bluuebunny/crossref_metadata_2025_split huggingface dataset:
(−)‐α‐Bisabolol Promotes Neuroprotection on Neuronal Damage, Motor and Memory Deficits Induced by Focal Cerebral Ischemia in Mice
Authors: Fernandes Mara Yone Soares Dias , da Silva Ana Thaís Araújo , Bezerra Jessica Rabelo , Pires Rayssa Costa , Mendonça Rafael Costa , de Andrade Geanne Matos 
Published: June 2021

Brain ischemia pathophysiology involves a complex cascade of events such as inflammation and oxidative stress that lead to neuronal loss and cognitive deficits. (−)‐α‐Bisabolol is a sesquiterpene alcohol obtained from plants such as Vanillosmopsis erythropappa and Matricaria chamomilla, with anti‐inflammatory and antioxidant properties. The present study aimed to investigate the effects of (−)‐α‐Bisabolol (α‐Bis) on neuronal damage and memory deficits induced by permanent middle cerebral artery occlusion (MCAO). Mice were submitted to MCAO and were treated with α‐Bis (50, 100, and 200mg/kg, orally), 3 hours after MCAO and during 4 days. The parameters studied were: infarcted area, memory deficits, myeloperoxidase (MPO) activity, and immunoreactivity for cytochrome C, NF‐κB, and superoxide dismutase (SOD‐2). α‐Bis treatment reduced significantly cerebral infarction, neurological and aversive memory deficits, decreased MPO, and cytochrome c, NF‐κB and SOD‐2 immunoreactivity when compared with MCAO group. Taken together, our study demonstrated neuroprotective effect of (−)‐α‐Bisabolol against ischemia‐induced cerebral injury in mice. We propose that the neuroprotection offered by (−)‐α‐Bisabolol can be attributed, at least in part, to its anti‐inflammatory activity.Support or Funding InformationFUNCAP, UFCThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Modulation of Microglia by P2X and P2Y Receptors
Authors: Campagno Keith , Lu Wennan , Albalawi Farraj , Cenaj Aurora , Tso Huen‐Yee , Mitchell Claire 
Published: June 2021

Microglial cells are involved in a complex series of physiologic and pathophysiologic interactions in the nervous system, and the receptors responsible for mediating these responses are central to coordinating these responses. ATP is a key extracellular signaling molecule in brain and retinal injury, and our previous results indicate release of ATP through pannexin hemichannels following mechanical injury to astrocytes. We ask here whether ATP alters migration, reactivation state and cytokine release in retinal and brain microglial cells. Using a Boyden chamber, ATP was shown to be a powerful chemoattractant for primary microglial cells isolated from both the brain and the retina. Detection of Hoechst‐labeled microglia on the lower side of the chamber peaked after 3 hours. Microglial migration was reduced by exposure of the cells to the P2Y12 antagonist ARC‐69931, while the P2X7 antagonist A839977 had no effect. Exposure of primed microglia to ATP led to the release of IL‐1β. This release was mimicked with P2X7‐specific agonist BzATP, and inhibited with antagonist A839977. Preliminary findings suggest ATP increased markers for the M1‐like activation state and decreasing the M2‐like activation state of microglial cells. Together these data suggest that stimulation of P2 receptors for ATP has a key role to play in migration, cytokine release and reactivate state of microglial cells. We speculate that ATP is a key signaling connection between astrocytes and microglia and helps link mechanical strain to inflammatory signaling in neural tissue.Support or Funding InformationThis work is supported by NIH Grants EY015537 and EY013434, and the Vision Research Core Grant EY001583.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Mutant Huntingtin‐Calmodulin Interaction: Potential Therapeutic Target for Huntington's Disease
Authors: Kapadia Khushboo , Roy Anuradha , McDonald Peter , Klus Nicholas , Frankowski Kevin , Aubé Jeffrey , Muma Nancy 
Published: June 2021

