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In vivo detection of amyloid-β deposits using heavy chain antibody fragments in a transgenic mouse model for Alzheimer's disease.

Nabuurs RJ, Rutgers KS, Welling MM, Metaxas A, de Backer ME, Rotman M, Bacskai BJ, van Buchem MA, van der Maarel SM, van der Weerd L - PLoS ONE (2012)

Bottom Line: In vivo specificity for Aβ was confirmed for both fluorescently labeled V(H)H, where pa2H remained readily detectable for 24 hours or more after injection.Furthermore, both V(H)H showed affinity for parenchymal and vascular deposits, this in contrast to human tissue, where ni3A specifically targeted only vascular Aβ.Despite a brain uptake that is as yet too low for in vivo imaging, this study provides evidence that V(H)H detect Aβ deposits in vivo, with high selectivity and favorable in vivo characteristics, making them promising tools for further development as diagnostic agents for the distinctive detection of different Aβ deposits.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands. R.J.A.Nabuurs@LUMC.nl

ABSTRACT
This study investigated the in vivo properties of two heavy chain antibody fragments (V(H)H), ni3A and pa2H, to differentially detect vascular or parenchymal amyloid-β deposits characteristic for Alzheimer's disease and cerebral amyloid angiopathy. Blood clearance and biodistribution including brain uptake were assessed by bolus injection of radiolabeled V(H)H in APP/PS1 mice or wildtype littermates. In addition, in vivo specificity for Aβ was examined in more detail with fluorescently labeled V(H)H by circumventing the blood-brain barrier via direct application or intracarotid co-injection with mannitol. All V(H)H showed rapid renal clearance (10-20 min). Twenty-four hours post-injection (99m)Tc-pa2H resulted in a small yet significant higher cerebral uptake in the APP/PS1 animals. No difference in brain uptake were observed for (99m)Tc-ni3A or DTPA((111)In)-pa2H, which lacked additional peptide tags to investigate further clinical applicability. In vivo specificity for Aβ was confirmed for both fluorescently labeled V(H)H, where pa2H remained readily detectable for 24 hours or more after injection. Furthermore, both V(H)H showed affinity for parenchymal and vascular deposits, this in contrast to human tissue, where ni3A specifically targeted only vascular Aβ. Despite a brain uptake that is as yet too low for in vivo imaging, this study provides evidence that V(H)H detect Aβ deposits in vivo, with high selectivity and favorable in vivo characteristics, making them promising tools for further development as diagnostic agents for the distinctive detection of different Aβ deposits.

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Related in: MedlinePlus

Immunofluorescence with VHH-Alexa594.Shown are the results of immunofluorescence staining with ni3A- and pa2H-Alexa594 on cryosections of APP/PS1 murine and human AD/CAA brain tissue, including wildtype or healthy controls. Both VHH stain positive for CAA in all sections (A, D, G, J). Only ni3A-Alexa594 stained negative for human parenchymal Aβ (B), while pa2H stained positive for several types of parenchymal Aβ deposits (G, H, J, K) in both humans and mice. In either human of murine control tissue no such staining patterns were observed.(C, F, I, L)
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pone-0038284-g005: Immunofluorescence with VHH-Alexa594.Shown are the results of immunofluorescence staining with ni3A- and pa2H-Alexa594 on cryosections of APP/PS1 murine and human AD/CAA brain tissue, including wildtype or healthy controls. Both VHH stain positive for CAA in all sections (A, D, G, J). Only ni3A-Alexa594 stained negative for human parenchymal Aβ (B), while pa2H stained positive for several types of parenchymal Aβ deposits (G, H, J, K) in both humans and mice. In either human of murine control tissue no such staining patterns were observed.(C, F, I, L)

Mentions: Selectivity for specific Aβ deposits was not altered after fluorescent labeling of the VHH, since on human sections, ni3A-Alexa594 selectively stained vascular Aβ (Figure 5 A–C), and pa2H-Alexa594 stained both parenchymal and vascular Aβ.(Figure 5 G–I) On murine material all Aβ deposits were stained by both fluorescent VHH.(Figure 5 D–F & J–L)


In vivo detection of amyloid-β deposits using heavy chain antibody fragments in a transgenic mouse model for Alzheimer's disease.

