Differentiation, extracellular matrix synthesis, and integrin assembly by Drosophila embryo cells cultured on vitronectin and laminin substrates

Abstract

ABSTRACTwas unnecessary for myotube formation on laminin, it was required for the subsequent change to a sarcomeric cytoarchitecture. The differentiating primary cultures synthesized integrins and assembled them into detergent-insoluble, cytoskeleton-associated complexes. Collagen IV, laminin, glutactin, papilin, and other extracellular matrix proteins were made primarily by hemocytes and were secreted into the medium. Further differentiation within the cultures was influenced by secreted components and by later addition of vitronectin or bovine serum. Comparison of the differentiation of various cell types on the two substrates showed that vitronectin provided a selective advantage for the differentiation of myocytes, with enrichment over epithelia, epidermal cells, and neurites. 0 1994 Wiley-Liss, Inc.

Vitronectin is not essential for normal mammalian development and fertility.

“…In contrast to our observation with VN, targeted disruption of the FN gene results in a profound disturbance in embryogenesis (16). Other proteins such as osteopontin (32), collagen, or laminin may also partially overlap VN function, with the latter shown to substitute for VN in supporting Drosophila myocyte differentiation in vitro (10). Similar overlapping function has been observed in other systems where double deficiency for two regulatory factors may unmask critical effects not evident from deletion of either component alone (33).…”

“…VN has been thought to serve as a scaffold for the adhesion and migration of embryonic avian endocardial cells (7) and for neural crest cells (8). VN has also been shown to induce neurite outgrowth from PC12 cells (9) and to promote myocyte differentiation in the Drosophila embryo (10).…”

Macrophage-mediated corpse engulfment is required for normalDrosophilaCNS morphogenesis

“…Drosophila macrophages produce extracellular matrix components such as collagen IV, laminin, papilin, glutactin and macrophage-derived proteoglycan-1 (MDP-1) Gullberg et al, 1994;Hortsch et al, 1998), and the presence of cell corpses is known to enhance production of at least one of these, MDP-1 (Hortsch et al, 1998). That Pvr, serpent neo45 and crq RNAi animals all show a mild elongation of the nerve cord (H.C.S., C.J.K.…”

Vitronectin Expression and Interaction With Receptors in Smooth Muscle Cells From Human Atheromatous Plaque

“…[10][11][12] VN has also been shown to induce neurite outgrowth and differentiation 13 and to promote myocyte differentiation in Drosophilia embryos. 14 In addition, VN may interact with several critical coagulation and fibrinolysis proteins. VN binds and stabilizes PAI-1 in its active conformation 15,16 and binds to u-PA receptor, 17 suggesting an additional role for VN in the control of protease activity.…”