bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pentagalloyl glucose (PGG) Inhibits IL‐1β‐induced pro‐inflammatory cytokine production and matrix metalloproteinase activation in human osteoarthritis synovial fibroblasts
Authors: Haque Mahamudul , Thompson Matthew , Singh Anil , Kopczynski Kelly , Ahmed Salahuddin 
Published: April 2020

Osteoarthritis (OA) is a chronic degenerative joint disease in which the pro‐inflammatory cytokine, interleukin‐1β (IL‐1β), plays a central role in propagating inflammation and cartilage degradation by activating inflammatory mediators and cartilage degrading matrix metalloproteinases (MMPs). In the present study, we evaluated the efficacy of pentagalloyl glucose (PGG), a natural antioxidant, in suppressing IL‐1β‐induced mediators of inflammation and cartilage degradation in human osteoarthritis synovial fibroblasts (OASFs). PGG treatment (0.5–50 μM) for 24 hours had no significant effect on human OASF cell viability (n=3; p<0.01). Analysis of the conditioned media using ELISA showed that PGG (0.5–5 uM/ml) pretreatment significantly inhibited IL‐1β‐induced production of IL‐6 (45–90%), IL‐8 (40–95%), MCP‐1/CCL2 up to 80%, and RANTES/CCL5 by (45–90%) (n=3; p<0.05). In addition, we observed a significant dose‐dependent inhibition in MMP‐1 and MMP‐3 production by PGG in human OASFs (n=3; p<0.05). Furthermore, in‐gel zymography results using conditioned media showed that the enzymatic activity of IL‐1β‐induced gelatinases MMP‐2 and MMP‐9 were markedly reduced upon PGG treatment (n=3; p<0.05). PGG (5 μg/mL) significantly inhibited the degradation of type‐I collagen compared to IL‐1β stimulation alone in human OASFs (n=3; p<0.05). Examination of the mitogen‐activated protein kinase (MAPK) signaling pathway showed that PGG interfered with IL‐1β‐induced ERK1/2 and JNK/SAPK, but not p38 MAPK, to inhibit downstream phosphorylation and nuclear translocation of transcription factor c‐Jun. Immunofluorescence study confirmed that PGG pretreatment inhibits phospho‐c‐Jun and NF‐κB p65 nuclear translocation. Overall, our findings suggest that PGG inhibits IL‐1β‐induced mediators of inflammation and tissue destruction in human OASFs by reducing the activation of MAPK signaling pathway.Support or Funding InformationThis study was supported by the NIH/NIAMS grant R01AR072615 (S.A.), and the Washington State University College of Pharmacy (S.A.), the Summer Undergraduate Research Fellowship from ASPET (M.T.), and Special thanks to Erwin & Jennie Foisy Scholarship Fund (M.H.).
Effect of lighting conditions on thymic mast cells’s response to melatonin intake
Authors: Luzikova Elena , Shatskikh Oksana , Gordova Valentina , Smorodchenko Alina , Sergeeva Valentina 
Published: April 2020

Melatonin is the main secretory hormon of the pineal gland, which plays the fundamental role in neuroendocrine‐immunological network. We have previously shown that melatonin intake at natural light conditions induced the statistically significant changes in the number and state of degranulation of thymic mast cells (MC). The dependence of MC response to melatonin intake under constant dimming conditions has not been studied.Thymuses were isolated from white male mice (2 months old, weight 20–22 g). The animals were divided into 4 groups (each n=20): first control group were for 2 weeks in conditions of constant dimming (with cage illumination per day 0 – 0.5 LUX), mice had free access to drinking water and food); the first experimental group was kept in the same conditions for 2 weeks and received synthetic melatonin «Melaxen» (Unipharm, USA) at a concentration of 4 mg/l with drinking water; the second control group was under dimming conditions for 4 weeks; the second experimental group received melatonin at the same concentration like first group for 4 weeks. One mouse consumed approximately 6 ml of water per day, which equaled 25 mcg of melatonin per day per animal. The thymuses were isolated from the anesthetized animals and embedded in paraffin. Sections 4 microns thick were stained with toluidine blue and methylene blue (Unna), analysed under the microscope (Zeiss Primo Star) and statistically processed by StatSoft Statistica 10.0.The result shows that the keeping of mice under conditions of constant dimming leads to an increase in degranulation of MC in the thymus of both control groups, as well as to up‐regulation of the total MC number in the fourth week of the experiment: in the connective tissue of cortical septum ‐ 1.6 times (p <0.001), in the parenchyma of the thymic lobules ‐ 1.5 times (p <0.05).The intake of melatonin under the constant dimming conditions during 2 and 4 weeks resulted in increasing in the amount of MC in the cortical septum and in the thymus parenchyma by 1.4 and 1.3 times (p <0.05), respectively. The intake of melatonin under constant dimming conditions increase the proportion of MC without degranulation in cortical septa (from 4% to 34% and from 1% to 33%, respectively, for periods of 2 and 4 weeks, p <0.001) and in the thymus parenchyma (from 7% to 39% and from 5% to 36%, respectively, p <0.001) compared with both control groups.Thus, under constant dimming circumstances the thymic MC are more sensitive to melatonin intake compared to the natural light conditions what we reported earlier. Perhaps, the MC prevents the destruction of the thymus and ensures the survival of T‐lymphocytes in the absence of a photoperiod.
Optical Determination of Age‐Related Changes in Subpleural Collagen of Live Human Lungs
Authors: Islam Mohammad Naimul , Jin Guangchun , Bhattacharya Sunita , Bhattacharya Jahar 
Published: April 2020

