title: Cloning of the mouse laminin alpha 4 cDNA. Expression in a subset of endothelium.
abstract: Endothelial cells express a 400-kDa or 240-kDa laminin alpha chain, depending on their tissue of origin or physiological state [1, 2]. Using differential display and subsequent screening of a mouse endothelial cell cDNA library we here identify the gene coding for the 240-kDa laminin chain as the laminin alpha 4 gene. The complete mouse laminin alpha 4 cDNA sequence is reported and compared with other laminin alpha chains. In situ hybridization of embryonic and new born mouse tissues revealed expression of laminin alpha 4 mRNA in a subset of endothelium, in particular aortic endothelium, endocardium and endothelium of blood vessels in the skin and in the brain. Strong laminin alpha 4 expression by aortic endothelia was confirmed by data obtained from cultured bovine aortic endothelial cells (BAEC). Isolation of laminin from BAEC conditioned medium revealed a Y-shaped molecule in rotary shadowing. Subsequent sequencing of BAEC laminin resulted in laminin alpha 4, beta 1 and gamma 1 amino acid sequences, confirming that laminin alpha 4 is one of the major laminin alpha chains expressed by aortic endothelium not only in the mouse. In addition, strong laminin alpha 4 mRNA expression occurred in peripheral nerves, cardiac muscle, fat, the dermis of the skin and lung stroma of mouse tissues. The data demonstrate a cytokine and progesterone-regulated differential expression of laminin alpha 4 mRNA in mouse endothelium, suggesting a distinct functional role for this laminin chain in endothelium.
authors.affiliation: Institute for Experimental Medicine, University of Erlangen-Nürnburg, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Frieser
authors.forename: H
authors.initials: H
authors.lastname: Nöckel
authors.forename: F
authors.initials: F
authors.lastname: Pausch
authors.forename: C
authors.initials: C
authors.lastname: Röder
authors.forename: A
authors.initials: A
authors.lastname: Hahn
authors.forename: R
authors.initials: R
authors.lastname: Deutzmann
authors.forename: L M
authors.initials: LM
authors.lastname: Sorokin
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D002417:Cattle; D003001:Cloning, Molecular; D016207:Cytokines / Q000494:pharmacology; D018076:DNA, Complementary / Q000378:metabolism; D004730:Endothelium, Vascular / Q000378:metabolism*; D015870:Gene Expression / Q000187:drug effects; D017403:In Situ Hybridization; D007797:Laminin / Q000235:genetics*; D051379:Mice; D008969:Molecular Sequence Data; D011374:Progesterone / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism
chemical_list: D016207:Cytokines; D018076:DNA, Complementary; C501370:Lama4 protein, mouse; D007797:Laminin; D012333:RNA, Messenger; D011374:Progesterone