Huntington's disease (HD) is a neurodegenerative disorder caused by an autosomal dominant mutation in the huntingtin (htt) gene. Previous studies in our lab demonstrated that disrupting the binding of mutant huntingtin (mhtt) to calmodulin (CaM) had beneficial effects in cell culture and the R6/2 transgenic animal model. The goal of the current study is to identify and develop small chemical compounds that are non‐toxic and can selectively disrupt the binding of mhtt to CaM. To this end, we employed a high throughput AlphaScreen assay along with counter‐screening assays and identified 481 hit compounds that disrupt the interaction between (His)htt‐CaM(GST). The structures of the hits obtained were analyzed and structurally diverse representative scaffolds were chosen for further development. Analogs of these compounds synthesized from the selected scaffolds were re‐screened in the primary AlphaScreen assay and tested for cytotoxicity. Next, assays were employed to determine if the hits identified in the primary screen can selectively disrupt the mhtt‐CaM interaction without affecting other functions of CaM. The compound selectivity is being determined using two CaM dependent enzymes which are abundantly expressed in neuronal cells and play an important role in neuronal function; Ca+2/CaM dependent death associated protein kinase 1 (DAPK1) and Ca+2/CaM dependent protein kinase 2 gamma (CAMK2ϒ). We have identified numerous compounds that have shown preferential activity in disrupting the (His)htt‐CaM(GST) interaction. Compounds that were non‐toxic and selectively disrupted the binding of mhtt to CaM are tested in cell‐based screening assays to determine if the compounds are protective against deleterious effects of mhtt expression. So far, we have identified two scaffolds that selectively disrupt the binding of mhtt to calmodulin and show protection against mhtt‐induced toxicity. Studies are ongoing to determine if these scaffolds will reduce accumulation of aggregated htt protein and normalize mitochondrial deficits associated with mhtt expression. In the future, these compounds will be tested for their protective effects in animal models of HD. Overall, these studies will aid in identifying compounds that will serve as novel and promising biological probes for drug development in HD.Support or Funding Information1RO1NSO88059This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Dopamine transporter is dysregulated on the peripheral immune cells of drug naïve Parkinson's Disease patients
Authors: Gopinath Adithya , Mackie Phillip , Saadatpour Leila , Doty Andria , Ramirez‐Zamora Adolfo , Streit Wolfgang J. , Okun Michael , Khoshbouei Habibeh 
Published: June 2021

IntroductionParkinson's Disease (PD) is characterized by loss of substantia nigra (SN) dopaminergic neurons, resulting in reduced CNS dopamine transmission. PD is widely thought to start in the periphery; however, whether and how PD affects peripheral dopamine transmission remains unknown. Peripheral immune cells express key dopaminergic proteins, including dopamine transporter (DAT) and tyrosine hydroxylase (TH). Therefore, it is possible that the peripheral dopamine system is affected by PD pathology.ObjectiveWe hypothesized that peripheral immune cells of PD patients exhibit dysregulated dopamine homeostasis.Methods/ResultsUsing flow cytometry we found human peripheral blood mononuclear cells (PBMCs) constitutively express DAT and TH with 90% of CD14+ cells expressing both markers. Upon examining PBMCs of PD patients receiving a variety of treatments, we found that DAT/TH positive PBMCs are elevated in PD patients compared to healthy controls (n=67 independent biological replicates, P<0.05) irrespective of the treatment modality applied. Importantly, in drug naïve patients diagnosed with PD we observed the highest increase in DAT/TH positive monocytes (n=5, P<0.05) compared to both treated PD patients and healthy individuals, suggesting observed changes correlate with disease pathology and not treatment interventions. Collectively, these data suggest a system‐wide dysregulation of the dopamine system on peripheral immune cells in PD. To further understand the functional consequences of increased DAT+/TH+ PBMCs, we asked if DAT function was altered on PD monocyte‐derived cells. Live cell fluorescence microscopy and biochemical analysis confirmed healthy human monocyte‐derived macrophages (MDM) express membrane‐localized, canonically functional DAT (Km=3.2mM). Surprisingly, relative to healthy age‐matched controls, PD patients' MDMs exhibited dramatically elevated DAT‐mediated substrate uptake and increased membrane localization (p<0.0001, n=5 biological replicates).ConclusionsTaken together, these data are consistent with the interpretation that in PD, peripheral dopamine homeostasis is dysregulated. Importantly, this presents PBMC DAT/TH as a potential biomarker for PD and suggests the peripheral dopamine system is functionally linked to the CNS dopamine system. Future work will aim to validate this biomarker and investigate the mechanistic connection between peripheral‐CNS dopamine systems to elucidate the pathophysiological role of dysregulated monocyte dopamine transmission in PD.Support or Funding InformationMcknight Brain Institute; NINDS 0016811This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Dendrobium nobile Lindl. alkaloids alleviate Mn‐induced neurotoxicity via PINK1/Parkinmediated autophagy in SH‐SY5Y cells
Authors: Fu Xiaolong , Wang Xueting , Zeng Ru , Wu Qin , Lu Yuanfu , Shi Jingshan , Zhou Shaoyu 
Published: June 2021

