Title : Identification of pro- and mature brain-derived neurotrophic factor in human saliva
Abstract :
OBJECTIVE: Growth factors , including brain-derived neurotrophic factor ( BDNF ), are polypeptides that are involved in the maintenance, survival, and death of central and peripheral cells
Numerous growth factors have been identified in saliva and are thought to promote wound healing and maintenance of the oral epithelium
The aim of this study was to determine if BDNF is also found in human saliva
METHODS: Whole, unstimulated saliva samples (n = 30) were analyzed by SDS-PAGE and Western blot using an anti-human BDNF antibody
Proteolytic cleavage products were similarly assessed following the incubation of pooled saliva with N-glycanase F and plasmin
Subjects were also genotyped for the BDNF Val66Met single nucleotide polymorphism (SNP)
RESULTS: These experiments revealed the presence of immunoreactive bands at 14, 32 and 34 kDa, corresponding to mature ( mBDNF ) and pro BDNF , as well as a truncated pro-form at 24 kDa
Not every sample contained all forms of BDNF
Treatment with N-glycanase and plasmin reduced the size of the higher molecular weight bands, confirming the glycosylated pro-form of BDNF
mBDNF was detected significantly less often in subjects with the Val66Met SNP, compared to those without the polymorphism (chi(2) = 4.05; P < 0.05)
CONCLUSIONS: While the function of salivary BDNF still requires elucidation, these findings suggest that it may be possible to use saliva in lieu of blood in future studies of BDNF and the Val66Met polymorphism