membranes of fibroblast cells. The nature of the interaction between SM and cholesterol has been long debated, with proposals ranging from complexes of the two lipids to no specific interaction between these two lipids.Here, we have developed a sensor to examine the interaction between SM and cholesterol in animal cell membranes. Our sensor is derived from a fungal toxin, ostreolysin A (OlyA). We find that OlyA binds to membranes of CHO‐K1 hamster cells when they contain both SM and cholesterol, but not when levels of either lipid are diminished by treatment with sphingomyelinase (which degrades SM) or cyclodextrin (which depletes cholesterol). In model membranes, OlyA shows no binding to dioleoyl‐phosphatidylcholine – cholesterol membranes even when the cholesterol concentration exceeds 50 mole%. Also, OlyA shows no binding to SM‐containing membranes when epicholesterol (a diasteromer of cholesterol) is present at concentration exceeding 50 mole%. Using X‐ray crystallography, we studied the interaction of OlyA with SM and cholesterol at the atomic level. This structural analysis combined with detailed mutagenesis led us to a single point mutation in OlyA that abolishes its cholesterol specificity while retaining SM specificity. Comparing the X‐ray structures of these two versions of lipid‐bound OlyA combined with ligand docking simulations revealed two distinct binding modes of OlyA to SM. We propose that one of these SM conformations reflects a complex with cholesterol. Studies in live cells show that this pool of SM/cholesterol complexes in plasma membrane is maintained at a constant level across a large range of cholesterol concentrations.Support or Funding InformationThis work was supported by the Welch Foundation (I‐1793) and the American Heart Association (12SDG12040267)This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Minocycline Inhibits PDGF‐BB‐induced Human Aortic Smooth Muscle Cell Proliferation and Migration via Induction of RECK
Authors: Higashi Yusuke , Srinivas Mummidi , Sukhanov Sergiy , Yoshida Tadashi , Delafontaine Patrice , Chandrasekar Bysani 
Published: June 2021

Minocycline is an FDA‐approved tetracycline antibiotic that exerts anti‐inflammatory and anti‐apoptotic effects independent of its bactericidal activity. For example, it attenuates neointima formation after arterial injury and atherosclerotic plaque development in an animal model of diet‐induced atherosclerosis via inhibition of smooth muscle cell (SMC) proliferation and migration; however, the molecular mechanisms underlying this inhibition are not completely known. Here we investigated whether minocycline inhibits PDGF‐BB‐induced primary human aortic SMC (HASMC) proliferation and migration in vitro. Our results show that PDGF‐BB stimulates proliferation (~2.92‐fold, P<0.05) and migration (~1.8‐fold, P<0.05) of HASMC via a redox‐sensitive mechanism involving NOX2 (inhibited by gp91dstat) and NOX4 (inhibited by GKT137831). Reversion‐Inducing‐Cysteine‐Rich Protein with Kazal Motifs (RECK) is a cell surface expressed, membrane anchored matrix metalloproteinase inhibitor. For the first time, our results show that PDGF‐BB downregulates RECK expression in a time‐dependent manner (by ~80% at 6 h, n=3, P<0.01), but induces miR‐221 and miR‐222 expression (~1.8‐fold and ~2.23‐fold, respectively). The reporter assays revealed that both miRs bind the 3′UTR of RECK mRNA, inhibiting its expression by ~50% (P<0.01). Supporting these observations, transduction of miR‐221 or miR‐222 mimics suppress RECK expression, but their antagomirs reverse PDGF‐BB‐induced inhibition of HASMC proliferation and migration. Further investigations revealed that PDGF‐BB activates the redox‐sensitive nuclear transcription factors NF‐kB and AP‐1 in HASMC, and shRNA directed against the AP‐1 subunit c‐Jun and the p65 subunit of NF‐kB each inhibit PDGF‐BB‐induced miR‐221 or miR‐222 expression, suggesting that PDGF‐BB suppresses RECK expression in HASMC in part via AP‐1‐ and NF‐kB‐dependent miR‐221 and miR‐222 induction. Notably, minocycline increases RECK expression dose‐dependently within the therapeutic dose of 1–100 μM, and inhibits PDGF‐BB‐induced HASMC proliferation and migration. Intriguingly, silencing RECK reverses the inhibitory