Retinal Pigment Epithelial Cells Synthesize Laminins, Including Laminin 5, and Adhere to Them through a3- and a6-Containing Integrins

The multilayered extracellular matrix underlying the retina is Bruch’s membrane (BM). Here they show that BM contains laminin chains that could form laminin-111, -332, -511, and -521. RPE cells synthesized these laminin chains in vitro, hence, RPE cells may synthesize BM laminins. The RPE cells adhered to the BM component collagen IV, but preferentially adhered to laminins. Of the laminins tested, the RPE cells adhered preferentially to laminin 332. The RPE cells interacted with these laminins via a3 and a6 containing integrins.