PURPOSE: In this study, we evaluated the 12-O-tetradecanoyl-phorbol-13-acetate (TPA)-induced acute and chronic inflammation in living mice by PET imaging of TNF-alpha and integrin alpha(v)beta(3) expression. METHODS: TPA was topically applied to the right ear of BALB/c mice every other day to create the inflammation model. (64)Cu-DOTA-etanercept and (64)Cu-DOTA-E{E[c(RGDyK)](2)}(2) were used for PET imaging of TNF-alpha and integrin alpha(v)beta(3) expression in both acute and chronic inflammation. Hematoxylin and eosin staining, ex vivo autoradiography, direct tissue sampling, and immunofluorescence staining were also performed to confirm the non-invasive PET imaging results. RESULTS: The ear thickness increased significantly and the TNF-alpha level more than tripled after a single TPA challenge. MicroPET imaging using (64)Cu-DOTA-etanercept revealed high activity accumulation in the inflamed ear, reaching 11.1 +/- 1.3, 13.0 +/- 2.0, 10.9 +/- 1.4, 10.2 +/- 2.2%ID/g at 1, 4, 16, and 24 h post injection, respectively (n = 3). Repeated TPA challenges caused TPA-specific chronic inflammation and reduced (64)Cu-DOTA-etanercept uptake due to lowered TNF-alpha expression. (64)Cu-DOTA-E{E[c(RGDyK)](2)}(2) uptake in the chronically inflamed ears (after four and eight TPA challenges) was significantly higher than in the control ears and those after one TPA challenge. Immunofluorescence staining revealed increased integrin beta(3) expression, consistent with the non-invasive PET imaging results using (64)Cu-DOTA-E{E[c(RGDyK)](2)}(2) as an integrin alpha(v)beta(3)-specific radiotracer. Biodistribution and autoradiography studies further confirmed the quantification capability of microPET imaging. CONCLUSION: Successful PET imaging of TNF-alpha expression in acute inflammation and integrin alpha(v)beta(3) expression in chronic inflammation provides the rationale for multiple target evaluation over time to fully understand the inflammation processes.
PURPOSE: In this study, we evaluated the 12-O-tetradecanoyl-phorbol-13-acetate (TPA)-induced acute and chronic inflammation in living mice by PET imaging of TNF-alpha and integrin alpha(v)beta(3) expression. METHODS:TPA was topically applied to the right ear of BALB/c mice every other day to create the inflammation model. (64)Cu-DOTA-etanercept and (64)Cu-DOTA-E{E[c(RGDyK)](2)}(2) were used for PET imaging of TNF-alpha and integrin alpha(v)beta(3) expression in both acute and chronic inflammation. Hematoxylin and eosin staining, ex vivo autoradiography, direct tissue sampling, and immunofluorescence staining were also performed to confirm the non-invasive PET imaging results. RESULTS: The ear thickness increased significantly and the TNF-alpha level more than tripled after a single TPA challenge. MicroPET imaging using (64)Cu-DOTA-etanercept revealed high activity accumulation in the inflamed ear, reaching 11.1 +/- 1.3, 13.0 +/- 2.0, 10.9 +/- 1.4, 10.2 +/- 2.2%ID/g at 1, 4, 16, and 24 h post injection, respectively (n = 3). Repeated TPA challenges caused TPA-specific chronic inflammation and reduced (64)Cu-DOTA-etanercept uptake due to lowered TNF-alpha expression. (64)Cu-DOTA-E{E[c(RGDyK)](2)}(2) uptake in the chronically inflamed ears (after four and eight TPA challenges) was significantly higher than in the control ears and those after one TPA challenge. Immunofluorescence staining revealed increased integrin beta(3) expression, consistent with the non-invasive PET imaging results using (64)Cu-DOTA-E{E[c(RGDyK)](2)}(2) as an integrin alpha(v)beta(3)-specific radiotracer. Biodistribution and autoradiography studies further confirmed the quantification capability of microPET imaging. CONCLUSION: Successful PET imaging of TNF-alpha expression in acute inflammation and integrin alpha(v)beta(3) expression in chronic inflammation provides the rationale for multiple target evaluation over time to fully understand the inflammation processes.
Authors: Ioannis E Koutroubakis; Georgia Tsiolakidou; Konstantinos Karmiris; Elias A Kouroumalis Journal: Inflamm Bowel Dis Date: 2006-06 Impact factor: 5.325
Authors: Y Waerzeggers; P Monfared; T Viel; A Faust; K Kopka; M Schäfers; B Tavitian; A Winkeler; A Jacobs Journal: Br J Radiol Date: 2011-12 Impact factor: 3.039
Authors: Zhonglin Liu; Leonie Wyffels; Christy Barber; Li Wan; Hua Xu; Mizhou M Hui; Lars R Furenlid; James M Woolfenden Journal: Nucl Med Biol Date: 2012-06-28 Impact factor: 2.408
Authors: Riikka Siitonen; Emilia Peuhu; Anu Autio; Heidi Liljenbäck; Elina Mattila; Olli Metsälä; Meeri Käkelä; Tiina Saanijoki; Ingrid Dijkgraaf; Sirpa Jalkanen; Johanna Ivaska; Anne Roivainen Journal: J Nucl Med Date: 2019-03-08 Impact factor: 10.057
Authors: Thomas Ebenhan; Janke Kleynhans; Jan Rijn Zeevaart; Jae Min Jeong; Mike Sathekge Journal: Eur J Nucl Med Mol Imaging Date: 2020-09-12 Impact factor: 9.236