effects of minocycline on PDGF‐BB‐induced migration and proliferation. Together, these results demonstrate that PDGF‐BB downregulates RECK expression in HASMC via AP‐1‐ and NF‐kB‐dependent miR‐221 and miR‐222 induction, and minocycline reverses PDGF‐BB‐induced ROS generation, miR‐221 and miR‐222 induction, and RECK suppression. These findings suggest that the induction of RECK is one of the mechanisms by which minocycline exerts vasculoprotective effects.Support or Funding InformationNIH R01‐HL‐070241 (PD)VA Merit Award I01‐BX002255 (BC)This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Absence of Heme Oxygenase‐1 Accelerates Smooth Muscle Cell Gene Expressions during Embryoid Body Development from Mouse Embryonic Stem Cells
Authors: Jiang Wei‐Cheng , Lai Yan‐Liang , Lin Chen‐Yu , Yet Shaw‐Fang 
Published: June 2021

Heme oxygenase (HO)‐1 is well known as a stress response protein, playing an important role for protecting cells and tissues from injury with its antioxidative and anti‐inflammatory properties. Although it possess crucial cytoprotective ability against physiological stress, the functions of HO‐1 in embryonic stem cell (ESC) differentiation remain to be elucidated. In previous study, we indicated that in the absence of HO‐1, induced pluripotent stem (iPS) cells are more sensitive to oxidant stress‐induced cell death and more prone to lose pluripotent markers without LIF. To investigate the role of HO‐1 in ESC differentiation and to eliminate the controversy of potential gene defects in iPS cells, we attempted to set up mouse HO‐1 knockout ESC lines from HO‐1 knockout blastocysts. Under the 3‐dimensional embryoid body (EB) formation from wild type D3 and HO‐1 knockout ESCs, we showed that at an early time point after EB differentiation, a lack of HO‐1 led to enhanced ROS level, accompanied with upregulations of master mesodermal regulator brachyury and endodermal marker GATA6. Furthermore, critical smooth muscle cell (SMC) transcription factor serum response factor and its coactivator myocardin were increased. Moreover, HO‐1 deficiency augmented Smad2 expression in ESCs and EBs, indicating that Smad2 not only mediates mesendoderm differentiation of mouse ESCs but also SMC development. Taken together, absence of HO‐1 contributed to higher level of mesodermal and SMC regulators, leading to accelerated and enhanced SMC marker expressions. Our results demonstrated a previously indeterminate function of HO‐1 in regulating SMC gene expressions during ESC‐EB development. More significantly, this finding may provide a novel approach to enhance SMC differentiation from ESCs.Support or Funding InformationNational Health Research Institutes and Central Government S&T grant, Taiwan (106‐0324‐01‐10‐07), Ministry of Science and Technology of Taiwan (MOST 104‐2320‐B‐400‐006‐MY3 and MOST 106‐3114‐Y‐043‐021), and National Health Research Institutes of Taiwan (CS‐106‐PP‐05).This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
A pharmacological model of TRPA1‐mediated nociception in zebrafish larvae for therapeutic discovery
Authors: Ko Mee Jung , Ganzen Logan C. , Leung Yuk Fai , van Rijn Richard M. 
Published: June 2021

Nearly 50 million people in the United States currently suffer from chronic pain disorder (CPD). CPD accompanies unrelieved and persistent pain lasting longer than 3 months. For many patients, current medications inadequately treat their symptoms or come with significant adverse effects, suggesting the need to find novel treatments. One novel therapeutic target for CPD is a calcium channel called Transient Receptor Potential channel subfamily A1 (TRPA1). However, the lack of robust in vivo models to investigate TRPA1 has been perceived as a challenge to drug discovery. Zebrafish model has been utilized for discovering neuroactive compounds. Their increased locomotive/swimming behavior upon TRPA1 activation has been interpreted as a nociceptive‐like phenotype. To increase the robustness of this model, we employed a less volatile and less neurotoxic TRPA1 agonist. We validated TRPA1‐mediated responses by a selective TRPA1 antagonist. Here, we first characterized the basic pharmacology of mouse and zebrafish TRPA1 ligands in HEK293 cells transiently expressing TRPA1. We