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Reducing tau aggregates with anle138b delays disease progression in a mouse model of tauopathies.

Wagner J, Krauss S, Shi S, Ryazanov S, Steffen J, Miklitz C, Leonov A, Kleinknecht A, Göricke B, Weishaupt JH, Weckbecker D, Reiner AM, Zinth W, Levin J, Ehninger D, Remy S, Kretzschmar HA, Griesinger C, Giese A, Fuhrmann M - Acta Neuropathol. (2015)

Bottom Line: Here, we show that the di-phenyl-pyrazole anle138b binds to aggregated tau and inhibits tau aggregation in vitro and in vivo.In addition, we found decreased synapse and neuron loss accompanied by a decreased gliosis in the hippocampus.Our results suggest that reducing tau aggregates with anle138b may represent an effective and promising approach for the treatment of human tauopathies.

View Article: PubMed Central - PubMed

Affiliation: German Center for Neurodegenerative Diseases (DZNE), Ludwig-Erhard-Allee 2, 53175, Bonn, Germany.

ABSTRACT
Pathological tau aggregation leads to filamentous tau inclusions and characterizes neurodegenerative tauopathies such as Alzheimer's disease and frontotemporal dementia and parkinsonism linked to chromosome 17. Tau aggregation coincides with clinical symptoms and is thought to mediate neurodegeneration. Transgenic mice overexpressing mutant human P301S tau exhibit many neuropathological features of human tauopathies including behavioral deficits and increased mortality. Here, we show that the di-phenyl-pyrazole anle138b binds to aggregated tau and inhibits tau aggregation in vitro and in vivo. Furthermore, anle138b treatment effectively ameliorates disease symptoms, increases survival time and improves cognition of tau transgenic PS19 mice. In addition, we found decreased synapse and neuron loss accompanied by a decreased gliosis in the hippocampus. Our results suggest that reducing tau aggregates with anle138b may represent an effective and promising approach for the treatment of human tauopathies.

No MeSH data available.


Related in: MedlinePlus

Anle138b reduces insoluble tau levels in PS19 mice a Immunoblots of brain homogenates of non-transgenic (ntg), untreated and anle138b-treated PS19 mice probed with HT7 and E178 antibody detecting total tau. b Densitometric analysis of immunoblots showing the brain protein levels of total tau (HT7 and E178) in untreated and anle138b-treated PS19 mice. (n = 7 mice/group; 10-12 months). c Immunoblots of brain homogenates of ntg, untreated and anle138b-treated PS19 mice probed with the phosphorylation-specific antibodies (AT8 and AT180) and phosphorylation-independent antibody E178. d Densitometric analysis of immunoblots showing phosphorylated tau (AT8, AT180) in untreated and anle138b-treated PS19 mice. (n = 10–11 mice/group; 10–12 months). Immunoblots using the antibodies HT7 and AT100 (e) and densitometric analysis (f) of sarkosyl-insoluble aggregated tau protein in the brain of untreated PS19 transgenic mice in comparison to anle138b-treated animals. (n = 9–10 mice/group; 10–12 months). Immunoblots of sucrose-gradient centrifugation fractions from untreated and anle138b-treated mouse brain homogenates, to separate tau aggregates according to their molecular weight (g) and densitometric analysis (h). Anle138b-treated PS19 mice showed a significant reduction of high molecular weight species in the 50 % sucrose fraction in comparison to untreated animals (n = 7 mice/group; 10–12 months). Asterisks indicate significant differences relative to untreated PS19 mice (*p < 0.05; t test)
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Fig3: Anle138b reduces insoluble tau levels in PS19 mice a Immunoblots of brain homogenates of non-transgenic (ntg), untreated and anle138b-treated PS19 mice probed with HT7 and E178 antibody detecting total tau. b Densitometric analysis of immunoblots showing the brain protein levels of total tau (HT7 and E178) in untreated and anle138b-treated PS19 mice. (n = 7 mice/group; 10-12 months). c Immunoblots of brain homogenates of ntg, untreated and anle138b-treated PS19 mice probed with the phosphorylation-specific antibodies (AT8 and AT180) and phosphorylation-independent antibody E178. d Densitometric analysis of immunoblots showing phosphorylated tau (AT8, AT180) in untreated and anle138b-treated PS19 mice. (n = 10–11 mice/group; 10–12 months). Immunoblots using the antibodies HT7 and AT100 (e) and densitometric analysis (f) of sarkosyl-insoluble aggregated tau protein in the brain of untreated PS19 transgenic mice in comparison to anle138b-treated animals. (n = 9–10 mice/group; 10–12 months). Immunoblots of sucrose-gradient centrifugation fractions from untreated and anle138b-treated mouse brain homogenates, to separate tau aggregates according to their molecular weight (g) and densitometric analysis (h). Anle138b-treated PS19 mice showed a significant reduction of high molecular weight species in the 50 % sucrose fraction in comparison to untreated animals (n = 7 mice/group; 10–12 months). Asterisks indicate significant differences relative to untreated PS19 mice (*p < 0.05; t test)

