Title:Evaluation and Characterization of Modified K114 Method to Localize
Plaques in Rodent and Plaques and Tangles in Human Brain Tissue
Volume: 21
Issue: 1
Author(s): Sanjana Padala, Sharay Setti, James Raymick, Joseph Hanig and Sumit Sarkar*
Affiliation:
- Division of Neurotoxicology, National Center for Toxicological Research, U.S. Food & Drug Administration, Jefferson,
AR72079, USA
Keywords:
Amyloid beta, plaques, neurofibrillary tangles, histochemical tracer, styrylbenzene, Alzheimer’s disease, phosphorylated tau.
Abstract:
Background: A plethora of studies has shown the utility of several chemical dyes due
to their affinity to bind Aβ to enable visualization of plaques under light or fluorescence microscope,
and some of them showed affinity to bind neurofibrillary tangles (NFT) as well. However,
only a few of them have the propensity to bind both senile plaques (SP) and NFT simultaneously.
Objective: In our current study, we aimed to modify the K114 dye and the staining procedure to
substantially improve the staining of amyloid plaques in both human and rodent brains and neurofibrillary
tangles in the human brain.
Methods: We modified the K114 solution and the staining procedure using Sudan Black as a modifier.
Additionally, to evaluate the target of the modified K114, we performed double labeling of
K114 and increased Aβ against three different epitopes. We used 5 different antibodies to detect
phosphorylated tau to understand the specific targets that modified K114 binds.
Results: Dual labeling using hyperphosphorylated antibodies against AT8, pTau, and TNT1 revealed
that more than 80% hyperphosphorylated tau colocalized with tangles that were positive
for modified K114, whereas more than 70% of the hyperphosphorylated tau colocalized with modified
K114. On the other hand, more than 80% of the plaques that were stained with Aβ MOAB-2
were colocalized with modified K114.
Conclusion: Our modified method can label amyloid plaques within 5 min in the rat brain and
within 20 min in the human brain. Our results indicated that modified K114 could be used as a
valuable tool for detecting amyloid plaques and tangles with high contrast and resolution relative
to other conventional fluorescence markers.
