Connexin43 plays an important role in lung development.
OBJECTIVE
Connexin43 (Cx43) is one of the proteins associated with gap junction. Connexin43 knockout mice die after birth owing to hypoplastic lungs. The purpose of this study was to analyze the hypoplastic lung of Cx43 knockout mice to clarify the role of the Cx43 during lung development.


METHODS
Adult hetero Cx43 mice were mated. Newborn mice were divided into the following groups: wild, hetero, and knockout. Total RNA was extracted from the right lung, and the left lung was fixed for immunohistochemical staining. The mRNA expression of surfactant protein C, aquaporin-5, and alpha-smooth muscle actin were analyzed by reverse transcriptase polymerase chain reaction. H&E and immunohistochemical staining for those markers were performed.


RESULTS
The mRNA expression of aquaporin-5, surfactant protein C, and alpha-smooth muscle actin was significantly lower in knockout mice than that in the wild and hetero mice. H&E staining in the knockout mice showed narrow airspaces and thicker interalveolar septae. Immunohistochemical staining in all markers showed the formation of alveoli to be delayed in the knockout mice.


CONCLUSIONS
Based on these findings, Cx43 is closely related to alveolar and vascular formation during lung development.
Nagata
Kouji
K
Department of Pediatric Surgery, Reproductive and Developmental Medicine, Kyushu University, Fukuoka 812-8582, Japan. koujin@pedsurg.med.kyushu-u.ac.jp
Masumoto
Kouji
K
Esumi
Genshirou
G
Teshiba
Risa
R
Yoshizaki
Keigo
K
Fukumoto
Satoshi
S
Nonaka
Kazuaki
K
Taguchi
Tomoaki
T
D000199:Actins / Q000235:genetics / Q000502:physiology; D000818:Animals; D051402:Aquaporin 5 / Q000235:genetics / Q000502:physiology; D018031:Connexin 43 / Q000235:genetics / Q000502:physiology*; D017630:Connexins / Q000235:genetics / Q000502:physiology; D018507:Gene Expression Regulation, Developmental / Q000235:genetics / Q000502:physiology; D007150:Immunohistochemistry; D036341:Intercellular Signaling Peptides and Proteins; D008168:Lung / Q000002:abnormalities / Q000254:growth & development* / Q000473:pathology; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009130:Muscle, Smooth / Q000254:growth & development; D010455:Peptides / Q000235:genetics / Q000502:physiology; D011650:Pulmonary Alveoli / Q000254:growth & development; D037721:Pulmonary Surfactant-Associated Protein C; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000706:statistics & numerical data
C558396:Acta2 protein, mouse; D000199:Actins; D051402:Aquaporin 5; D018031:Connexin 43; D017630:Connexins; D036341:Intercellular Signaling Peptides and Proteins; D010455:Peptides; D037721:Pulmonary Surfactant-Associated Protein C; D012333:RNA, Messenger; C489680:Sftpc protein, mouse