title: Enhanced Activities of Blood Thiamine Diphosphatase and Monophosphatase in Alzheimer's Disease.
abstract: Thiamine metabolites and activities of thiamine-dependent enzymes are impaired in Alzheimer's disease (AD).
  
  
  
  To clarify the mechanism for the reduction of thiamine diphosphate (TDP), an active form of thiamine and critical coenzyme of glucose metabolism, in AD.
  
  
  
  Forty-five AD patients clinically diagnosed and 38 age- and gender-matched control subjects without dementia were voluntarily recruited. The contents of blood TDP, thiamine monophosphate (TMP), and thiamine, as well as the activities of thiamine diphosphatase (TDPase), thiamine monophosphatase (TMPase), and thiamine pyrophosphokinase (TPK), were assayed by high performance liquid chromatography.
  
  
  
  Blood TDP contents of AD patients were significantly lower than those in control subjects (79.03 ± 23.24 vs. 127.60 ± 22.65 nmol/L, P<0.0001). Activities of TDPase and TMPase were significantly enhanced in AD patients than those in control subjects (TDPase: 1.24 ± 0.08 vs. 1.00 ± 0.04, P < 0.05; TMPase: 1.22 ± 0.04 vs. 1.00 ± 0.06, P < 0.01). TPK activity remained unchanged in AD as compared with that in control (0.93 ± 0.04 vs. 1.00 ± 0.04, P > 0.05). Blood TDP levels correlated negatively with TDPase activities (r = -0.2576, P = 0.0187) and positively with TPK activities (r = 0.2426, P = 0.0271) in all participants.
  
  
  
  Enhanced TDPase and TMPase activities may contribute to the reduction of TDP level in AD patients. The results imply that an imbalance of phosphorylation-dephosphorylation related to thiamine and glucose metabolism may be a potential target for AD prevention and therapy.
authors.affiliation: Department of Neurology, Zhongshan Hospital & Shanghai Medical College, Fudan University, Shanghai, China.|State Key Laboratory of Medical Neurobiology, Institutes of Brain Science & Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, China.
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Pan
authors.affiliation: Department of Neurology, Zhongshan Hospital & Shanghai Medical College, Fudan University, Shanghai, China.|State Key Laboratory of Medical Neurobiology, Institutes of Brain Science & Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, China.
authors.forename: Shaoming
authors.initials: S
authors.lastname: Sang
authors.affiliation: Department of Neurology, Zhongshan Hospital & Shanghai Medical College, Fudan University, Shanghai, China.
authors.forename: Guoqiang
authors.initials: G
authors.lastname: Fei
authors.affiliation: Department of Neurology, Zhongshan Hospital & Shanghai Medical College, Fudan University, Shanghai, China.
authors.forename: Lirong
authors.initials: L
authors.lastname: Jin
authors.affiliation: State Key Laboratory of Medical Neurobiology, Institutes of Brain Science & Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, China.
authors.forename: Huimin
authors.initials: H
authors.lastname: Liu
authors.affiliation: Regional Health Service Center of Xujiahui, Xuhui District, Shanghai, China.
authors.forename: Zhiliang
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Regional Health Service Center of Xujiahui, Xuhui District, Shanghai, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Wang
authors.affiliation: Department of Neurology, Zhongshan Hospital & Shanghai Medical College, Fudan University, Shanghai, China.|State Key Laboratory of Medical Neurobiology, Institutes of Brain Science & Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, China.
authors.forename: Chunjiu
authors.initials: C
authors.lastname: Zhong
mesh_terms: D017766:Acid Anhydride Hydrolases / Q000097:blood*; D000368:Aged; D000369:Aged, 80 and over; D000483:Alleles; D000544:Alzheimer Disease / Q000097:blood* / Q000175:diagnosis / Q000235:genetics; D001057:Apolipoproteins E / Q000235:genetics / Q000378:metabolism; D015415:Biomarkers; D001786:Blood Glucose; D016022:Case-Control Studies; D002851:Chromatography, High Pressure Liquid; D005215:Fasting; D005260:Female; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D010744:Phosphoric Monoester Hydrolases / Q000097:blood*; D013836:Thiamin Pyrophosphokinase / Q000097:blood; D013831:Thiamine / Q000097:blood; D013833:Thiamine Monophosphate / Q000097:blood
chemical_list: D001057:Apolipoproteins E; D015415:Biomarkers; D001786:Blood Glucose; D013833:Thiamine Monophosphate; D013836:Thiamin Pyrophosphokinase; C022734:thiamine monophosphatase; D010744:Phosphoric Monoester Hydrolases; D017766:Acid Anhydride Hydrolases; C023837:nucleoside-diphosphatase; D013831:Thiamine