bluuebunny/crossref_metadata_2025_split huggingface dataset:
Neuroprotection via LRP‐1 Signaling in the Retina of Diabetic Mice
Authors: El‐Desoky Dalia Hany , Sherman Josiah , Freter Robert , Adams Ryane , Mbony Hannah , Joeseph Tiffany , Heron David , Hossain Ahamed , Bhattacharjee Partha S. 
Published: June 2021

Neuronal pathologies in the retina precede clinically evident vascular abnormalities associated with diabetic retinopathy (DR). Critical barriers to the development of adequate therapeutic strategies for the treatment of DR stem from the lack of information regarding the mechanism of early retinal neurodegeneration and its progression to late vascular abnormalities. While the early loss of neurons remains clinically undiagnosed, color blindness, lack of contrast sensitivity and abnormal electroretinogram characteristic to retinal neurodegeneration are well documented. In fact, diabetes‐induced retinal neurodegeneration precedes vascular damage. Two hallmark features of retinal neurodegeneration are neuronal (retinal ganglionic cell‐RGC) apoptosis and Müller cell (regulator of neuronal homeostasis) hyperactivity. Our studies with genetically modified db/db (mimicking human type 2 diabetes mellitus) mice, suggests a neuroprotective signaling pathway involving low‐density lipoprotein receptor‐related protein‐1 (LRP‐1). Our in vivo studies suggest that LRP‐1 activation reduces neuronal cell apoptosis in the retina through inhibition of cytoplasmic protein phosphate and regulation of PI3k/Akt and Erk1/2 pro‐survival pathways. Isolating pure RGC cultures from neonatal mice for in vitro analysis excluded the effects of non‐neuronal retinal cell regulation. Specifically, our recent data suggest that in vitro treatment of RGC using one small peptide (apoEdp) mimicking the LRP‐1 binding region of human apolipoprotein E results in reduced glutamate excitotoxicity. We suggest a new therapeutic strategy of reducing neuronal apoptosis in the diabetic retina that may benefit as an interventional approach to other retinal neurodegenerative diseases such as glaucoma and age‐related macular degeneration (AMD).Support or Funding InformationSupport is provided in part by grant number 2T34GM007716‐38 from the National Institute on Minority Health and Health Disparities (NIMHD), National Institutes of Health (NIH), Department of Health and Human Services (DHHS) and its contents are solely the responsibility of the authors and do not necessarily represent the official views of NIMHD or NIH. Support is also provided in part by Maximizing Access to Research Careers (MARC).This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Discovery and characterization of a novel series of D2 dopamine receptor‐selective antagonists though iterative chemistry of a BET bromodomain inhibitor
Authors: Fearce Chelesa T. , Donegan Megan C. , Day Marilyn M. , Yoshioka Makoto , Strovel Jeffrey W. , Free R. Benjamin , Sibley David R. 
Published: June 2021

Recent findings by several groups have highlighted the potential for targeting D2 dopamine receptors (D2R) in cancer pharmacotherapy. In addition to being an important therapeutic target for psychiatric disorders (all current FDA‐approved antipsychotics are D2R antagonists), it has been proposed that D2Rs are over‐expressed in several types of cancer and that D2R inhibition is associated with anti‐proliferative effects. In developing therapeutic compounds which target bromodomain (BET) proteins (well‐known cancer targets whose inhibitors are known to synergize with multiple classes of drugs), we have found compounds that unexpectedly exhibited both BET inhibition and D2R antagonism. The lead compound, CG250, displays high affinity for BET (~32 nM) as well as the D2R (~80 nM) and ~50‐fold selectivity vs. the D3R and D4R in radioligand competition binding assays. These initial findings of moderately selective D2R antagonism within this core scaffold led us to develop other analogs around this series to examine D2R selectivity. A library of CG250 analogs (~100 compounds) were synthesized to examine the structure‐activity relationships underlying D2R‐antagonism. This library was analyzed for D2R, D3R, and D4R binding activities using competition radioligand binding assays, functional signaling readouts (β‐arrestin recruitment and cAMP inhibition), and BET inhibition. These analogs had varying potencies for D2R antagonism and BET inhibition, including some analogs that were selective for one activity or the other. Lead analog CG14274 displayed high affinity for the D2R (<100 nM) and >400‐fold selectivity vs. the D3R in competition binding and β‐arrestin recruitment assays. Functional profiling of the CG14274 scaffold against a large (168) panel of diverse GPCRs revealed global selectivity in that it was only active in antagonizing a D2R‐mediated response. Given the striking selectivity and potency of CG14274, further development and a focused medicinal chemistry campaign of this lead compound is warranted. Optimization of this series will allow for rational drug design strategies that may result in the development of novel D2R‐selective antagonists or dual BET/D2R inhibitors for the treatment of psychiatric disorders and/or cancer.Support or Funding InformationNINDS IRPThis abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Investigating the Interactions of GRK2 with a G‐protein Signaling‐Biased D2 Dopamine Receptor
Authors: Willette Blair K.A. , Soto Marta Sanchez , Gonye Elizabeth C. , Mortiz Amy E. , Free R. Benjamin , Sibley David R. 
Published: June 2021

