UNLABELLED: PET of gene expression in the brain may greatly facilitate neuroscience research and potential clinical implementation of gene or cell therapy of central nervous system diseases. To date, no adequate PET reporter system is available for the central nervous system because available tracers either do not cross the intact blood-brain barrier or have high background signals. Here we report the first, to our knowledge, PET reporter system for imaging gene expression in the intact brain. METHODS: We selected the human type 2 cannabinoid receptor (hCB(2)) as a reporter because of its low basal expression in the brain. An inactive mutant (D80N) was chosen so as not to interfere with signal transduction. As a reporter probe we used the (11)C-labeled CB(2) ligand, (11)C-GW405833, which readily crosses the blood-brain barrier. Dual-modality imaging lentiviral and adeno-associated viral vectors encoding both hCB(2)(D80N) and firefly luciferase or enhanced green fluorescent protein were engineered and validated in cell culture. Next, hCB(2)(D80N) was locoregionally overexpressed in rat striatum by stereotactic injection of lentiviral and adeno-associated viral vectors. RESULTS: Kinetic PET revealed specific and reversible CB(2) binding of (11)C-GW405833 in the transduced rat striatum. hCB(2) and firefly luciferase expression was followed until 9 mo and showed similar kinetics. Both hCB(2) expression and enhanced green fluorescent protein expression were confirmed by immunohistochemistry. CONCLUSION: Dual-modality imaging viral vectors encoding hCB(2)(D80N) were engineered, and the reporter system was validated in different animal species. The results support the potential future clinical use of CB(2) as a PET reporter in the intact brain.
UNLABELLED: PET of gene expression in the brain may greatly facilitate neuroscience research and potential clinical implementation of gene or cell therapy of central nervous system diseases. To date, no adequate PET reporter system is available for the central nervous system because available tracers either do not cross the intact blood-brain barrier or have high background signals. Here we report the first, to our knowledge, PET reporter system for imaging gene expression in the intact brain. METHODS: We selected the human type 2 cannabinoid receptor (hCB(2)) as a reporter because of its low basal expression in the brain. An inactive mutant (D80N) was chosen so as not to interfere with signal transduction. As a reporter probe we used the (11)C-labeled CB(2) ligand, (11)C-GW405833, which readily crosses the blood-brain barrier. Dual-modality imaging lentiviral and adeno-associated viral vectors encoding both hCB(2)(D80N) and firefly luciferase or enhanced green fluorescent protein were engineered and validated in cell culture. Next, hCB(2)(D80N) was locoregionally overexpressed in rat striatum by stereotactic injection of lentiviral and adeno-associated viral vectors. RESULTS: Kinetic PET revealed specific and reversible CB(2) binding of (11)C-GW405833 in the transduced rat striatum. hCB(2) and firefly luciferase expression was followed until 9 mo and showed similar kinetics. Both hCB(2) expression and enhanced green fluorescent protein expression were confirmed by immunohistochemistry. CONCLUSION: Dual-modality imaging viral vectors encoding hCB(2)(D80N) were engineered, and the reporter system was validated in different animal species. The results support the potential future clinical use of CB(2) as a PET reporter in the intact brain.
Authors: Kristina Herfert; Julia G Mannheim; Laura Kuebler; Sabina Marciano; Mario Amend; Christoph Parl; Hanna Napieczynska; Florian M Maier; Salvador Castaneda Vega; Bernd J Pichler Journal: Mol Imaging Biol Date: 2020-04 Impact factor: 3.488
Authors: Tom Haywood; Corinne Beinat; Gayatri Gowrishankar; Chirag B Patel; Israt S Alam; Surya Murty; Sanjiv Sam Gambhir Journal: Proc Natl Acad Sci U S A Date: 2019-05-23 Impact factor: 11.205
Authors: Alena V Savonenko; Tatiana Melnikova; Yuchuan Wang; Hayden Ravert; Yongjun Gao; Jeremy Koppel; Deidre Lee; Olga Pletnikova; Eugenia Cho; Nuzhat Sayyida; Andrew Hiatt; Juan Troncoso; Peter Davies; Robert F Dannals; Martin G Pomper; Andrew G Horti Journal: PLoS One Date: 2015-06-18 Impact factor: 3.240
Authors: Linjing Mu; Roger Slavik; Adrienne Müller; Kasim Popaj; Stjepko Cermak; Markus Weber; Roger Schibli; Stefanie D Krämer; Simon M Ametamey Journal: Pharmaceuticals (Basel) Date: 2014-03-06