Advanced glycation end products induce brain-derived neurotrophic factor release from human platelets through the Src-family kinase activation.
Brain-derived neurotrophic factor (BDNF) exerts beneficial effects not only on diabetic neuropathies but also on cardiovascular injury. There is argument regarding the levels of serum BDNF in patients with diabetes mellitus (DM). Because BDNF in peripheral blood is rich in platelets, this may represent dysregulation of BDNF release from platelets. Here we focused on advanced glycation end products (AGEs), which are elevated in patients with DM and have adverse effects on cardiovascular functions. The aim of this study is to elucidate the role of AGEs in the regulation of BDNF release from human platelets.



Platelets collected from peripheral blood of healthy volunteers were incubated with various concentrations of AGE (glycated-BSA) at 37 °C for 5 min with or without BAPTA-AM, a cell permeable Ca2+chelator, or PP2, a potent inhibitor of Src family kinases (SFKs). Released and cellular BDNF were measured by ELISA and calculated. Phosphorylation of Src and Syk, a downstream kinase of SFKs, in stimulated platelets was examined by Western blotting and immunoprecipitation.



AGE induced BDNF release from human platelets in a dose-dependent manner, which was dependent on intracellular Ca2+and SFKs. We found that AGE induced phosphorylation of Src and Syk.



AGE induces BDNF release from human platelets through the activation of the Src-Syk-(possibly phospholipase C)-Ca2+pathway. Considering the toxic action of AGEs and the protective roles of BDNF, it can be hypothesized that AGE-induced BDNF release is a biological defense system in the early phase of diabetes. Chronic elevation of AGEs may induce depletion or downregulation of BDNF in platelets during the progression of DM.
Department of Molecular Neurobiology, Brain Research Institute, Niigata University, Asahimachi, Niigata, 951-8585, Japan.|Department of Hematology, Endocrinology and Metabolism, Niigata University Faculty of Medicine, Niigata, Japan.
Kazuo
K
Furukawa
Japanese Red Cross Niigata Blood Center, Niigata, Japan.
Ichiro
I
Fuse
Department of Molecular Neurobiology, Brain Research Institute, Niigata University, Asahimachi, Niigata, 951-8585, Japan.
Yuriko
Y
Iwakura
Department of Molecular Neurobiology, Brain Research Institute, Niigata University, Asahimachi, Niigata, 951-8585, Japan.
Hidekazu
H
Sotoyama
Department of Hematology, Endocrinology and Metabolism, Niigata University Faculty of Medicine, Niigata, Japan.
Osamu
O
Hanyu
Department of Molecular Neurobiology, Brain Research Institute, Niigata University, Asahimachi, Niigata, 951-8585, Japan.
Hiroyuki
H
Nawa
Department of Hematology, Endocrinology and Metabolism, Niigata University Faculty of Medicine, Niigata, Japan.
Hirohito
H
Sone
Department of Molecular Neurobiology, Brain Research Institute, Niigata University, Asahimachi, Niigata, 951-8585, Japan. nobtak@bri.niigata-u.ac.jp.
Nobuyuki
0000-0002-6122-939X
N
Takei
D000328:Adult; D001792:Blood Platelets / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D019208:Brain-Derived Neurotrophic Factor / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation; D017127:Glycation End Products, Advanced / Q000494:pharmacology*; D006801:Humans; D008875:Middle Aged; D010766:Phosphorylation; D012710:Serum Albumin, Bovine / Q000494:pharmacology*; D000072377:Syk Kinase / Q000378:metabolism; D010738:Type C Phospholipases / Q000378:metabolism; D019061:src-Family Kinases / Q000378:metabolism*
D019208:Brain-Derived Neurotrophic Factor; D017127:Glycation End Products, Advanced; D012710:Serum Albumin, Bovine; C579455:BDNF protein, human; C000606896:SYK protein, human; D000072377:Syk Kinase; D019061:src-Family Kinases; D010738:Type C Phospholipases; D002118:Calcium
AGE; BDNF; Ca2+; Platelets; Release; Src family kinases; Syk