Antisense inhibition of transglutaminase 2 affects
development of mouse embryo submandibular
gland in organ culture
Suk Keun Lee
a
, Yeon Sook Kim
a
, Sang Shin Lee
a
, Young Joon Lee
a
,
In Sun Song
a
, Sang Chul Park
b
, Je Geun Chi
c
, Soo Il Chung
a,
*
a
Department of Oral Pathology, College of Dentistry, Kangnung National University, Gangneung, 210-702,
Republic of Korea
b
Department of Biochemistry, Seoul National University College of Medicine, Seoul, Republic of Korea
c
Department of Pathology, Seoul National University College of Medicine, Seoul, Republic of Korea
Accepted 24 January 2005
Archives of Oral Biology (2005) 50, 789—798
www.intl.elsevierhealth.com/journals/arob
KEYWORDS
Transglutaminase 2;
Antisense inhibition;
Submandibular gland;
Mouse embryo
Summary Tissue transglutaminase (TGase 2) has been implicated in numerous
cellular functions, i.e., apoptosis, differentiation, extracellular matrix protein
cross-linking and organogenesis. Earlier report of the strong transient expression
of TGase 2 localized at the anchoring sites of muscle bundles of human embryo and
recent findings of a similar transient expression of the TGase 2 in the salivary
myoepithelial cells of mouse embryo indicated a definitive role of TGase 2 in the
cytodifferentiation of myoepithelial cells. To understand functional role(s) of TGase 2
in the organogenesis of salivary gland, antisense inhibition of TGase 2 expression was
performed in the organ culture of mouse embryo submandibular gland. The antisense
of TGase 2 transfection tested using oral keratinocyte cell line, KB cells, elicited
significant inhibition of cellular transglutaminase expression. The same antisense
treatment of submandibular glands in organ culture also resulted in the suppression of
cellular TGase 2 expression as indicated by weak immunoreaction against anti-TGase
2 in the myoepithelial cells of submandibular glands in contrast to strong reaction in
those of the normal and sense-treated glands. Antisense to TGase 2 treatment
induced retarded growth of salivary epithelium in 1 week and severe aberrant growth
of salivary ducts and acini in 2 weeks and also expression of apoptotic inducer, Bax
specifically localized in the myoepithelial cells, suggesting apoptotic state of myoe-
pithelial cells. These data suggest that the antisense inhibition of TGase 2 expression
affects the cytodifferentiation of ductal cells and myoepithelial cells, and resulted in
severe retardation of tubuloalveolar structure formation of salivary gland.
# 2005 Elsevier Ltd. All rights reserved.
Abbreviations: TGase 2, tissue transglutaminase; a-SMA, a-smooth muscle actin; E13, 13 days old mouse embryo; DTT, dithio-
threitol; PCNA, proliferating cell nuclear antigen
* Corresponding author. Tel.: +82 33 640 2228; fax: +82 33 642 6410.
E-mail address: rchung@kangnung.ac.kr (S.I. Chung).
0003–9969/$ — see front matter # 2005 Elsevier Ltd. All rights reserved.
doi:10.1016/j.archoralbio.2005.01.007