Neurotrophin signalling in health and disease

2006 ◽  
Vol 110 (2) ◽  
pp. 167-173 ◽  
Author(s):  
Moses V. Chao ◽  
Rithwick Rajagopal ◽  
Francis S. Lee
Keyword(s):  
Well Being ◽  
Receptor Activation ◽  
Trophic Factors ◽  
Receptor Ligands ◽  
Transmembrane Receptors ◽  
Disease States ◽  
Polypeptide Growth Factors ◽  
Neurotrophin 3 ◽  
Health And Disease ◽  
G Protein Coupled

Neurotrophins are a unique family of polypeptide growth factors that influence the proliferation, differentiation, survival and death of neuronal and non-neuronal cells. They are essential for the health and well-being of the nervous system. NGF (nerve growth factor), BDNF (brain-derived neurotrophic factor), NT-3 (neurotrophin-3) and NT-4 (neurotrophin-4) also mediate additional higher-order activities, such as learning, memory and behaviour, in addition to their established functions for cell survival. The effects of neurotrophins depend upon their levels of availability, their affinity of binding to transmembrane receptors and the downstream signalling cascades that are stimulated after receptor activation. Alterations in neurotrophin levels have been implicated in neurodegenerative disorders, such as Alzheimer's disease and Huntington's disease, as well as psychiatric disorders, including depression and substance abuse. Difficulties in administering trophic factors have led to the consideration of using small molecules, such as GPCR (G-protein-coupled receptor) ligands, which can participate in transactivation events. In this review, we consider the signalling pathways activated by neurotrophins in both health and disease states.

scholarly journals Buried ionizable networks are an ancient hallmark of G protein-coupled receptor activation

2015 ◽  
Vol 112 (18) ◽  
pp. 5702-5707 ◽  
Author(s):  
Daniel G. Isom ◽  
Henrik G. Dohlman
Keyword(s):  
G Protein ◽  
Sequence Similarity ◽  
Transmembrane Helix ◽  
Binding Pocket ◽  
Receptor Activation ◽  
Transmembrane Receptors ◽  
Domains Of Life ◽  
G Protein Coupled ◽  
Ionizable Groups

Seven-transmembrane receptors (7TMRs) have evolved in prokaryotes and eukaryotes over hundreds of millions of years. Comparative structural analysis suggests that these receptors may share a remote evolutionary origin, despite their lack of sequence similarity. Here we used structure-based computations to compare 221 7TMRs from all domains of life. Unexpectedly, we discovered that these receptors contain spatially conserved networks of buried ionizable groups. In microbial 7TMRs these networks are used to pump ions across the cell membrane in response to light. In animal 7TMRs, which include light- and ligand-activated G protein-coupled receptors (GPCRs), homologous networks were found to be characteristic of activated receptor conformations. These networks are likely relevant to receptor function because they connect the ligand-binding pocket of the receptor to the nucleotide-binding pocket of the G protein. We propose that agonist and G protein binding facilitate the formation of these electrostatic networks and promote important structural rearrangements such as the displacement of transmembrane helix-6. We anticipate that robust classification of activated GPCR structures will aid the identification of ligands that target activated GPCR structural states.

Hypoxic Pulmonary Vasoconstriction and Chronic Lung Disease

2013 ◽  
Vol 12 (3) ◽  
pp. 135-144 ◽  
Author(s):  
Erik R. Swenson
Keyword(s):  
Pulmonary Hypertension ◽  
Lung Disease ◽  
Hypoxic Pulmonary Vasoconstriction ◽  
World Health ◽  
Disease States ◽  
Pulmonary Vasoconstriction ◽  
Local Ventilation ◽  
Pulmonary Vascular Endothelium ◽  
Health And Disease ◽  
Health Organization

Hypoxic vasoconstriction in the lung is a unique and fundamental characteristic of the pulmonary circulation. It functions in health and disease states to better preserve ventilation-perfusion matching by diverting blood flow to better ventilated regions when local ventilation is compromised. As more areas of lung become hypoxic either with high altitude or global lung disease, then hypoxic pulmonary vasoconstriction (HPV) becomes less effective in ventilation-perfusion matching and can lead to pulmonary hypertension. HPV is intrinsic to the vascular smooth muscle and its mechanisms remain poorly understood. In addition, the pulmonary vascular endothelium, red cells, lung innervation, and numerous circulating vasoactive agents also affect the strength of HPV. This review will discuss the pathophysiology of HPV and address its role in pulmonary hypertension associated with World Health Organization Group 3 diseases. When sustained beyond many hours, HPV may initiate pulmonary vascular remodeling and lead to more fixed and less oxygen-responsive pulmonary hypertension if the hypoxic stimulus is maintained.