D2 dopamine receptors (D2Rs) are a part of the G protein‐coupled receptor (GPCR) superfamily, and have been linked to the etiology and/or therapy of numerous neuropsychiatric disorders, such as Parkinson's disease and schizophrenia. While the D2R is a highly validated drug target, the receptor signals through multiple pathways, some of which may result in adverse side effects in patients. Signaling‐biased agents that selectivity stimulate, or block, specific D2R‐mediated pathways could represent improved therapeutics. We recently identified a G‐protein signaling‐biased D2R agonist (MLS1547) that has minimal ability to recruit β‐arrestin. Molecular modeling of MLS1547‐D2R interactions revealed a key residue, F189, at the interface between the fifth transmembrane segment (TM5) and the second extracellular loop that is involved in the biased signaling properties of MLS1547. We mutated this residue in the D2R (F189A) and found, using a variety of signaling assays, that this mutation prevents the recruitment of β‐arrestin with minimal effects on G protein signaling, i.e., the F189A D2R is a G protein signaling‐biased mutant. To investigate the mechanisms of this biased signaling we explored the interactions of the wild‐type D2R and F189 mutant with G‐protein coupled receptor kinase 2 (GRK2), which has been shown to phosphorylate the D2R. Initially, we found that over‐expression of GRK2 can enhance the ability of dopamine to recruit β‐arrestin to the WT receptor. Similarly, using a GRK2‐D2R BRET assay to directly assess D2R‐GRK2 interactions, we found that dopamine stimulation increases GRK2‐D2R interactions. Surprisingly, we found that the F189A D2R mutant is unable to recruit GRK2 upon agonist activation suggesting that GRK2‐D2R interactions may be linked to recruiting β‐arrestin. In another series of experiments, we sought to determine if these effects of GRK2 are mediated by receptor phosphorylation. We examined agonist‐induced β‐arrestin and GRK2 recruitment using previously described phosphorylation‐defective D2R mutants (Namkung et. al., JBC 284:34103, 2009). Interestingly, we found that the D2R phosphorylation‐null mutants were not impaired in their ability to recruit either GRK2 or β‐arrestin – in fact, β‐arrestin recruitment and receptor internalization were actually enhanced. These results suggest that GRK2‐D2R interactions may play a critical role in regulating the biased signaling properties of the D2R, but not through phosphorylation of the receptor. Further, GRK2 may enhance β‐arrestin recruitment by mechanisms other than D2R phosphorylation.Support or Funding InformationNINDS IRPThis abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Striatal ERK is Activated in Response to L‐DOPA Administration in a Knock‐in Mouse Model of DOPA‐Responsive Dystonia
Authors: Briscione Maria , Donsante Christine , Fan Xueliang , Campbell Simone , Bernhard Douglas , Downs Anthony , Gutman David , Sardar Tejas , Shannon Alec , Sutcliffe Diane J. , Jinnah H.A. , Hess Ellen J. 
Published: June 2021