Mentions: Subsequently, we examined the levels of total and insoluble tau in the brains of PS19 mice using multiple tau antibodies. Similar levels of total tau observed in treated and untreated mice using the tau antibodies HT7 and E178 exclude a treatment-induced suppression of tau expression (Fig. 3a, b). Quantification with phosphorylation-specific antibodies showed that the level of phosphorylated tau at the AT8 site (Ser202 + Thr205) is reduced, whereas the tau levels at the AT180 site (Thr231) are unaltered (Fig. 3c, d). To further evaluate, whether anle138b treatment affected the level of aggregated insoluble tau in vivo, we measured the levels of sarkosyl-insoluble tau after ultracentrifugation. Non-transgenic mice exhibited no insoluble tau either probed with the HT7 or AT100 antibody (Fig. 3e). Administration of anle138b significantly reduced the amount of the sarkosyl-insoluble tau (HT7 and AT100) in brains of 10- to 12-month-old PS19 mice compared to untreated mice (Fig. 3e, f). We next tested whether anle138b treatment influenced the size distribution of aggregated tau protein in the brain of PS19 mice. Therefore, we separated tau aggregates depending on their molecular weight in a sucrose gradient (containing 1 % sarkosyl) by ultracentrifugation (Fig. 3g). Soluble tau (composed mainly of 63 kDa tau) was detected in the 20 % sucrose fraction and was unchanged between treated and untreated mice (Fig. 3g, h). Lower to higher molecular weight aggregates (30–50 % sucrose) primarily contained insoluble 64 kDa tau (Fig. 3e). Anle138b altered the size distribution of tau aggregates and significantly reduced larger insoluble tau species in the 50 % sucrose fraction in relation to untreated animals (Fig. 3g, h). However, lower molecular weight tau aggregates (30–40 % sucrose) remained unchanged (Fig. 3g, h). Summarizing, the histological and biochemical data indicate that anle138b inhibits the formation of pathological higher molecular weight tau aggregates in vivo.Fig. 3


Reducing tau aggregates with anle138b delays disease progression in a mouse model of tauopathies.

Wagner J, Krauss S, Shi S, Ryazanov S, Steffen J, Miklitz C, Leonov A, Kleinknecht A, Göricke B, Weishaupt JH, Weckbecker D, Reiner AM, Zinth W, Levin J, Ehninger D, Remy S, Kretzschmar HA, Griesinger C, Giese A, Fuhrmann M - Acta Neuropathol. (2015)

