Tissue distribution of the laminin β1 and β2 chain during embryonic and fetal human development

Laminins are the major glycoproteins present in all basement membranes. Previously, we showed that perlecan is present during human development. Although an overview of mRNA-expression of the laminin beta 1 and beta 2 chains in various developing fetal organs is already available, a systematic localization of the laminin beta 1 and beta 2 chains on the protein level during embryonic and fetal human development is missing. Therefore, we studied the immunohistochemical expression and tissue distribution of the laminin beta 1 and beta 2 chains in various developing embryonic and fetal human organs between gestational weeks 8 and 12. The laminin beta 1 chain was ubiquitously expressed in the basement membrane zones of the brain, ganglia, blood vessels, liver, kidney, skin, pancreas, intestine, heart and skeletal system. Furthermore, the laminin beta 2 chain was present in the basement membrane zones of the brain, ganglia, skin, heart and skeletal system. The findings of this study support and expand upon the theory that these two laminin chains are important during human development.