In Vitro Immunodetection of Prothymosin Alpha in Normal and Pathological Conditions

2020 ◽  
Vol 27 (29) ◽  
pp. 4840-4854 ◽  
Author(s):  
Chrysoula-Evangelia Karachaliou ◽  
Hubert Kalbacher ◽  
Wolfgang Voelter ◽  
Ourania E. Tsitsilonis ◽  
Evangelia Livaniou
Keyword(s):  
Mammalian Cells ◽  
Therapeutic Potential ◽  
Prothymosin Alpha ◽  
Disease States ◽  
Leading Role ◽  
Tissue Extracts ◽  
Biologic Response ◽  
Health And Disease ◽  
Almost All

Prothymosin alpha (ProTα) is a highly acidic polypeptide, ubiquitously expressed in almost all mammalian cells and tissues and consisting of 109 amino acids in humans. ProTα is known to act both, intracellularly, as an anti-apoptotic and proliferation mediator, and extracellularly, as a biologic response modifier mediating immune responses similar to molecules termed as “alarmins”. Antibodies and immunochemical techniques for ProTα have played a leading role in the investigation of the biological role of ProTα, several aspects of which still remain unknown and contributed to unraveling the diagnostic and therapeutic potential of the polypeptide. This review deals with the so far reported antibodies along with the related immunodetection methodology for ProTα (immunoassays as well as immunohistochemical, immunocytological, immunoblotting, and immunoprecipitation techniques) and its application to biological samples of interest (tissue extracts and sections, cells, cell lysates and cell culture supernatants, body fluids), in health and disease states. In this context, literature information is critically discussed, and some concluding remarks are presented.

Central Histamine, the H3-Receptor and Obesity Therapy

2019 ◽  
Vol 18 (7) ◽  
pp. 516-522
Author(s):  
Néstor F. Díaz ◽  
Héctor Flores-Herrera ◽  
Guadalupe García-López ◽  
Anayansi Molina-Hernández
Keyword(s):  
Body Weight ◽  
Food Intake ◽  
Animal Studies ◽  
Energy Homeostasis ◽  
Receptor Activation ◽  
Receptor Ligands ◽  
Histaminergic System ◽  
H3 Receptor ◽  
Weight One ◽  
The Central Nervous System

The brain histaminergic system plays a pivotal role in energy homeostasis, through H1- receptor activation, it increases the hypothalamic release of histamine that decreases food intake and reduces body weight. One way to increase the release of hypothalamic histamine is through the use of antagonist/inverse agonist for the H3-receptor. Histamine H3-receptors are auto-receptors and heteroreceptors located on the presynaptic membranes and cell soma of neurons, where they negatively regulate the synthesis and release of histamine and other neurotransmitters in the central nervous system. Although several compounds acting as H3-receptor antagonist/inverse agonists have been developed, conflicting results have been reported and only one has been tested as anti-obesity in humans. Animal studies revealed the opposite effect in food intake, energy expeditor, and body weight, depending on the drug, spice, and route of administration, among others. The present review will explore the state of art on the effects of H3-receptor ligands on appetite and body-weight, going through the following: a brief overview of the circuit involved in the control of food intake and energy homeostasis, the participation of the histaminergic system in food intake and body weight, and the H3-receptor as a potential therapeutic target for obesity.

scholarly journals Adhesion GPCRs in Glioblastoma

2021 ◽  
Author(s):  
Gabriele Stephan ◽  
Niklas Ravn-Boess ◽  
Dimitris G Placantonakis
Keyword(s):  
G Protein ◽  
G Protein Coupled Receptors ◽  
The Past ◽  
Novel Treatment ◽  
The Family ◽  
Health And Disease ◽  
Basic Biology ◽  
G Protein Coupled ◽  
Potential Use ◽  
Receptor Family