The impact of age on lung physiology is not known. Collagen is an important determinant of lung structure and function. Therefore, age‐related changes in collagen quantity, geometry and structure can lead to changes in lung function. CT scans of asymptomatic patients reveal age‐dependent increase of subpleural radiologic densities, called interstitial lung abnormalities (ILAs) that predispose to pulmonary fibrosis. However it is not known whether ILAs are collagen deposits that impair alveolar function. Since real‐time fluorescence microscopy (RFI) of the human lung has not been done, we carried out two‐photon and confocal microscopy (2P‐CF) of live, transplant‐reject lungs to determine the age‐related profile of subpleural collagen density (SCD) and whether this affects surfactant secretion. For RFI, we cannulated the bronchus and the artery of the lingular lobe to enable inflation and perfusion. Then, we held the lobe at constant alveolar pressure of 5 cmH2O. To stain alveolar epithelial cells, we subpleurally injected fluorescent dyes by means of a 31‐gauge needle. We detected subpleural collagen as the fluorescence of second harmonics generation (SHG). We quantified subpleural collagen density (SCD) as the integrated collagen fluorescence occurring in the space between the visceral pleura and the alveolar epithelium. To determine surfactant secretion, we quantified the timed appearance of lipid‐sensitive fluorescence in the alveolar space following a transient hyperinflation of the lingular lobe. Our data show that subpleural collagen was evident as well‐defined and evenly spaced cables in young lungs (median age 37 years). By contrast, subpleural collagen in aged lungs (median age 63 years) was marked by poorly formed cables surrounded by diffuse SHG fluorescence. We show that SCDs varied in different regions in all lungs and that SCD was significantly higher in aged than young lungs. Further, in high SCD regions, hyperinflation‐induced alveolar expansion and surfactant secretion were abrogated (p<0.05). Thus, SCDs increase with age and negatively regulate surfactant secretion from adjacent alveoli. SCDs may correspond to ILAs. Our findings raise the novel possibility that a risk‐factor in development of pulmonary fibrosis might be the disruption of alveolar homeostasis caused by age‐related changes in subpleural collagen (HL145547, HL36024).Support or Funding InformationHL145547, HL36024
FXR regulates metabolic function of fat depots during obesity
Authors: Zhou Weinan , Anakk Sayeepriyadarshini 
Published: April 2020

Obesity is a major epidemic and is associated with excess calorie intake leading to adipose tissue expansion and metabolic dysfunction. Farnesoid X receptor (FXR) is a nuclear receptor that transcriptionally regulates lipid and glucose metabolism. Despite several studies revealing FXR expression in the adipose tissue, its exact role in this tissue remains elusive. We determined that both primary pre‐ and post‐differentiated adipocytes from inguinal white (WAT) and brown (BAT) adipose tissue express Fxr transcripts. Notably, adipose‐specific Fxr knockout (Ad‐FxrKO) mice recently generated in our laboratory exhibit glucose intolerance, increased fat accumulation and concomitant reduction in the expression of lipolytic genes in both WAT and BAT when challenged with a high‐fat diet. These data suggest that adipose‐specific FXR may play a crucial role in regulating fat accumulation and subsequent glucose homeostasis during diet‐induced obesity. Since BAT is specialized for non‐shivering thermogenesis by generating heat through uncoupled mitochondrial respiration, we investigated the role for FXR in brown adipocyte mitochondrial function. We found that when Fxr is deleted, genes involved in BAT mitochondrial β‐oxidation, biosynthesis and respiratory chain complex are down‐regulated. Conversely, FXR activation by its endogenous bile acid ligand, chenodeoxycholic acid increases mitochondrial membrane potential of primary differentiated brown adipocytes in vitro, suggesting a key role for FXR in controlling brown adipocyte mitochondrial function and a potential role in thermogenesis. Overall, we demonstrate that FXR can modulate fat break down and regulate mitochondrial functions in the adipose tissue.Support or Funding InformationSupported by R01 DK113080 from NIDDK, and UIUC Start Up Funds.
Mitochondrial Calcium Signaling Tunes Voltage‐Energized ATP Production
Authors: Wescott Andrew P. , Kao Joseph P. Y. , Lederer W. Jonathan , Boyman Liron 
Published: April 2020