used FLIPR®‐based calcium assay to record calcium influx, which is a measure of TPPA1 function. Additionally, we measured swimming behavior of zebrafish larvae (5 days post‐fertilization) following TRPA1 activation using a ViewPoint Zebrabox. In our studies, treatment with 100 μM TRPA1 agonist (ASP7663) increased calcium influx in HEK293 cells and swimming behavior of zebrafish larvae. Pre‐incubation of TRPA1 antagonist (HC030031) ablated in vitro calcium influx in a dose‐dependent manner and TRPA1‐mediated locomotive behavior in zebrafish larvae. Our findings validate that the zebrafish larvae can act as an in vivo model to investigate TRPA1‐targeted drugs for CPD. The increased robustness of our model will allow for a successful target‐based drug screening.Support or Funding InformationThe current research has been funded by a Collaborative Research Award from the Purdue Institute of Integrative Neuroscience (PIIN).This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Cinnamic Acid Derivatives as Novel Antinociceptives for Acute Pain
Authors: Priebe Alaini , Hunke Megan , Hyde Olivia , Martinez Wuilian , Capellen Caleb , Sonawane Yogesh , Chandra Surabhi , Natarajan Amarnath , Pattabiraman Mahesh 
Published: June 2021

Search for alternate pain medications has gained more importance in the past few years due to nervous system related side‐effects with opioids, gastrointestinal dysfunction associated with non‐steroidal anti‐inflammatory drugs (NSAIDs), and cardiovascular anomalies with cyclo‐oxygenase‐2 inhibitors (COX‐2). Phytomedicine has been quite effective for treatment of pain, as these have been used for generations in regional communities, and tend to lack any major side‐effects. A dimer of cinnamic acid, Incarvillateine (INCA), derived from the Chinese herb Incarvillea sinensis, has its primary antinociceptive action through the adenosine receptor. Adenosine‐mediated analgesia has become an attractive target as it has the least side‐effects. We hypothesized that derivatives of cinnamic acid dimers, which structurally mimic INCA, show potent antinociceptive action, and their effect is mediated through adenosine receptor action. Compounds were synthesized using novel cavitand‐mediated photodimerization method, which utilizes a macromolecule (gamma‐cyclodextrin) to control the excited state reactivity of photoactive compounds to yield target tetra‐substituted cyclobutanes (dimers). The dimers generated so far show significant suppression of formalin‐induced acute pain in mice hind paw. Antinociceptive effect of ferulic acid dimer and 3‐methoxy cinnamic acid dimer was observed primarily in the inflammatory phase, and the dimer binds to the adenosine 3 receptors (as revealed by computer modeling). The pain suppressing response of these dimers was similar to that observed with indomethacin, an anti‐inflammatory drug. Even though morphine was more effective than the synthesized dimers in reducing neurogenic and inflammatory pain, there was no visible neurogenic side‐effects observed with administration of the dimers as commonly observed with morphine, which suggests a primary non‐opioid action. Our further characterization and selection of INCA analogs, with predominant adenosine receptor action, will help us to generate a new class of antinociceptives with precise chemical modifications using CMP methodology.Support or Funding InformationUNK Undergraduate Research Fellowship (AP, MH, WM, CC); Great Plains IDeA CTR Pilot Grant (MP, SC)This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Contribution of p62/SQSTM1 to PDGF‐BB‐induced myofibroblast‐like phenotypic transition in vascular smooth muscle cells lacking Smpd1 gene
Authors: Zhang Peng , Chen Jiajie , Guan Yinglu , Li Xiang , Li Pin‐Lan , Zhang Yang 
Published: June 2021

