Expression of the alpha-5(IV) collagen chain in the fetal human small intestine.
OBJECTIVE
The basement membrane type IV collagen is a family composed of at least five genetically distinct but structurally similar polypeptide chains, alpha 1-alpha 5. The alpha 1(IV) and alpha 2(IV) chains are ubiquitous components of basement membranes, whereas the alpha 3(IV), alpha 4(IV), and alpha 5(IV) chains have a restricted tissue distribution. The aim of this study was to analyze the presence of these minor type IV collagen chains in the small intestinal mucosa.


METHODS
The expression of type IV collagen chains in the developing and adult human small intestine was determined by indirect immunofluorescence with monoclonal and polyclonal antibodies. Western blotting and Northern hybridization analysis were also used to additionally investigate the expression of the alpha 1(IV) and alpha 5(IV) chains.


RESULTS
The alpha 3-alpha 5(IV) chains were absent from the adult epithelium, but, surprisingly, the alpha 5(IV) chain was consistently detected in the fetal mucosa. Its expression was confirmed by Western blotting, complementary DNA polymerase chain-reaction amplification, and Northern hybridization analysis.


CONCLUSIONS
The alpha 5(IV) chain of collagen is expressed in the fetal but not adult human intestinal epithelium. Its position at the basolateral domain of epithelial cells suggests a potential role for this molecule during development.
Beaulieu
J F
JF
Département d'Anatomie et de Biologie Cellulaire, Faculté de Médecine, Université de Sherbrooke, Québec, Canada.
Vachon
P H
PH
Herring-Gillam
F E
FE
Simoneau
A
A
Perreault
N
N
Asselin
C
C
Durand
J
J
D000375:Aging / Q000378:metabolism; D001483:Base Sequence; D003094:Collagen / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D005333:Fetus / Q000378:metabolism*; D005455:Fluorescent Antibody Technique; D006801:Humans; D007421:Intestine, Small / Q000196:embryology* / Q000378:metabolism; D015335:Molecular Probes / Q000235:genetics; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism
D015335:Molecular Probes; D010446:Peptide Fragments; D012333:RNA, Messenger; D003094:Collagen