Nabuurs RJ, Rutgers KS, Welling MM, Metaxas A, de Backer ME, Rotman M, Bacskai BJ, van Buchem MA, van der Maarel SM, van der Weerd L - PLoS ONE (2012)

Immunofluorescence with VHH-Alexa594.Shown are the results of immunofluorescence staining with ni3A- and pa2H-Alexa594 on cryosections of APP/PS1 murine and human AD/CAA brain tissue, including wildtype or healthy controls. Both VHH stain positive for CAA in all sections (A, D, G, J). Only ni3A-Alexa594 stained negative for human parenchymal Aβ (B), while pa2H stained positive for several types of parenchymal Aβ deposits (G, H, J, K) in both humans and mice. In either human of murine control tissue no such staining patterns were observed.(C, F, I, L)
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3366949&req=5

pone-0038284-g005: Immunofluorescence with VHH-Alexa594.Shown are the results of immunofluorescence staining with ni3A- and pa2H-Alexa594 on cryosections of APP/PS1 murine and human AD/CAA brain tissue, including wildtype or healthy controls. Both VHH stain positive for CAA in all sections (A, D, G, J). Only ni3A-Alexa594 stained negative for human parenchymal Aβ (B), while pa2H stained positive for several types of parenchymal Aβ deposits (G, H, J, K) in both humans and mice. In either human of murine control tissue no such staining patterns were observed.(C, F, I, L)
Mentions: Selectivity for specific Aβ deposits was not altered after fluorescent labeling of the VHH, since on human sections, ni3A-Alexa594 selectively stained vascular Aβ (Figure 5 A–C), and pa2H-Alexa594 stained both parenchymal and vascular Aβ.(Figure 5 G–I) On murine material all Aβ deposits were stained by both fluorescent VHH.(Figure 5 D–F & J–L)

Bottom Line: In vivo specificity for Aβ was confirmed for both fluorescently labeled V(H)H, where pa2H remained readily detectable for 24 hours or more after injection.Furthermore, both V(H)H showed affinity for parenchymal and vascular deposits, this in contrast to human tissue, where ni3A specifically targeted only vascular Aβ.Despite a brain uptake that is as yet too low for in vivo imaging, this study provides evidence that V(H)H detect Aβ deposits in vivo, with high selectivity and favorable in vivo characteristics, making them promising tools for further development as diagnostic agents for the distinctive detection of different Aβ deposits.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands. R.J.A.Nabuurs@LUMC.nl

ABSTRACT
This study investigated the in vivo properties of two heavy chain antibody fragments (V(H)H), ni3A and pa2H, to differentially detect vascular or parenchymal amyloid-β deposits characteristic for Alzheimer's disease and cerebral amyloid angiopathy. Blood clearance and biodistribution including brain uptake were assessed by bolus injection of radiolabeled V(H)H in APP/PS1 mice or wildtype littermates. In addition, in vivo specificity for Aβ was examined in more detail with fluorescently labeled V(H)H by circumventing the blood-brain barrier via direct application or intracarotid co-injection with mannitol. All V(H)H showed rapid renal clearance (10-20 min). Twenty-four hours post-injection (99m)Tc-pa2H resulted in a small yet significant higher cerebral uptake in the APP/PS1 animals. No difference in brain uptake were observed for (99m)Tc-ni3A or DTPA((111)In)-pa2H, which lacked additional peptide tags to investigate further clinical applicability. In vivo specificity for Aβ was confirmed for both fluorescently labeled V(H)H, where pa2H remained readily detectable for 24 hours or more after injection. Furthermore, both V(H)H showed affinity for parenchymal and vascular deposits, this in contrast to human tissue, where ni3A specifically targeted only vascular Aβ. Despite a brain uptake that is as yet too low for in vivo imaging, this study provides evidence that V(H)H detect Aβ deposits in vivo, with high selectivity and favorable in vivo characteristics, making them promising tools for further development as diagnostic agents for the distinctive detection of different Aβ deposits.

Show MeSH
Related in: MedlinePlus