Accumulating evidence indicate a critical role of acid sphingomyelinase (gene symbol Smpd1), a lysosomal hydrolase metabolizes sphingomyelin into ceramide, in controlling autophagic flux and vascular smooth muscle cell (SMC) homeostasis in atherogenesis. However, it remains elusive whether or not acid sphingomyelinase and autophagy play a modulatory role in SMC transition towards myofibroblast phenotype and extracellular matrix remodeling. In primary cultured SMCs from mouse coronary arteries, we demonstrated that PDGF‐BB stimulation produced an augmented proliferation in Smpd1−/− SMCs compared to Smpd1+/+ SMCs. More interestingly, PDGF‐BB induced more pronounced upregulation of fibroblast specific protein (FSP‐1), deposition of collagen type I, and expression of TGFβ1 in SMCs when Smpd1 is deleted. The increases in fibroblast markers in Smpd1−/− SMCs by PDGF‐BB were also accompanied by markedly elevated inflammatory status as shown by increased release of inflammatory cytokines (IL6 and IL18), expression of ICAM‐1, and monocyte adhesion. These data suggest that PDGF‐BB promotes a phenotypic transition in SMCs toward a myofibroblast‐like phenotype in the absence of acid sphingomyelinase function. Mechanistically, PDGF‐BB induced an exacerbated accumulation of autophagy substrate p62 in Smpd1−/− SMCs compared to Smpd1+/+ SMCs. In addition to impaired autophagic flux, autophagosome formation in Smpd1−/− SMCs was also suppressed by PDGF‐BB due to prolonged activation of Akt‐mTOR signaling, which further contributes to exacerbated p62 accumulation. Lastly, Akt inhibition or p62 gene silencing attenuated PDGF‐BB‐induced phenotypic changes observed in Smpd1−/− SMCs. Together, our data demonstrate, for the time, a p62‐dependent myofibroblast‐like phenotypic transition in Smpd1−/− SMCs, which indicates that acid sphingomyelinase‐regulated autophagy signaling plays a crucial role in maintaining the arterial smooth muscle homeostasis.Support or Funding InformationNational Heart, Lung, and Blood Institute grants (HL122769, HL122937) and the Young Scientists Fund of National Nature Science Foundation of China (No. 81202095).This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Limonene‐induced Activation of A2A Adenosine Receptors Reduces Airway Inflammation and Reactivity in a Mouse Model of Asthma
Authors: Narke Deven , Siddiquee Armaan , Patel Mehaben , Kurade Mangesh , Mustafa S Jamal , Ledent Catherine , Ponnoth Dovenia S. 
Published: June 2021

Animal models of asthma have shown that limonene (terpene in citrus fruits) reduces inflammation and airway reactivity. However, the mechanism of these effects is unknown. We hypothesized that limonene activates A2A adenosine receptors (A2AAR) to produce its effects in asthma, after comparing Glide scores for limonene (−5.19) and A2AAR agonist CGS 21680 (−8.43). We investigated the effects of limonene on lung inflammation and airway responsiveness to methacholine (MCh) as well NECA (nonselective adenosine analog) in A2AAR knock‐out (A2AKO) and wild‐type (WT) mice. Mice were divided into control (CON) and allergen sensitized‐challenged (SEN) groups, and were sensitized i.p. on days 1, 6 with 20 μg ovalbumin (OVA) followed by 5% OVA aerosol challenges on days 11–13 (n=6 mice per group). Limonene was administered as an inhalation prior to allergen challenges in one group of allergic mice for both WT and KO (SEN+LIM). Whole body plethysmography (measuring airway responsiveness as enhanced pause, Penh) and bronchoalveolar lavage (BAL) studies were performed. Airway responsiveness to MCh (48 mg/ml) in WT SEN group was significantly lowered with limonene treatment (420±92.57% in SEN vs. 56.23±25% in SEN+LIM). However, limonene did not have an effect in A2AKO (553±85% in SEN vs. 588±34% in SEN+LIM). NECA‐induced increased airway responsiveness was attenuated in limonene‐treated WT SEN mice (1002±161 in SEN vs. 250±226%, p<0.05) while no effect was observed in A2AKO groups (541±44% in SEN vs. 528±147% in SEN+LIM). Differential BAL cell analysis showed that limonene reduced levels of eosinophils in WT SEN (70.66±2.6% in SEN vs. 28.66±1.45% in SEN+LIM, p<0.05) while no difference was observed in A2AKO (76.33±1.35% in SEN vs 79±0.69% in SEN+LIM). These data suggest that limonene‐induced reduction in airway inflammation and airway reactivity occurs via activation of A2AAR.Support or Funding InformationLong Island University start‐up funding (DSP)This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Cerebral Blood Flow Responses to a Memory Test in Young and Older Habitual Exercisers
Authors: Carl Alexandra E. , Miller Kathleen B. , Howery Anna J. , Eisenmann Nicole A. , Corkery Adam T. , Barnes Jill N. 