Abstract Members of the adhesion family of G protein-coupled receptors (GPCRs) have received attention for their roles in health and disease, including cancer. Over the past decade, several members of the family have been implicated in the pathogenesis of glioblastoma. Here, we discuss the basic biology of adhesion GPCRs and review in detail specific members of the receptor family with known functions in glioblastoma. Finally, we discuss the potential use of adhesion GPCRs as novel treatment targets in neuro-oncology.

scholarly journals G Protein-Coupled Estrogen Receptor in Cancer and Stromal Cells: Functions and Novel Therapeutic Perspectives

Cells ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 672
Author(s):  
Richard A. Pepermans ◽  
Geetanjali Sharma ◽  
Eric R. Prossnitz
Keyword(s):  
Estrogen Receptor ◽  
G Protein ◽  
Inflammatory Diseases ◽  
Therapy Resistance ◽  
Breast Cancers ◽  
Obesity And Diabetes ◽  
Therapeutic Value ◽  
Health And Disease ◽  
Multiple Cells ◽  
G Protein Coupled

Estrogen is involved in numerous physiological and pathophysiological systems. Its role in driving estrogen receptor-expressing breast cancers is well established, but it also has important roles in a number of other cancers, acting both on tumor cells directly as well as in the function of multiple cells of the tumor microenvironment, including fibroblasts, immune cells, and adipocytes, which can greatly impact carcinogenesis. One of its receptors, the G protein-coupled estrogen receptor (GPER), has gained much interest over the last decade in both health and disease. Increasing evidence shows that GPER contributes to clinically observed endocrine therapy resistance in breast cancer while also playing a complex role in a number of other cancers. Recent discoveries regarding the targeting of GPER in combination with immune checkpoint inhibition, particularly in melanoma, have led to the initiation of the first Phase I clinical trial for the GPER-selective agonist G-1. Furthermore, its functions in metabolism and corresponding pathophysiological states, such as obesity and diabetes, are becoming more evident and suggest additional therapeutic value in targeting GPER for both cancer and other diseases. Here, we highlight the roles of GPER in several cancers, as well as in metabolism and immune regulation, and discuss the therapeutic value of targeting this estrogen receptor as a potential treatment for cancer as well as contributing metabolic and inflammatory diseases and conditions.

scholarly journals Differential Effects of Toll-Like Receptor Activation and Differential Mediation by MAP Kinases of Immune Responses in Microglial Cells

2021 ◽  
Author(s):  
Jaedeok Kwon ◽  
Christos Arsenis ◽  
Maria Suessmilch ◽  
Alison McColl ◽  
Jonathan Cavanagh ◽  
...  
Keyword(s):  
Map Kinase ◽  
Microglial Activation ◽  
Map Kinases ◽  
Mrna Level ◽  
Cell Types ◽  
Receptor Activation ◽  
Microglial Cells ◽  
Toll Like Receptor ◽  
Disease States ◽  
Nitrite Production

AbstractMicroglial activation is believed to play a role in many psychiatric and neurodegenerative diseases. Based largely on evidence from other cell types, it is widely thought that MAP kinase (ERK, JNK and p38) signalling pathways contribute strongly to microglial activation following immune stimuli acting on toll-like receptor (TLR) 3 or TLR4. We report here that exposure of SimA9 mouse microglial cell line to immune mimetics stimulating TLR4 (lipopolysaccharide—LPS) or TLR7/8 (resiquimod/R848), results in marked MAP kinase activation, followed by induction of nitric oxide synthase, and various cytokines/chemokines. However, in contrast to TLR4 or TLR7/8 stimulation, very few effects of TLR3 stimulation by poly-inosine/cytidine (polyI:C) were detected. Induction of chemokines/cytokines at the mRNA level by LPS and resiquimod were, in general, only marginally affected by MAP kinase inhibition, and expression of TNF, Ccl2 and Ccl5 mRNAs, along with nitrite production, were enhanced by p38 inhibition in a stimulus-specific manner. Selective JNK inhibition enhanced Ccl2 and Ccl5 release. Many distinct responses to stimulation of TLR4 and TLR7 were observed, with JNK mediating TNF protein induction by the latter but not the former, and suppressing Ccl5 release by the former but not the latter. These data reveal complex modulation by MAP kinases of microglial responses to immune challenge, including a dampening of some responses. They demonstrate that abnormal levels of JNK or p38 signalling in microglial cells will perturb their profile of cytokine and chemokine release, potentially contributing to abnormal inflammatory patterns in CNS disease states.

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