Chronic environmental and occupational exposure to manganese (Mn) results in a progressive neurological disorder referred to as manganism, a syndrome closely resembling Parkinson's disease (PD). The loss of dopaminergic neurons is critically involved in pathological progression of Mn‐induced manganism. Identification of molecular modulators of Mn‐induced neurotoxicity is essential to the development of neuroprotective strategies or effective treatments against Mn manganism. Mitochondrial dysfunction has been increasingly appreciated as a key determinant in Mn induced Parkinsonism. It has been known that PD‐associated mitochondrial proteins, PINK1 and parkin, regulate mitochondrial degradation in the development of neurological disorders. This study was designed to determine whether Dendrobium nobile Lindl. alkaloids (DNLA), a traditional Chinese medicinal herb extract, plays protective function over Mn‐induced neurotoxicity, and to investigate whether the modulation of PINK1/Parkin‐mediated autophagy is involved in the mechanism of DNLA‐mediated cell protection in Mn toxicity. The human dopaminergic cell line SH‐SY5Y cells were utilized as an in vitro model of Mn cytotoxicity. It was found that the treatment of the SH‐SY5Y cells with Mn resulted in concentration‐dependent cell death, accompanied by a decrease in mitochondrial respiration capacity, whereas pretreatment of cells with DNLA significantly alleviated cell toxicity induced by Mn and improved mitochondrial function. Analysis of PINK1 and Parkin expression revealed that pretreatment of the cells with DNLA significantly inhibited the Mn‐elicited decrease in the protein expression levels of PINK1 and Parkin. In addition, the Mn‐treated cells exhibited increased expression of LC3‐II and accumulation of p62, which was noticeably reversed by the pretreatment of cells with DNLA. These results demonstrate that DNLA inhibits Mn induced cytotoxicity, which may be mediated through modulating PINK1/Parkin‐mediated autophagic flux and improving mitochondrial function.Support or Funding InformationThis work was supported by grant from the National Natural Science Foundation of China (Grant No. 81460548).This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Trans‐synaptic regulation of group III mGluR pharmacology by endogenous allosteric modulators implicated in neuropsychiatric disease
Authors: Dunn Henry A. , Dao Maria , Orlandi Cesare , Zucca Stefano , Martemyanov Kirill A. 
Published: June 2021

Functional characterization of the GPCR interactome has focused predominantly on intracellular interacting‐proteins, yet GPCRs are increasingly found in complex with extracellular proteins. Extracellular leucine rich repeat fibronectin type III domain containing 1 (ELFN1) was recently reported to physically anchor mGluR6 and mGluR7 across retinal and hippocampal synapses, respectively; however, the consequence and extent of trans‐synaptic interactions on GPCR physiology and pharmacology had been unknown. We explored the functional implications of ELFN1‐mGluR interactions by developing a novel transcellular GPCR signaling assay platform to monitor changes in mGluR activity in one cell following its exposure to separate ELFN1‐containing cells. Using this platform, we found the first evidence of allosteric modulation of GPCR activity in trans; whereby ELFN1‐expressing cells in co‐culture altered both agonist‐induced and constitutive receptor activity of group III mGluRs expressed in separate cell populations. We further adapted this platform for various readouts and determined transcellular ELFN1‐mediated alterations of group III mGluR cAMP signaling was not a consequence of receptor membrane expression or desensitization, but instead a direct consequence of altered G protein activation as seen by BRET‐based real‐time kinetic assays. Furthermore, we have identified additional trans‐synaptic binding partners of group III mGluRs with previously unknown function and demonstrate selective pharmacological consequence and relevance to neuropsychiatric disease. Our findings demonstrate that accepted principles of group III mGluR pharmacology are critically altered via extracellular interactions with endogenous trans‐synaptic allosteric modulators, and disruption of these interactions may endow susceptibilities to neuropsychiatric disease.Support or Funding InformationThis work was supported by NIH Grants EY018139 and DA026405 (to K.A.M.). H.A.D. is the recipient of a Canadian Institutes of Health Research Postdoctoral Fellowship award.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Establishing the Framework to Evaluate Negative Modulators of Mu Opioid Receptor Signaling in Cells
Authors: Stoveken Hannah M , Wang Dandan , Masuho Ikuo , Grill Brock , Martemyanov Kirill A 
Published: June 2021