How mitochondrial ATP production dynamically responds to cellular metabolic needs is poorly understood. Here we report on quantitative investigations in heart muscle that identify the key molecular and cellular controls of ATP production. We show that Ca2+ influx into the mitochondrial matrix through the mitochondrial calcium uniporter (MCU) is small with no cytosolic Ca2+ threshold and tissue‐specific Ca2+ sensitive gating. MCU controls ATP production by its influence on matrix Ca2+ concentration ([Ca2+]m) which regulates pyruvate and oxoglutarate dehydrogenases and hence Krebs cycle production of NADH. The NADH level affects the voltage‐gradient across the inner mitochondrial membrane (Δψm) which in turn regulates ATP synthase. Our first report of the voltage‐dependence of ATP synthase in mammalian system is determined by measuring its ATP production. By this means, we show that the Δψm dependence of ATP synthase is different from the previous “gold standard”, the voltage‐dependence of bacterial ATP synthase. Additionally, we show how ATP production in cardiac mitochondria depends on both [Ca2+]m and on cytosolic [ADP]. Higher heart rates and contraction under load increase both Ca2+ sensitive and Ca2+ insensitive ATP production. These findings provide a new and different understanding of how mitochondria generate ATP in response to metabolic need, how ATP production is powered by Δψm, and how Δψm is regulated by mitochondrial Ca2+ signaling.Support or Funding InformationThis research was supported by American Heart Association grants SDG 15SDG22100002 (to L.B.) and 16PRE31030023 (to A.P.W.); by NIH R01 HL106056, R01 HL105239, U01 HL116321, 1R01HL142290, 1 R01 HL140934 and 1R01 AR071618 (to W.J.L.); by the Medical Scientist Training Program and Training Program in Integrative Membrane Biology, NIH 2T32GM092237‐06 and 5T32GM008181‐28 (to A.P.W.).
Regulation of alpha‐Arrestin Function in G Protein‐Coupled Receptor Signaling and Trafficking
Authors: Wedegaertner Helen , Pan Wen-An , Trejo JoAnn 
Published: April 2020

The ubiquitously expressed β‐arrestins are known to play key roles in regulating G protein‐coupled receptor (GPCR) desensitization, internalization, and signaling. Humans also express a newly discovered family of arrestins, termed α‐arrestins, whose function remains poorly understood. While β‐ and α‐arrestins share minimal sequence homology, they are predicted to be structurally similar, except that β‐arrestins contain clathrin motifs within their C‐tails, which are known to be important in facilitating receptor internalization, and α‐arrestins contain PPxY motifs in their C‐tails, which are known to recruit WW‐domain containing proteins, such as Nedd4‐family E3 ubiquitin ligases. This suggests a separate role for α‐arrestins, although they may be subject to similar regulatory mechanisms, including phosphorylation, ubiquitination, and conformational change. Additionally, yeast, which do not express β‐arrestins, express arrestin‐related trafficking adaptors (ARTs), which are predicted to be structurally similar to human arrestins and contain PPxY motifs. ARTs have been well‐characterized as key regulators of receptor trafficking in yeast and are also regulated through post‐translational modification. Recently, we demonstrated a role for arrestin domain‐containing protein‐3 (ARRDC3), a mammalian α‐arrestin, in regulating trafficking of protease‐activated receptor‐1, a GPCR for thrombin. However, while GPCR regulation of β‐arrestin function has been well characterized, it remains entirely unknown how GPCRs regulate α‐arrestins, such as ARRDC3, or how such regulatory mechanisms might impact α‐arrestin function. Here, we examine how PAR1 signaling regulates ARRDC3 function in facilitating PAR1 trafficking. Using a variety of biochemical and microscopy‐based techniques, we show that PAR1 may regulate ARRDC3 through modulation of post‐translational modifications, and that identified ARRDC3 regulatory domains may play a role in regulating ARRDC3 function through controlling its subcellular localization and recruitment of interaction partners. We additionally will use a variety of approaches to elucidate the role of ARRDC3 regulatory mechanisms in PAR1 trafficking and signaling. Additionally, ARRDC3 has been identified to be a tumor suppressor in invasive breast cancer, functioning at least partially through its role in controlling PAR1 signaling and trafficking. Therefore, the results of these studies will not only advance our understating of how α‐arrestins are regulated but may also lead to the identification of novel therapeutic targets to prevent or treat invasive breast cancer.Support or Funding InformationUCSD Graduate Training Program in Cellular and Molecular Pharmacology through NIH General Medical Sciences, T32 GM007752 and by National Institute of Health NIGMS R01 GM090689 and R35 GM127121 (JoAnn Trejo)
IGFBP‐3 Blocks Hyaluronan‐CD44 Signaling, Affecting Acetylcholinesterase Levels in A549 Cell Media and Cell Viability
Authors: Price Deanna , Muterspaugh Robert , Clegg Bradley , Williams Asana , Stephens Alexis , Guthrie Jeffrey , Heyl Deborah , Guy-Evans Hedeel 
Published: April 2020

