Up-regulation of surfactant protein A in chronic sialadenitis.
OBJECTIVE
Salivary secretions play a critical role in maintaining the health of the oral cavity, which is the first gate of entry to the airways and thus is exposed to a variety of environmental insults. Surfactant protein A (SP-A) is a member of the collectin family and plays an important role in first-line airway defense. The objectives of this study were to examine the expression of SP-A messenger RNA and protein in human salivary glands and to investigate its up-regulation during inflammatory conditions.


METHODS
Reverse transcription-polymerase chain reaction was performed on salivary gland tissues from patients and a control group. The expression levels of SP-A to GAPDH (glyceraldehyde-3-phosphate dehydrogenase) transcripts were semiquantified by densitometry. We also characterized the cellular localizations of SP-A protein immunohistochemically.


METHODS
Tertiary academic institution.


METHODS
Ten patients with chronic sialadenitis and 10 patients with healthy salivary glands.


RESULTS
Surfactant protein A messenger RNA and protein were detected in glands of patients who were healthy and in those with chronic sialadenitis. The expression levels of SP-A messenger RNA in the salivary glands of patients with chronic sialadenitis was significantly increased compared with those in healthy salivary glands. Immunohistochemical staining revealed SP-A immunoreactivity in the ductal epithelia of healthy salivary glands and in the salivary glands of those with chronic sialadenitis, and stronger immunoreactivity was observed in those with chronic sialadenitis tissues.


CONCLUSIONS
Surfactant protein A is present in the salivary gland epithelium and is up-regulated in individuals with chronic sialadenitis. These results suggest that salivary gland SP-A may play an important role in the innate host defense of human salivary glands.
Lee
Heung-Man
HM
Department of Otorhinolaryngology-Head and Neck Surgery, Communication Disorder Institute of Medical Science Research Center, Korea University College of Medicine, Seoul, South Korea. lhman@korea.ac.kr
Park
Il-Ho
IH
Woo
Jeong-Soo
JS
Chae
Sung Won
SW
Kang
Hee Joon
HJ
Hwang
Soon Jae
SJ
D002908:Chronic Disease; D004848:Epithelium / Q000378:metabolism; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D037662:Pulmonary Surfactant-Associated Protein A / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012469:Salivary Glands / Q000378:metabolism*; D012793:Sialadenitis / Q000378:metabolism*; D015854:Up-Regulation
D037662:Pulmonary Surfactant-Associated Protein A; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases