1
|
Wang J, Beecher K. TSPO: an emerging role in appetite for a therapeutically promising biomarker. Open Biol 2021; 11:210173. [PMID: 34343461 PMCID: PMC8331234 DOI: 10.1098/rsob.210173] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
There is accumulating evidence that an obesogenic Western diet causes neuroinflammatory damage to the brain, which then promotes further appetitive behaviour. Neuroinflammation has been extensively studied by analysing the translocator protein of 18 kDa (TSPO), a protein that is upregulated in the inflamed brain following a damaging stimulus. As a result, there is a rich supply of TSPO-specific agonists, antagonists and positron emission tomography ligands. One TSPO ligand, etifoxine, is also currently used clinically for the treatment of anxiety with a minimal side-effect profile. Despite the neuroinflammatory pathogenesis of diet-induced obesity, and the translational potential of targeting TSPO, there is sparse literature characterizing the effect of TSPO on appetite. Therefore, in this review, the influence of TSPO on appetite is discussed. Three putative mechanisms for TSPO's appetite-modulatory effect are then characterized: the TSPO–allopregnanolone–GABAAR signalling axis, glucosensing in tanycytes and association with the synaptic protein RIM-BP1. We highlight that, in addition to its plethora of functions, TSPO is a regulator of appetite. This review ultimately suggests that the appetite-modulating function of TSPO should be further explored due to its potential therapeutic promise.
Collapse
Affiliation(s)
- Joshua Wang
- Addiction Neuroscience and Obesity Laboratory, School of Clinical Sciences, Faculty of Health, Translational Research Institute, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Kate Beecher
- Addiction Neuroscience and Obesity Laboratory, School of Clinical Sciences, Faculty of Health, Translational Research Institute, Queensland University of Technology, Brisbane, Queensland, Australia
| |
Collapse
|
2
|
Marginedas-Freixa I, Alvarez CL, Moras M, Hattab C, Bouyer G, Chene A, Lefevre SD, Le Van Kim C, Bihel F, Schwarzbaum PJ, Ostuni MA. Induction of ATP Release, PPIX Transport, and Cholesterol Uptake by Human Red Blood Cells Using a New Family of TSPO Ligands. Int J Mol Sci 2018; 19:ijms19103098. [PMID: 30308949 PMCID: PMC6213633 DOI: 10.3390/ijms19103098] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 10/05/2018] [Accepted: 10/07/2018] [Indexed: 02/07/2023] Open
Abstract
Two main isoforms of the Translocator Protein (TSPO) have been identified. TSPO1 is ubiquitous and is mainly present at the outer mitochondrial membrane of most eukaryotic cells, whereas, TSPO2 is specific to the erythroid lineage, located at the plasma membrane, the nucleus, and the endoplasmic reticulum. The design of specific tools is necessary to determine the molecular associations and functions of TSPO, which remain controversial nowadays. We recently demonstrated that TSPO2 is involved in a supramolecular complex of the erythrocyte membrane, where micromolar doses of the classical TSPO ligands induce ATP release and zinc protoporphyrin (ZnPPIX) transport. In this work, three newly-designed ligands (NCS1016, NCS1018, and NCS1026) were assessed for their ability to modulate the functions of various erythrocyte's and compare them to the TSPO classical ligands. The three new ligands were effective in reducing intraerythrocytic Plasmodium growth, without compromising erythrocyte survival. While NCS1016 and NCS1018 were the most effective ligands in delaying sorbitol-induced hemolysis, NCS1016 induced the highest uptake of ZnPPIX and NCS1026 was the only ligand inhibiting the cholesterol uptake. Differential effects of ligands are probably due, not only, to ligand features, but also to the dynamic interaction of TSPO with various partners at the cell membrane. Further studies are necessary to fully understand the mechanisms of the TSPO's complex activation.
Collapse
Affiliation(s)
- Irene Marginedas-Freixa
- UMR-S1134, Integrated Biology of Red Blood Cells, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Université de la Réunion, Université des Antilles, F-75015 Paris, France.
- Institut National de la Transfusion Sanguine, Laboratoire d'Excellence GR-Ex, F-75015 Paris, France.
| | - Cora L Alvarez
- Instituto de Química y Fisico-Química Biológicas "Prof. Alejandro C. Paladini", UBA, CONICET, Facultad de Farmacia y Bioquímica, Junín 956, C1113AAD Buenos Aires, Argentina.
- Departamento de Biodiversidad y Biología Experimental, Facultad Ciencias Exactas y Naturales, Universidad de Buenos Aires, C1113AAD Buenos Aires, Argentina.
| | - Martina Moras
- UMR-S1134, Integrated Biology of Red Blood Cells, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Université de la Réunion, Université des Antilles, F-75015 Paris, France.