Insulin‐like growth factor binding protein‐3 (IGFBP‐3) belongs to a family of six IGF binding proteins. We previously found that IGFBP‐3 exerts its cytotoxic effects on A549 (p53 wild‐type) cell survival through a mechanism that depends on hyaluronan‐CD44 interactions. To shed light on the mechanism employed, we used CD44‐negative normal human lung cells (HFL1), A549, and H1299 (p53‐null) lung cancer cells. A synthetic IGFBP‐3 peptide (215‐KKGFYKKKQCRPSKGRKR‐232) but not the mutant (K228AR230A), was able to bind hyaluronan more efficiently than the analogous sequences from the other IGFBPs. In a manner comparable to that of the IGFBP‐3 protein, the peptide blocked HA‐CD44 signaling, and more effectively inhibited viability of A549 cells than viability of either H1299 or HFL1 cell lines. Treatment with the IGFBP‐3 protein or its peptide, affected acetylcholinesterase activity in the A549 cell media but not in the media of either HFL1 or H1299, an effect that correlated with changes in cell viability. These effects were diminished upon the same treatment of A549 cells transfected with either p53 siRNA or acetylcholinesterase siRNA. Taken together, our results show that IGFBP‐3 or its peptide blocks hyaluronan‐CD44 signaling via a mechanism involving p53 and acetylcholinesterase.Support or Funding InformationResearch reported in this work was supported by the National Institute of General Medical Sciences of the National Institutes of Health under Award Number R15GM131222 to Hedeel Guy Evans.
CYTOTOXIC POTENTIALS OF METHANOL EXTRACTS OF EKLONIA RADIATA AND JANIA VERUCOSA IN DIFFERENT CANCER CELLS AND NON‐CANCEROUS CELL LINE.
Authors: SAIBU GBEMISOLA MOROUNKE , Nakin Motebang Dominic , Oyedeji Adebola Omowunmi , Oyedeji Opeoluwa , Meyer Mervin 
Published: April 2020

IntroductionFinding novel anticancer agents is very important for cancer treatment. Marine organisms are valuable source for developing novel agents for clinical applications. Seaweeds have been shown to have several biological activities, including anticancer activity. This study aimed at evaluating the cytotoxicity potentials of methanol extracts of Eklonia radiata (ER) and Jania verucosa (JV).Materials and MethodsIn this study, a panel of three cancer cell lines (HepG2, MDA and CaCo2) and one non‐cancerous cell line (KMST‐6) were treated with methanol extracts of Eklonia radiate (ER) and Jania verucosa (JV). Both ER and JV were found on rocky shores of the Eastern coast of South Africa, ER belongs to Kelp family while JV belongs to Corallinaceae family. The cells were treated with various concentrations of methanol extracts of ER and JV for 24 hrs, the percentage viability values of the cells were determined by the tetrazolium salt reduction assay (MTT).ResultsMorphological alteration of the cell lines after exposure with methanol extracts of Ecklonia radiata (ER) and Janica verucosa (JV) were observed under phase contrast microscope. The cytotoxicity result showed that cells treated with both methanol extracts of ER and JV had more cytotoxicity effect on MDA treated cells followed by HepG2 and Caco2. Non‐cancerous cell line (KMST‐6) however showed some selectivity in their activities.ConclusionsSeaweeds generally change estrogen metabolism. However, in this present study, it can be established that both Eklonia radiate (ER) and Jania verucosa (JV) had potential for chemoprevention of human breast and this can be considered as potential sources of anticancer agent. Further studies are necessary for isolation and identification of biologically active substances present in these extracts.
The Emerging Role of C‐peptide on Immune Cells
Authors: Bunn Marcus , Pinger Cody , Spence Dana 
Published: April 2020