Abnormal dopamine (DA) neurotransmission is associated with many dystonic disorders; however, the precise nature of the defects in DA transmission that result in dystonia are not known. To address this question, we used a knock‐in mouse model of L‐DOPA‐responsive dystonia (DRD). DRD mice display the core features of the human disorder, including reduced striatal DA levels and abnormal movement that improves in response to L‐DOPA, the precursor to DA. In the striatum, DA promotes movement by activating D1 receptors (D1Rs) expressed on direct pathway spiny projection neurons (SPNs) and inhibits movement by activating D2 receptors (D2Rs) expressed on indirect pathway SPNs. D1Rs stimulate adenylate cyclase (AC) activity and D2Rs inhibit AC; however, in DRD mice, D1Rs display an exaggerated AC response to D1 agonist stimulation and D2Rs exhibit a change in valence whereby D2R agonists increase AC. Our objective was to determine signaling alterations in both SPN subtypes downstream of AC, specifically phosphorylated ERK (p‐ERK), that contribute to the alleviation of dystonia by L‐DOPA to identify downstream targets that may serve as novel therapeutic targets. DRD and control mice were subcutaneously injected with L‐DOPA (10 mg/kg), the D1R agonist SKF 81297 (0.2 mg/kg), the D2R agonist quinpirole (0.1 mg/kg), or saline. Mice were perfused 45 min after drug treatment and striatal sections were immunostained for p‐ERK. DRD mice showed a significant and robust increase in p‐ERK levels in the dorsal striatum in response to L‐DOPA treatment compared to controls and saline‐treated mice. In contrast, SKF 81297 or quinpirole treatment evoked only modest changes in p‐ERK. The L‐DOPA specific increase in p‐ERK suggests that D1R and D2R co‐activation may regulate p‐ERK and/or that p‐ERK may serve as a coincidence detector for convergent DA and glutamatergic signaling that occurs when endogenous DA signaling is restored in the striatum. Future studies are aimed to elucidate cell‐type specific mechanisms underlying increased p‐ERK in response to L‐DOPA in DRD mice to refine downstream signaling mechanisms that are instrumental to the therapeutic effects.Support or Funding InformationThis work was supported by the United States National Institute of Health grant R01 NS088528 and T32 NS007480‐17.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Gene Activity and Cell Mechanics during Drosophila Embryonic Development
Authors: Wieschaus Eric 
Published: June 2021

During development, cells in an embryo face two major tasks. First they must express distinct combinations of genes appropriate for specific cell fates such as muscle and skin. Once such patterns of gene expression are established, cells must change their shape and position to match those cell fates. These morphological transformations are remarkable for their speed and precision, but also for their incredible beauty. The associated cell shape changes depend on local patterns of gene activity, but how such patterns are converted into the physical properties controlling shape and motility is a major unanswered question in biology. We have approached these problems in Drosophila, where large scale mutagenesis screen have provided a detailed description of the gene activities that pattern cells in the embryo. Our initial analyses focused on the internalization of mesoderm cells during gastrulation and their subsequent epithelial to mesenchymal transition. Our genetic analyses are coupled with quantitative imaging in living embryos and experimental manipulations designed to measure physical parameters such as cytoplasmic viscosity and elastic lifetimes of the cell cortex. In one approach, we use a computational vertex model where passive volume maintenance in cells bounded by an elastic cellular membrane can account for invagination of the furrow. The second approach eliminates the role of elastic cell membranes and relies on Stokes equation to explain the invagination in terms of global flows in viscous cytoplasmic medium. A surprising feature of all morphological changes in Drosophila is that although they are driven by gene activities in individual cells, they can often be understood as global changes in the distribution of physical forces within the entire tissue. These finds open up a new perspective on the relationship between cells and organismal morphology.Support or Funding InformationHoward Hughes Medical InstituteThis abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
The polybrominated flame retardant BDE‐47 increases steroidogenesis and alters mitochondrial activity and morphology in the HAC15 human adrenocortical cell line
Authors: Sharthiya Harsh , Schupbach Chad , Kopf Phillip , Dineley Kirk , Malaiyandi Latha 
Published: June 2021

Polybrominated diphenyl ethers (PBDE) are a class of flame retardants with wide industrial and domestic use that are known to disrupt endocrine function. Because of their long half‐life in the environment and ability to bioaccumulate in fatty tissues, there is significant interest in understanding their long‐term effects on human health. Our research investigates the effects of a particular PBDE, BDE‐47, in a steroid‐producing human adrenocortical carcinoma cell line (HAC15). We found that BDE‐47 exposure in HAC15 cells significantly increases aldosterone and cortisol production. Furthermore, BDE‐47 increased both ATP levels and the activity of mitochondrial cytochrome c oxidase subunit 1, but the activities of glycolytic enzymes (hexokinase, phosphofructokinase and pyruvate kinase) were unchanged. Sublethal concentrations of BDE‐47 caused overt morphological changes by producing shorter and rounded mitochondria. These studies will further investigate mitochondrial pathways that contribute to increased steroid synthesis in adrenal cortical cells and will help elucidate the long‐term effects of flame retardants on human cardiovascular health.Support or Funding InformationSupported by Midwestern University intramural funding.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Activation of NLRP3 Inflammasomes in Non‐alcoholic Steatohepatitis: A Novel Molecular Target of FTZ Remedy for Metabolic Syndrome
Authors: chen yu , He Xinxiang , Yuan Xinxu , Hong Jinni , Li Pinlan , Guo Jiao 
Published: June 2021