- Institut National de la Transfusion Sanguine, Laboratoire d'Excellence GR-Ex, F-75015 Paris, France.
| | - Claude Hattab
- UMR-S1134, Integrated Biology of Red Blood Cells, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Université de la Réunion, Université des Antilles, F-75015 Paris, France.
- Institut National de la Transfusion Sanguine, Laboratoire d'Excellence GR-Ex, F-75015 Paris, France.
| | - Guillaume Bouyer
- UMR 8227 LBI2M, Comparative Erythrocyte's Physiology, CNRS, Sorbonne Université, Laboratoire d'Excellence GR-Ex, F-29680 Roscoff, France.
| | - Arnaud Chene
- UMR-S1134, Integrated Biology of Red Blood Cells, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Université de la Réunion, Université des Antilles, F-75015 Paris, France.
- Institut National de la Transfusion Sanguine, Laboratoire d'Excellence GR-Ex, F-75015 Paris, France.
| | - Sophie D Lefevre
- UMR-S1134, Integrated Biology of Red Blood Cells, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Université de la Réunion, Université des Antilles, F-75015 Paris, France.
- Institut National de la Transfusion Sanguine, Laboratoire d'Excellence GR-Ex, F-75015 Paris, France.
| | - Caroline Le Van Kim
- UMR-S1134, Integrated Biology of Red Blood Cells, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Université de la Réunion, Université des Antilles, F-75015 Paris, France.
- Institut National de la Transfusion Sanguine, Laboratoire d'Excellence GR-Ex, F-75015 Paris, France.
| | - Frederic Bihel
- UMR7200, Laboratoire d'Innovation Thérapeutique, Faculty of Pharmacy, University of Strasbourg, CNRS, F-67400 Illkirch Graffenstaden, France.
| | - Pablo J Schwarzbaum
- Instituto de Química y Fisico-Química Biológicas "Prof. Alejandro C. Paladini", UBA, CONICET, Facultad de Farmacia y Bioquímica, Junín 956, C1113AAD Buenos Aires, Argentina.
- Departamento de Química Biológica, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, C1113AAD Buenos Aires, Argentina.
| | - Mariano A Ostuni
- UMR-S1134, Integrated Biology of Red Blood Cells, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Université de la Réunion, Université des Antilles, F-75015 Paris, France.
- Institut National de la Transfusion Sanguine, Laboratoire d'Excellence GR-Ex, F-75015 Paris, France.
| |
Collapse
|
3
|
Bhoola NH, Mbita Z, Hull R, Dlamini Z. Translocator Protein (TSPO) as a Potential Biomarker in Human Cancers. Int J Mol Sci 2018; 19:ijms19082176. [PMID: 30044440 PMCID: PMC6121633 DOI: 10.3390/ijms19082176] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 06/21/2018] [Accepted: 06/24/2018] [Indexed: 11/17/2022] Open
Abstract
TSPO is a receptor involved in the regulation of cellular proliferation, apoptosis and mitochondrial functions. Previous studies showed that the expression of TSPO protein correlated positively with tumour malignancy and negatively with patient survival. The aim of this study was to determine the transcription of Tspo mRNA in various types of normal and cancer tissues. In situ hybridization was performed to localise the Tspo mRNA in various human normal and cancer tissues. The relative level of Tspo mRNA was quantified using fluorescent intensity and visual estimation of colorimetric staining. RT-PCR was used to confirm these mRNA levels in normal lung, lung cancer, liver cancer, and cervical cancer cell lines. There was a significant increase in the level of transcription in liver, prostate, kidney, and brain cancers while a significant decrease was observed in cancers of the colon and lung. Quantitative RT-PCR confirmed that the mRNA levels of Tspo are higher in a normal lung cell line than in a lung cancer cell line. An increase in the expression levels of Tspo mRNA is not necessarily a good diagnostic biomarker in most cancers with changes not being large enough to be significantly different when detected by in situ hybridisation.
Collapse
Affiliation(s)
- Nimisha H Bhoola
- Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2193, South Africa.
| | - Zukile Mbita
- Department of Biochemistry, Microbiology and Biotechnology, University of Limpopo, Private Bag X1106, Sovenga 0727, South Africa.
| | - Rodney Hull
- Research, Innovation & Engagements Portfolio, Mangosuthu University of Technology, Durban 4031, South Africa.
| | - Zodwa Dlamini
- Research, Innovation & Engagements Portfolio, Mangosuthu University of Technology, Durban 4031, South Africa.
| |
Collapse
|