Opioid addiction and accidental overdose have arisen as critical health issues as the prevalence and availability of this addicting class of drugs have dramatically increased. The mu opioid receptor (MOR) is the primary analgesic mediator in the brain and is activated by the class of drugs known as opioids. MOR is a G protein coupled receptor (GPCR) that signals through the heterotrimeric G protein class Gi/o. Once activated, the heterotrimeric G proteins transduce the opioid signal to other effectors including adenylate cyclase, voltage‐gated calcium channels, and G protein‐coupled inward‐rectifying potassium (GIRK) channels, among others. Together, this signaling renders the cell less excitable and blocks transmission of pain responses but also elicits unwanted side effects. Endogenously, MOR signaling is regulated to terminate or tune signaling and hence to alter the duration or intensity of the opioid response. Regulators of G protein signaling (RGS) proteins, for example, serve as GTPase‐activating proteins to inactivate Gi/o and terminate MOR signaling. We hypothesized that there may be undiscovered negative MOR regulators that could modulate MOR signaling to lessen opioid side effects. We are currently developing an unbiased forward genetic screen in c. elegans to uncover potential new cell‐autonomous MOR modulators. While the screen is an ongoing effort, we are working to establish the framework for evaluating potential hits in cell‐based assays of MOR signaling. As proof of concept, we examined the effect of the known negative MOR regulator R7BP‐RGS7‐Gb5 complex in cellular assays of MOR function and/or trafficking. Overall, this project is aimed at uncovering and determining the molecular mechanisms of potential new anti‐opioid signaling pathways that could be pharmacologically modulated to mitigate negative opioid‐related side effects.Support or Funding InformationNational Institutes of Health R01 to KMThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Inhibition of CXCR4 signalling and ligand binding by CXCL17
Authors: White Carl W , Pfleger Kevin , Hill Stephen J 
Published: June 2021

