Identifying sources and estimating glandular output of salivary TIMP-1.
OBJECTIVE
Tissue inhibitor of metalloproteinases 1 (TIMP-1) has been identified as a potential biomarker in diseases such as cancer, cardiovascular diseases and diabetes. Since TIMP-1 resides in most tissues and bodily fluids, we evaluated the potential of using saliva to obtain reproducible TIMP-1 measurements in a non-invasive manner.


METHODS
Samples of unstimulated and stimulated whole saliva and saliva collected from individual glands were analysed for TIMP-1 content. A TIMP-1 ELISA was validated for use in saliva testing and the most optimal sampling and handling procedures for reproducible measurements identified. Western blotting and MALDI-TOF mass spectrometry were used for confirmatory analyses.


RESULTS
The TIMP-1 ELISA was found suitable for saliva measurements. All saliva secretions contained TIMP-1, but in different concentrations ranging from 2.81 ng/mL in submandibular/sublingual saliva to 173.88 ng/mL in parotid saliva. TIMP-1 concentrations were influenced to a varying degree by fluctuations in flow. We found the lowest output in submandibular/sublingual saliva stimulated with 0.5% citric acid (3.56 ng/min) and highest output in chewing-stimulated whole saliva (267.01 ng/min).


CONCLUSIONS
This study shows that saliva contains authentic TIMP-1, the concentration of which was found to depend on gland type and salivary flow. Stimulated whole saliva is suggested as a reliable and easily accessible source for TIMP-1 determinations in bodily fluids.
Holten-Andersen
L
L
Department of Oral Medicine, Clinical Oral Physiology, Oral Pathology & Anatomy, Institute of Odontology, Faculty of Health Sciences, University of Copenhagen, Copenhagen N, Denmark. lho@odont.ku.dk
Jensen
S Beier
SB
Bardow
A
A
Harslund
J
J
Thaysen-Andersen
M
M
Lademann
U
U
Usher
P Autzen
PA
Offenberg
H
H
Højrup
P
P
Reibel
J
J
Nielsen
H J
HJ
Brünner
N
N
Nauntofte
B
B
D005260:Female; D006801:Humans; D008297:Male; D008409:Mastication; D010306:Parotid Gland / Q000737:chemistry / Q000378:metabolism*; D012463:Saliva / Q000737:chemistry*; D012470:Salivary Glands, Minor / Q000378:metabolism; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000378:metabolism*
D019715:Tissue Inhibitor of Metalloproteinase-1