TY - JOUR
T1 - Characteristics of TBS-extractable hyperphosphorylated tau species
T2 - Aggregation intermediates in rTg4510 mouse brain
AU - Sahara, Naruhiko
AU - De Ture, Michael
AU - Ren, Yan
AU - Ebrahim, Abdul Shukkur
AU - Kang, Dongcheul
AU - Knight, Joshua
AU - Volbracht, Christiane
AU - Pedersen, Jan Torleif
AU - Dickson, Dennis W.
AU - Yen, Shu Hui
AU - Lewis, Jada
PY - 2013
Y1 - 2013
N2 - Conditional overexpression of four-repeat human tau containing the P301L missense mutation in the rTg4510 mouse model of tauopathy leads to progressive accumulation of neurofibrillary tangles and hyperphosphorylated, sarkosyl-insoluble tau species, which are biochemically comparable to abnormal tau characteristic of hereditary tauopathies termed FTDP-17. To fully understand the impact of tau species at different stages of self-assembly on neurodegeneration, we fractionated rTg4510 brain representing several stages of tauopathy to obtain TBS-extractable (S1), high salt/sarkosyl-extractable (S3), and sarkosyl-insoluble (P3) fractions. Under reducing condition, the S1 fraction was demonstrated by western blotting to contain both 50-60 kDa normally-sized and 64 kDa tau. Both are thermo-stable, but the 64 kDa tau showed a higher degree of phosphorylation. Under non-reducing condition, nearly all TBS-extractable 64 kDa tau were detected as ∼130 kDa species consistent with the size of dimer. Quantitative analysis showed ∼80 times more 64 kDa tau in S1 than P3 fraction. Immunoelectron microscopy revealed tau-positive granules/short filaments in S1 fraction. These structures displayed MC1 immunoreactivities indicative of conformational/pathological change of tau. MC1 immunoreactivity was detected by dot blotting in samples from 2.5 month-old mice, whereas Ab39 immunoreactivity indicative of late stages of tau assembly was detected only in P3 fraction. Quantitative analysis also demonstrated a significant inverse correlation between brain weight and 64 kDa tau, but the level of TBS-extractable 64 kDa tau reflects neurodegeneration better than that of sarkosyl-insoluble 64 kDa tau. Together, the findings suggest that TBS-extractable 64 kDa tau production is a potential target for therapeutic intervention of tauopathies.
AB - Conditional overexpression of four-repeat human tau containing the P301L missense mutation in the rTg4510 mouse model of tauopathy leads to progressive accumulation of neurofibrillary tangles and hyperphosphorylated, sarkosyl-insoluble tau species, which are biochemically comparable to abnormal tau characteristic of hereditary tauopathies termed FTDP-17. To fully understand the impact of tau species at different stages of self-assembly on neurodegeneration, we fractionated rTg4510 brain representing several stages of tauopathy to obtain TBS-extractable (S1), high salt/sarkosyl-extractable (S3), and sarkosyl-insoluble (P3) fractions. Under reducing condition, the S1 fraction was demonstrated by western blotting to contain both 50-60 kDa normally-sized and 64 kDa tau. Both are thermo-stable, but the 64 kDa tau showed a higher degree of phosphorylation. Under non-reducing condition, nearly all TBS-extractable 64 kDa tau were detected as ∼130 kDa species consistent with the size of dimer. Quantitative analysis showed ∼80 times more 64 kDa tau in S1 than P3 fraction. Immunoelectron microscopy revealed tau-positive granules/short filaments in S1 fraction. These structures displayed MC1 immunoreactivities indicative of conformational/pathological change of tau. MC1 immunoreactivity was detected by dot blotting in samples from 2.5 month-old mice, whereas Ab39 immunoreactivity indicative of late stages of tau assembly was detected only in P3 fraction. Quantitative analysis also demonstrated a significant inverse correlation between brain weight and 64 kDa tau, but the level of TBS-extractable 64 kDa tau reflects neurodegeneration better than that of sarkosyl-insoluble 64 kDa tau. Together, the findings suggest that TBS-extractable 64 kDa tau production is a potential target for therapeutic intervention of tauopathies.
KW - Dimer
KW - FTDP-17
KW - hyperphosphorylation
KW - tau protein
KW - tauopathy
KW - transgenic mice
UR - http://www.scopus.com/inward/record.url?scp=84872441246&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84872441246&partnerID=8YFLogxK
U2 - 10.3233/JAD-2012-121093
DO - 10.3233/JAD-2012-121093
M3 - Article
C2 - 22941973
AN - SCOPUS:84872441246
SN - 1387-2877
VL - 33
SP - 249
EP - 263
JO - Journal of Alzheimer's Disease
JF - Journal of Alzheimer's Disease
IS - 1
ER -