NLRP3 inflammasome activation not only serves as an intracellular machinery triggering inflammation, but also produces uncanonical effects beyond inflammation such as changing cell metabolism, inducing cell transformation and increasing cell membrane permeability. The present study was designed to test whether this NLRP3 inflammasome activation plays a crucial role in the ‘two‐hit’ injury during non‐alcohilic steatohepatitis (NASH) and whether this inflammasome can be a therapeutic target for the action of Fufang Zhenzhu Tiaozhi (FTZ), a widely used herbal remedy for metabolic syndrome in China. By confocal microscopy, oil red O staining and immunohistochemistry, we demonstrated that NLRP3 inflammasomes formation and activation as well as lipid deposition occurred in the liver of mice on the high fat diet (HFD), as shown by increased NLRP3 components colocalization, enhanced production of IL‐1b and HMGB1, and remarkable lipid deposition in liver cells. FTZ extracts were found to not only significantly reduce the NLRP3 inflammasome formation and activation (from 1.46&1.81 to 1.01&1.29 folds of control), but also attenuated the liver steatosis (from 41.13% to 17.96%). In in vitro studies, palmitic acid (PA) was used to induce NLRP3 inflammasome activation and lipid deposition in hepatic stellate cells (HSCs). It was found that PA increased colocalization of NLRP3 components and enhanced cellular caspase‐1 activity (to 2.28 folds of control), indicating the formation and activation of NLRP3 inflammasomes. PA also increased HMGB1 production and enhance the lipid deposition in these cells. In FTZ treated cells, not only inflammasome activation was attenuated (from 1.78&1.81 to 1.01&1.07 folds of control, respectively), but also lipid deposition in HSCs was blocked, which was similar to the effects of GLY, an HMGB1 inhibitor (from 18.87% to 0.46%&4.29%, respectively). Mechanistically, we found that PA stimulated O2.− production (to 2.71 folds of control) to activate NLRP3 inflammasomes in HSCs, which was blocked by FTZ treatment as did by NAC, a O2.− scavenger (to 0.86 and 1.33 folds of control, respectively). It is concluded that NLRP3 inflammasomes formation and activation may contribute to the development of both lipid deposition and inflammation during NASH and that FTZ inhibits NASH by its action on both inflammatory response and liver lipid metabolism associated with NRLP3 inflammasome activation.Support or Funding Informationsupported by NSFC grants (81530102 to J. G) and NIH grants (HL057244 and HL075316 to P.L.)This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Formyl peptide receptor 1 signalling promotes experimental colitis in mice
Authors: Fusco Roberta , Di Paola Rosanna , Gugliandolo Enrico , D'Amico Ramona , Perretti Mauro , Cuzzocrea Salvatore 
Published: June 2021

Inflammatory bowel disease is characterised by intricate immune cell interactions with tissue cells and such cross‐talks can become deregulated. The formyl peptide receptor 1 (Fpr1) is expressed by both immune and stromal cells including epithelial cells. We evaluated the development of the physiopathology of the DNBS induced colitis in Fpr1 KO mice compared to WT animals. We have assessed both macroscopic and histological markers of the diseased, together with the immunohistochemical and molecular changes. DNBS‐treated Fpr1 KO mice showed a i) reduction in weight loss, ii) lower extent of colon injury and iii) an increase in MPO activity. Molecular analyses indicated that in absence of Fpr1 there was reduced NF‐κB translocation into the nucleus and FOXP3 and GATA3 expression as well as a dysregulation of TGF‐β signalling. In addition, the colon of DNBS‐injected Fpr1 KO mice displayed a lower degree of expression of Bax and higher expression of Bcl‐2 compared correspondent WT mice. Finally, intravital microscopy investigation of the microcirculation post‐DNBS instillation revealed a lower degree of neutrophil‐endothelial cell rolling and adhesion ‐ mediated by P‐selectin and ICAM‐1 – in Fpr1 KO mice. All the main outcome in the study have a P‐value, statistical significance of evidence, less than 0.05. We provide evidence for an important pathogenic role of mouse Fpr1 in experimental colitis, an outcome effected through modulation of immune cell recruitment together with a modulation of local cellular activation and survival.Support or Funding InformationNo foundingThis abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
The effects of a metformin – methylglyoxal metabolite on endothelial cell function.
Authors: Nguyen Huong T. , Hargraves Tiffanie , Lau Serrine , Monks Terrence 
Published: June 2021

