Expression of transforming growth factor [beta] type ii receptor in
rat lung.
Development, Is Regulated During.
Yun Zhao, and Stephen L. Young
APStracts 2:0073L, 1995.
Transforming growth factor [beta] (TGF-[beta]) is an
autocrine/paracrine growth factor that regulates cell proliferation,
differentiation, extracellular matrix production and various other
cell functions in the lung. TGF-[beta] exerts its effects on cells by
binding to transmembrane heteromeric serine/threonine kinase
receptors. The expression and localization of specific TGF-[beta]
receptors in the lung, however, have not yet been investigated. In
the present studies, we isolated a 1762 base pair cDNA containing the
full length coding sequence for TGF-[beta] type II receptor
(T[beta]RII) from rat fetal lung by using polymerase chain reaction
methods. The expression of T[beta]RII during lung development was
examined by Northern analysis. A 5.1 kilobase T[beta]RII mRNA was
detected in rat lung tissue. T[beta]RII mRNA was expressed in rat
fetal lung tissue early in development, increased as development
proceeds, reached maximal concentration postnatally and then
decreased to the adult level. The localization of T[beta]RII in fetal
and postnatal rat lung tissue was investigated by using in situ
hybridization performed with an antisense RNA probe. T[beta]RII gene
was expressed in the mesenchymal tissue and in the epithelial lining
of the developing air way at day 16 of gestation. The hybridization
signal of T[beta]RII mRNA was also observed in the adventitial layer
of small blood vessels. Expression of T[beta]RII gene in the
developing airway epithelium occurred along a proximal-distal
gradient. In postnatal lung, T[beta]RII mRNA was detected mainly in
parenchymal tissues and blood vessels. Expression of T[beta]RII
remained high in the interstitium of interalveolar septa. These data
provide direct evidence that T[beta]RII is regulated during lung
development. The temporal and spatial distribution of T[beta]RII mRNA
in rat lung tissues suggests that TGF-[beta] plays a role as a
multifunctional regulator of epithelial-mesenchymal interactions
during lung development.
Received 30 January 1995; accepted in final form 26 April 1995.
APS Manuscript Number L27-5.
Article publication pending Am. J. Physiol. (Lung Cell. Mol.
Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 9 May 1995.