Learn More
Hyperhomocysteinemia increases the risk of Alzheimer's disease (AD), but the mechanism is elusive. Here, we found that high plasma homocysteine induced by vena caudalis injection for 2 weeks could induce AD-like tau hyperphosphorylation at multiple sites in rat brain hippocampus. Homocysteine inhibited the activity of protein phosphatase 2A (PP2A) with a(More)
Protein phosphatase-2A (PP2A) activity is significantly suppressed in Alzheimer's disease. We have reported that glycogen synthase kinase-3β (GSK-3β) inhibits PP2A via upregulating the phosphorylation of PP2A catalytic subunit (PP2A(C)). Here we studied the effects of GSK-3β on the inhibitory demethylation of PP2A at leucine-309 (dmL309-PP2A(C)). We found(More)
Hyperhomocysteinemia is associated with an increased risk of Alzheimer's disease (AD). Our previous work has demonstrated that combined folate and vitamin B12 (vit-B12) supplementation prevents tau hyperphosphorylation and memory deficits induced by acute administration of homocysteine in young rats. Here, we further investigated whether folate/vit-B12(More)
The intracellular accumulation of hyperphosphorylated tau plays a crucial role in neurodegeneration of Alzheimer's disease (AD), but the mechanism is not fully understood. From the observation that tau hyperphosphorylation renders cells more resistant to chemically-induced cell apoptosis, we have proposed that tau-involved apoptotic abortion may be the(More)
PDMS/ceramic composite membrane was directly integrated with acetone-butanol-ethanol (ABE) fermentation using Clostridium acetobutylicum XY16 at 37 °C and in situ removing ABE from fermentation broth. The membrane was integrated with batch fermentation, and approximately 46 % solvent was extracted. The solvent in permeates was 118 g/L, and solvent(More)
The activity of protein phosphatase-2A (PP-2A) is significantly suppressed in the brain of Alzheimer's disease (AD) patients, but the mechanism is not understood. Here, we found an in vivo association of glycogen synthase kinase 3beta (GSK-3beta) with inhibitor-2 of PP-2A (I(2)(PP-2A)). The activation of GSK-3 resulted in accumulation of I(2)(PP-2A) with(More)
A chronic neuron loss is the cardinal pathology in Alzheimer disease (AD), but it is still not understood why most neurons in AD brain do not accomplish apoptosis even though they are actually exposed to an environment with enriched proapoptotic factors. Protein phosphatase-2A inhibitor-2 (I(2)(PP2A)), an endogenous PP2A inhibitor, is significantly(More)
GSK-3β (glycogen synthase kinase-3β), a crucial tau kinase, negatively regulates PP2A (protein phosphatase 2A), the most active tau phosphatase that is suppressed in the brain in AD (Alzheimer's disease). However, the molecular mechanism is not understood. In the present study we found that activation of GSK-3β stimulates the inhibitory phosphorylation of(More)
Hyperhomocysteinemia (Hhcy) may induce memory deficits with β-amyloid (Aβ) accumulation and tau hyperphosphorylation. Simultaneous supplement of folate and vitamin B12 partially restored the plasma homocysteine level and attenuated tau hyperphosphorylation, Aβ accumulation and memory impairments induced by Hhcy. However, folate and vitamin B12 treatment(More)
Dysfunction of proteasome contributes to the accumulation of the abnormally hyperphosphorylated tau in Alzheimer's disease. However, whether tau hyperphosphorylation and accumulation affect the activity of proteasome is elusive. Here we found that a moderate tau phosphorylation activated the trypsin-like activity of proteasome, whereas further(More)