Reactive dicarbonyls, such as methylglyoxal (MG), are elevated in type‐two diabetes mellitus (T2DM) patients. These endogenous electrophiles covalently modify proteins, which may contribute to diabetic complications. For example, endothelial dysfunction is an early marker of atherosclerosis and other cardiovascular complications associated with T2DM. Dysfunction is characterized by a reduction in the bioavailability of vasodilators, particularly nitric oxide (NO), and/or an increase in apoptosis. Metformin is the first‐line therapy for T2DM and significantly reduces adverse diabetic endpoints and mortality more effectively than other anti‐hyperglycemic agents. In particular, metformin exhibits cardiovascular protective activity, the mechanism(s) of which remain unclear. We have shown that metformin scavenges MG to form an imidazoline metabolite, ([E]‐1,1‐dimethyl‐2‐[5‐methyl‐4‐oxo‐4,5‐dihydro‐1H‐imidazol‐2‐yI]guanidine; IMZ), which may contribute to the therapeutic effects of metformin. We hypothesized that IMZ may exhibit protective effects on cardiovascular complications by improving endothelial cell function. Primary human umbilical vein endothelial cells (HUVEC) were therefore treated with different concentrations of IMZ (1μM, 1nM, 1pM). Intracellular levels of NO were measured by confocal microscopy using DAF‐FM diacetate dye, and western blot was used to determine the phosphorylation status of key proteins involved in prosurvival signaling pathways, such as Akt, ERK1/2 and the phosphorylation of eNOS. IMZ treatment increased intracellular NO levels in HUVEC cells, concomitant with an increase in the activation of eNOS, as observed by western blot analysis. In addition, when HUVEC cells were treated with IMZ (1pM to 1uM), there was a significant increase in the levels of phospho‐AKT and phospho‐ERK1/2. This activation was time‐dependent, with peak activation occurring between 10 to 20 minutes. Moreover, phosphorylation of eNOS, Akt and ERK1/2 was inhibited by pretreatment of cells with imidazoline 1 receptor (I1R) and alpha‐2 receptor (α2R) antagonists. Collectively, these results demonstrate that IMZ might have protective effects on endothelial function by activating I1R and/or α2R. Studies are ongoing to further elucidate the effects of IMZ on stress‐induced endothelial dysfunction.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Effect of Infliximab and Tocilizumab on Fructose Induced Hypertension and Insulin Resistance in Rats
Authors: Ali Badreldin H. , Suleimani Yousuf M. , Abdelrahman Aly M. 
Published: June 2021

We investigated the possible protective effect of infliximab (INF), a tumor necrosis factor alpha (TNF‐α) inhibitor and tocilizumab (TOC), an interleukin‐6 (IL6) inhibitor on fructose induced hypertension and insulin resistance in rats. Rats were fed a 60% fructose diet for 8 weeks in the absence or presence of INF (5 mg/kg, i.p., weekly) or TOC (8 mg/kg, i.p., every two weeks) for 4 weeks. Fructose increased blood pressure, plasma insulin, HOMA‐IR, triglycerides, cholesterol, uric acid, aspartate aminotransferase (AST), urea, creatine kinase (CK), nitric oxide and aortic endothelin. Both INF and TOC attenuated fructose induced increase in blood pressure, insulin resistance, plasma nitric oxide and uric acid. TOC reduced the increase in triglycerides and cholesterol. Both drugs did not affect the increase in CK, AST or urea. INF reduced aortic endothelin. Our results showed that both INF and TOC were partially successful in reversing fructose ‐ induced changes.Support or Funding InformationThis work was supported by a grant from Sultan Qaboos University (IG/MED/PHAR/16/02)This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.