Diabetes affects 30 million individuals in the U.S. today. Approximately 10% of these cases are type 1 diabetes (T1D). T1D is an auto‐immune disease that destroys the insulin‐producing cells of the pancreas (β‐cells), resulting in increased levels of blood glucose (hyperglycemia). Consequently, people with T1D suffer from many vascular health complications, such as nephropathy, neuropathy, retinopathy, and cardiovascular disease. In addition, individuals with T1D are immune deficient. It is hypothesized that hyperglycemia effects the expression of glucose transporter 1 (GLUT1), a known glucose transporter of circulating blood cells including immune cells. This could lead to important immune cells residing in an energy deficient state.C‐peptide is a 31‐chain amino acid peptide co‐produced with insulin in the pancreatic β‐cells. Previous work from our group has shown that C‐peptide increases glucose absorption into, and ATP release from, red blood cells (RBCs). However, we have also shown that for C‐peptide to interact specifically with RBCs to elicit a biological response, it must be co‐administered with Zn2+ and albumin. Here, we measured the interaction between C‐peptide and immune cells (Tcells and neutrophils) in the presence or absence of Zn2+ and albumin. We also investigated Zn2+ binding to T‐cells and neutrophils in the presence or absence of C‐peptide and albumin. Furthermore, we studied the effect of C‐peptide on immune‐cell activation by performing functional studies to measure cell adhesion and migration. These functional studies were enabled by a novel 3D‐printed in vitro model system.T‐cells and neutrophils were collected from whole blood samples from consenting adults and separated from other cell types by immunomagnetic separation. Immune cells were incubated with varying combinations of C‐peptide, Zn2+, and albumin. C‐peptide binding was determined using enzyme‐linked immunosorbent assay (ELISA). Zn2+ binding was determined radiometrically using 65Zn2+, and radiation was counted using a gamma counter. Cellular adhesion and migration assays will be quantified using fluorescence spectroscopy. Our results preliminarily suggest that albumin is required for delivery of C‐peptide, but not Zn2+. With albumin present we show 2.0 × 104 C‐peptide molecules bound per neutrophil. Interestingly, when albumin is absent, we observed no significant binding of C‐peptide to neutrophils. However, there appears to be additional Zn2+ added to the neutrophils when in the presence of both the albumin and C‐peptide system, suggesting a specific binding site for both on the neutrophil. Nearly identical numbers were observed for C‐peptide binding to T‐cells.Support or Funding InformationNIH
(‐)‐Epicatechin Activates Pregnane X Receptor (PXR) in Skeletal Muscle
Authors: Ortiz Miguel , Najera Nayelli , Villarreal Francisco , Ceballos Guillermo 
Published: April 2020

(‐)‐Epicatechin (EC) is a flavanol that has shown numerous biological effects such as: decrease cardiovascular dysfunction risk, metabolism regulation, induction of skeletal muscle (SkM) cells differentiation among others. The EC‐induced effects involve its interaction with acceptor/receptor like molecules and seem to be specific. The described EC acceptor/receptor molecules do not explain at all the EC’s effect on SkM. Based on structural similitude between EC and steroidal backbone, we decided to search for proteins that can recognize/interact with steroids and which activation/deactivation leads to similar effects as those induced by EC. The pregnane X receptor (PXR) can fulfill those characteristics; although the main function of this receptor is xenobiotics depuration, it is also linked to metabolism regulation and cell proliferation due to its transcription factor function. Taking as main objective the evaluation of a possible EC‐PXR interaction, docking assays were performed in order to establish if affinity exist between both molecules and if the interaction is comparable with a known agonist: pregnenolone‐16‐carbonitrile (PCN). To confirm the affinity of EC from PXR, this receptor was isolated from rat’s skeletal muscle homogenate using affinity chromatography with a column which has the flavanol attached. Similarly, the activation of PXR by (‐)‐Epicatechin was evaluated in vitro; cultured C2C12 cells (mouse myoblast) were stimulated with 0.1μM of EC or 0.1μM of PCN in order to see the expression of Cyp3a11 (a downstream gene promoted by PXR); the effect was blocked with 1μM of the antagonist Ketoconazole. The results reported here demonstrated that (‐)‐Epicatechin could interact and activate PXR.Support or Funding InformationConacyt 253769