Anle138b reduces insoluble tau levels in PS19 mice a Immunoblots of brain homogenates of non-transgenic (ntg), untreated and anle138b-treated PS19 mice probed with HT7 and E178 antibody detecting total tau. b Densitometric analysis of immunoblots showing the brain protein levels of total tau (HT7 and E178) in untreated and anle138b-treated PS19 mice. (n = 7 mice/group; 10-12 months). c Immunoblots of brain homogenates of ntg, untreated and anle138b-treated PS19 mice probed with the phosphorylation-specific antibodies (AT8 and AT180) and phosphorylation-independent antibody E178. d Densitometric analysis of immunoblots showing phosphorylated tau (AT8, AT180) in untreated and anle138b-treated PS19 mice. (n = 10–11 mice/group; 10–12 months). Immunoblots using the antibodies HT7 and AT100 (e) and densitometric analysis (f) of sarkosyl-insoluble aggregated tau protein in the brain of untreated PS19 transgenic mice in comparison to anle138b-treated animals. (n = 9–10 mice/group; 10–12 months). Immunoblots of sucrose-gradient centrifugation fractions from untreated and anle138b-treated mouse brain homogenates, to separate tau aggregates according to their molecular weight (g) and densitometric analysis (h). Anle138b-treated PS19 mice showed a significant reduction of high molecular weight species in the 50 % sucrose fraction in comparison to untreated animals (n = 7 mice/group; 10–12 months). Asterisks indicate significant differences relative to untreated PS19 mice (*p < 0.05; t test)
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Fig3: Anle138b reduces insoluble tau levels in PS19 mice a Immunoblots of brain homogenates of non-transgenic (ntg), untreated and anle138b-treated PS19 mice probed with HT7 and E178 antibody detecting total tau. b Densitometric analysis of immunoblots showing the brain protein levels of total tau (HT7 and E178) in untreated and anle138b-treated PS19 mice. (n = 7 mice/group; 10-12 months). c Immunoblots of brain homogenates of ntg, untreated and anle138b-treated PS19 mice probed with the phosphorylation-specific antibodies (AT8 and AT180) and phosphorylation-independent antibody E178. d Densitometric analysis of immunoblots showing phosphorylated tau (AT8, AT180) in untreated and anle138b-treated PS19 mice. (n = 10–11 mice/group; 10–12 months). Immunoblots using the antibodies HT7 and AT100 (e) and densitometric analysis (f) of sarkosyl-insoluble aggregated tau protein in the brain of untreated PS19 transgenic mice in comparison to anle138b-treated animals. (n = 9–10 mice/group; 10–12 months). Immunoblots of sucrose-gradient centrifugation fractions from untreated and anle138b-treated mouse brain homogenates, to separate tau aggregates according to their molecular weight (g) and densitometric analysis (h). Anle138b-treated PS19 mice showed a significant reduction of high molecular weight species in the 50 % sucrose fraction in comparison to untreated animals (n = 7 mice/group; 10–12 months). Asterisks indicate significant differences relative to untreated PS19 mice (*p < 0.05; t test)
Mentions: Subsequently, we examined the levels of total and insoluble tau in the brains of PS19 mice using multiple tau antibodies. Similar levels of total tau observed in treated and untreated mice using the tau antibodies HT7 and E178 exclude a treatment-induced suppression of tau expression (Fig. 3a, b). Quantification with phosphorylation-specific antibodies showed that the level of phosphorylated tau at the AT8 site (Ser202 + Thr205) is reduced, whereas the tau levels at the AT180 site (Thr231) are unaltered (Fig. 3c, d). To further evaluate, whether anle138b treatment affected the level of aggregated insoluble tau in vivo, we measured the levels of sarkosyl-insoluble tau after ultracentrifugation. Non-transgenic mice exhibited no insoluble tau either probed with the HT7 or AT100 antibody (Fig. 3e). Administration of anle138b significantly reduced the amount of the sarkosyl-insoluble tau (HT7 and AT100) in brains of 10- to 12-month-old PS19 mice compared to untreated mice (Fig. 3e, f). We next tested whether anle138b treatment influenced the size distribution of aggregated tau protein in the brain of PS19 mice. Therefore, we separated tau aggregates depending on their molecular weight in a sucrose gradient (containing 1 % sarkosyl) by ultracentrifugation (Fig. 3g). Soluble tau (composed mainly of 63 kDa tau) was detected in the 20 % sucrose fraction and was unchanged between treated and untreated mice (Fig. 3g, h). Lower to higher molecular weight aggregates (30–50 % sucrose) primarily contained insoluble 64 kDa tau (Fig. 3e). Anle138b altered the size distribution of tau aggregates and significantly reduced larger insoluble tau species in the 50 % sucrose fraction in relation to untreated animals (Fig. 3g, h). However, lower molecular weight tau aggregates (30–40 % sucrose) remained unchanged (Fig. 3g, h). Summarizing, the histological and biochemical data indicate that anle138b inhibits the formation of pathological higher molecular weight tau aggregates in vivo.Fig. 3

Bottom Line: Here, we show that the di-phenyl-pyrazole anle138b binds to aggregated tau and inhibits tau aggregation in vitro and in vivo.In addition, we found decreased synapse and neuron loss accompanied by a decreased gliosis in the hippocampus.Our results suggest that reducing tau aggregates with anle138b may represent an effective and promising approach for the treatment of human tauopathies.

View Article: PubMed Central - PubMed

Affiliation: German Center for Neurodegenerative Diseases (DZNE), Ludwig-Erhard-Allee 2, 53175, Bonn, Germany.

ABSTRACT
Pathological tau aggregation leads to filamentous tau inclusions and characterizes neurodegenerative tauopathies such as Alzheimer's disease and frontotemporal dementia and parkinsonism linked to chromosome 17. Tau aggregation coincides with clinical symptoms and is thought to mediate neurodegeneration. Transgenic mice overexpressing mutant human P301S tau exhibit many neuropathological features of human tauopathies including behavioral deficits and increased mortality. Here, we show that the di-phenyl-pyrazole anle138b binds to aggregated tau and inhibits tau aggregation in vitro and in vivo. Furthermore, anle138b treatment effectively ameliorates disease symptoms, increases survival time and improves cognition of tau transgenic PS19 mice. In addition, we found decreased synapse and neuron loss accompanied by a decreased gliosis in the hippocampus. Our results suggest that reducing tau aggregates with anle138b may represent an effective and promising approach for the treatment of human tauopathies.

No MeSH data available.


Related in: MedlinePlus