Labeling of Cerebral Amyloid {beta} Deposits In Vivo Using Intranasal Basic Fibroblast Growth Factor and Serum Amyloid P Component in Mice

Labeling of Cerebral Amyloid ß Deposits In Vivo Using Intranasal Basic Fibroblast Growth Factor and Serum Amyloid P Component in Mice

Jiong Shi, MD, PhD¹, George Perry, PhD², Marc S. Berridge, PhD³, Gjumrakch Aliev, MD, PhD⁴, Sandy L. Siedlak, BS², Mark A. Smith, PhD², Joseph C. LaManna, PhD¹ and Robert P. Friedland, MD¹

¹ Department of Neurology, Case Western Reserve University, University Hospitals of Cleveland, Cleveland, Ohio
² Department of Pathology, Case Western Reserve University, University Hospitals of Cleveland, Cleveland, Ohio
³ Department of Radiology, Case Western Reserve University, University Hospitals of Cleveland, Cleveland, Ohio
⁴ Department of Anatomy, Case Western Reserve University, University Hospitals of Cleveland, Cleveland, Ohio

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FIGURE 1. Biodistribution of ¹²⁵I-bFGF in 2 groups of experimental animals, Tg(+) and control, given intranasal injection of ¹²⁵I-bFGF (33.3 MBq/µL per 10 g of body weight). (A) Brain distribution of ¹²⁵I-bFGF is depicted as mean ± SD (n = 5 in each group). *P < 0.05 vs. control. (B) Whole-body distribution of ¹²⁵I-bFGF is depicted as mean ± SEM (n = 5 in each group). When SEM is not depicted, it was too small to be shown.

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FIGURE 2. Adjacent serial sections indicate that immunostaining with antisera to AßPP shows localization of amyloid plaques (A) and that intranasally injected SAP binds to amyloid plaques in Tg mouse cortex as detected by antibody to SAP (B). (D) Brain sections from Tg mice receiving bovine serum albumin plus vehicle immunostained for SAP show no reaction in amyloid plaques, although many plaques are seen on adjacent serial sections stained for AßPP (C). Scale bar = 50 µm. Arrows mark same plaques in serial sections (A and B) and (C and D).

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FIGURE 3. Light microscopic study of bFGF localization in AßPP Tg mouse cortex, with and without intranasal bFGF injection. bFGF is not readily detectable in neurons in Tg(-) mice after receiving bFGF intranasally (A) or in Tg(+) mice without bFGF injection (B). (C) Nasally injected bFGF bound to cytoplasm of neurons around Aß deposits in frontal, parietal, and occipital regions in Tg(+) mice. Scale bar = 50 µm.

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FIGURE 4. Electron microscopy immunogold staining in neuritic plaques in Tg(+) mouse cortex. (A) Tg(+) mice with intravenous injection of bFGF do not show presence of bFGF in brain (original magnification, x8,000). (B) Same area as in A under higher magnification (x20,000). (C) Representative electron micrograph shows that peripheral margins of neuritic plaques from animals that received bFGF intranasally contain bFGF immunogold reactivity (original magnification, x50,000). (D) bFGF is also associated with amyloid fibrils in plaque after intranasal injection (original magnification, x50,000). Arrows indicate bFGF gold labeling. Scale bars = 10 nm.