Published: June 2021

In a healthy brain, the cerebral microvessels respond to increased metabolic demand by vasodilating to increase blood flow. Reduced cerebrovascular responses to stimuli are indicative of impaired cerebrovascular functioning, and this mismatch may be a mechanism underlying age‐related reductions in cognition. The purpose of this study was to investigate how the cerebral blood flow (CBF) response to a metabolic stimulus differs between young and older participants. It has been shown that older adults have lower CBF response to chemical stimuli compared to young adults, and we hypothesized there would also be age‐associated differences in the CBF response to metabolic stimuli. We evaluated 15 young (25±1 y) and 11 older (64±1 y) habitual exercisers. Participants were instrumented with a transcranial Doppler ultrasound to measure middle cerebral artery velocity (MCAv) and a Finometer to measure beat‐to‐beat mean arterial pressure (MAP) at baseline and during two difficulty levels of the n‐back memory test. Cerebrovascular conductance index (CVCi) was calculated as MCAv/MAP. There were no group differences in BMI or resting heart rate. The older adults had a significantly higher MAP at rest compared with young adults (96±4 mmHg vs. 86±2 mmHg, respectively; p<0.05). There were no differences in MCAv at baseline. However, baseline CVCi was lower in the older adults compared with young adults (0.55±0.04 cm/s/mmHg vs. 0.70±0.06 cm/s/mmHg respectively; p<0.05). There were no differences in MCAv during either level of the test. During the level 1 test, older adults had higher MAP compared with young adults (111±6 mmHg vs. 96±3 mmHg respectively; p<0.05). During the level 2 test, the older adults again demonstrated augmented MAP compared with young adults (108±5 mmHg vs. 94±3 mmHg; p<0.05). Interestingly, older adults had a greater percent increase in CVCi compared with young adults during the level 2 test (13±3% vs. 7±2% respectively; p<0.05). Thus, while older adults had lower baseline CVCi and lower CVCi during the test, they had a greater increase in CVCi during the higher difficulty test. In summary, there were no age‐associated differences in baseline MCAv or change in MCAv during the cognitive tests, yet MAP was higher in the older adults. Therefore, our results suggest that the CBF response to an acute cognitive challenge is similar in young and older adults, but the regulatory mechanism may be different.Support or Funding InformationSupported by National Institute of Health grant HL118154, and the American Physiological Society Undergraduate Research Excellence Fellowship.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
The Influence of Aging on Central Artery Stiffness and Cerebral Vascular Function Following an Acute Hypertensive Stimulus
Authors: Rosenberg Alexander Jacob , Shroeder Elizabeth C. , Grigoriadis Georgios , Wee Sang Ouk , Griffith Garett J. , Fernhall Bo , Baynard Tracy 
Published: June 2021

Aging decreases cerebral blood flow and increases cerebral pulsatility. High‐intensity resistance exercise (RE) has been shown to acutely increase blood pressure (BP) and reduce cerebral blood velocity (CBv), resulting in greater flow pulsatility in the cerebral circulation, potentially injuring cerebral microvasculature. Understanding the relationship between aging and cerebral blood flow regulation in response to a hypertensive physiological stress (e.g. RE), is important due to its association with increased risk of cerebrovascular events in older adults.ObjectiveTo examine the effect of age on cerebral blood flow dynamics following acute RE in young and older adults.MethodsYoung (n=35, 26 yrs, BMI: 23.8 kg/m2) and older (n=26, 60 yrs, BMI: 30.1 kg/m2) adults performed maximal leg‐extension/flexion RE (3×10 rep), with hemodynamic measurements obtained pre and post‐RE (immediate, 5‐, 30‐min). CBv was measured via transcranial Doppler. Central pulse wave velocity (PWV) was acquired by an automated ambulatory BP cuff. Common carotid artery beta‐stiffness index (β) and blood flow pulsatility were measured by ultrasonography. Continuous beat‐to‐beat heart rate (HR), cardiac output (Q), blood pressure (SBP, DBP, MAP, PP) and end‐tidal CO2 were also measured.ResultsMean and diastolic CBv increased immediately post‐RE in the young (interaction, p<0.05) and decreased below baseline at 5‐min post‐RE (p<0.05) in both groups. Older adults had a greater increase in CBv pulsatility immediate post‐RE (interaction, p<0.05) compared to the young, but continued to rise at 5‐min post‐RE only in the young (interaction, p<0.05). MAP was higher and carotid pulsatility was lower in the older group and increased immediate post‐RE (p<0.05) in both groups. PWV increased immediate post‐RE (p<0.05), and remained elevated at 5‐min post‐RE in the young (interaction, p<0.05). There were no changes in β.ConclusionsImmediately following the cessation of the hypertensive stimulus, an increase in aortic arterial stiffness and BP occurred, accompanied by an increase in carotid and cerebral pulsatility. Despite obtaining higher BP during the stimulus in the older group, mean and diastolic CBv did not increase post‐RE, resulting in greater cerebral pulsatility in older adults. This differential age response indicates reduced cerebral hemodynamic responsiveness to an acute increase in BP with aging.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.