CXCL17 is the most recently described chemokine ligand and is highly expressed in mucosal tissues. CXCL17 has been associated with innate responses and acts as a chemoattractant for monocytes and macrophages, but has also been shown to play a role in angiogenesis for tumour development [1]. However currently CXCL17 is poorly characterised, in part, as it signals through a yet unidentified receptor. Initial reports suggested CXCL17 may act as an agonist for the GPCR GPR35 [2], however two recent studies failed to replicate this finding [3,4]. The CXCR4 chemokine receptor is highly expressed in many immune cells that respond to CXCL17. We therefore aimed to investigate if CXCL17 modulates CXCR4‐mediated signalling in model HEK293 cells.Ligand binding and signalling was investigated using NanoBRET assays. For ligand binding HEK293 cells stably expressing Nluc/CXCR4 were incubated for 1 hour with CXCL12‐AF647 (12.5 nM) in the absence or presence of CXCL17 (0.3 nM – 1 μM). For β‐arrestin2 recruitment assays HEK293 cells transiently transfected with CXCR4/Nluc or CXCR4/Rluc8 and β‐arrestin2/Venus were incubated with CXCL17 (0.3 nM – 1 μM) or CXCL12 (10 nM) in the absence or presence of CXCL17 (0.3nM – 1 μM). For G protein activation assays HEK293 cells transiently transfected with Gαi1/Nluc and Venus/Gγ2 were incubated with CXCL17 (1 μM) or CXCL12 (0.1 pM) in the absence or presence of CXCL17 (1 nM – 1 μM). Luminescence was generated by addition of furimazine and changes in BRET following ligand addition was measured between the luciferase and the fluorescent acceptor. Filtered light emissions were measured using a PHERAstar plate reader (BMG).NanoBRET competition ligand binding studies showed CXCL17 inhibited CXCL12‐AF647 binding to Nluc/CXCR4 in a concentration dependent manner (pKi; 6.33 ± 0.33, n=4). In β‐arrestin2 recruitment experiments, CXCL17 resulted in a decrease in constitutive BRET between CXCR4/Rluc8 and β‐arrestin2/Venus (pIC50; 7.24 ± 0.11, n=3) and also inhibited the increase in BRET mediated by exogenous CXCL12 in a concentration dependent manner (pIC50; 6.97 ± 0.21, n=6). Similarly CXCL17 inhibited CXCL12 mediated G protein activation (pIC50; 6.73 ± 0.62, n=4) as well as reducing constitutive CXCR4 mediated G protein activation. CXCL17 did not appear to have agonist effects at CXCR4.This work shows for the first time that CXCL17 is a low affinity inhibitor of CXCR4‐CXCL12 ligand binding, and acts as an inverse agonist of constitutive and CXCL12‐induced CXCR4 signalling.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Extracts of Two Relatively Safe South African Alien Weeds have Synergistic Activity with Conventional Antibiotics against some Urinary Tract Pathogens
Authors: Omokhua Aitebiremen Gift , Van Staden Johannes , McGaw Lyndy Joy 
Published: June 2021

Plants have potential to play a role in the treatment of urinary tract infections, as they contain important bioactive components. These bioactive components may act in synergism with conventional antibiotics which are presently under threat of microbial resistance. They also play a key role in the reduction of oxidative stress. Synergistic activity of dichloromethane, acetone, 70% ethanol, 50% methanol and hot water extracts of the southern African alien weeds Chromolaena odorata and Tithonia rotundifolia combined with gentamicin and amphotericin B was studied using the checkerboard method. Antioxidant activity of the extracts was determined using the quantitative 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) radical scavenging and 2,2′‐azinobis‐(3‐ethylbenzothiazoline‐6‐sulfonic acid) (ABTS) decolorisation methods. The anti‐inflammatory activity was determined through the 15‐lipoxygense enzyme assay. Toxicity screening of the extracts was carried out against Vero monkey kidney, human carcinoma Caco‐2 and human liver C3A cell lines using a colorimetric assay. Synergistic to additive effects were observed among all tested extracts in combination with the conventional antibiotics against all tested strains which are Escherichia coli, Enterococcus faecalis, Klebsiella pneumoniae, Salmonella Typhimurium, Aspergillus fumigatus and Candida albicans. Although the extracts of both plant species had antioxidant activity, the extracts of C. odorata displayed better activity in the ABTS assay with the 70% ethanol extract showing a 50% inhibitory concentration (IC50) of 1.96 μg/mL, better than that of vitamin C (IC50 = 2.027 μg/mL). The dichloromethane extract of T. rotundifolia had better radical scavenging activity in the DPPH assay with an IC50 of 16.231 μg/mL. All the extracts of C. odorata had anti‐inflammatory activity better than that of the positive control quercetin (IC50 = 24.601 μg/mL) except for the acetone extract which was slightly higher (IC50 = 26.098) than the positive control. Lethal concentrations (LC50) of the extracts against Vero, Caco‐2 and C3A cells ranged from 0.78 to 0.96mg/mL, 0.198 to 0.32mg/mL and 0.67 to 0.88 mg/mL respectively, indicating that the extracts are relatively safe in vitro. Results from this study indicate that the extracts of these weedy plant species contain comparatively non‐cytotoxic bioactive compounds that may act in synergy with conventional antibiotics in the treatment of urinary tract infections. Additionally they may reduce oxidative stress and inflammation. Further studies to determine the active component(s) of these weed plants are ongoing.Support or Funding InformationNo fundingThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.