Nerve growth factor, laminin, and fibronectin promote neurite growth in human fetal sensory ganglia cultures

Abstract

The effect of mouse nerve growth factor (NGF) on cultured human fetal sensory neurons was assayed by measuring neurite length, density and rate of growth. Addition of NGF increased adhesion of dissociated sensory neurons cultured on collagen coated surfaces. Almost all neurons of 9 to 10 week old fetuses are postmitotic, contain neuron-specific enolase, (an enzyme linked to differentiation), and require NGF for optimal neurite growth. Sensory ganglia re-explanted on collagen showed maximal neurite length and density when treated with 1 ng/ml of NGF. Neurite density was reduced considerably in the absence of mouse NGF and was almost abolished by addition of antimouse NGF antibodies. Surfaces coated with the matrix glycoproteins laminin or fibronectin further stimulated neurite growth of ganglia in the presence of NGF. Increasing amounts of matrix proteins could partly compensate for the absence of mouse NGF or the inhibition of NGF activity by antibodies. Stimulation of neurite growth by matrix proteins was time-dependent, and neurites showed maximum length at 10 days (2 to 3 mm). Neurite growth was more pronounced with laminin than with fibronectin and collagen, and antibodies to laminin suppressed all neurite growth. In the presence of a constant amount of NGF, mean neurite growth reached 26 microns/hr (at 1 day), and was 2.1 and 1.7 times faster on laminin and fibronectin (respectively) than on collagen. Thus, laminin, and to a lesser degree fibronectin, may enhance neurite growth of human sensory neurons in synergy with NGF.

Specific Induction of Cell Motility on Laminin by α7 Integrin

“…Laminin has the ability to induce outgrowth of neurites (32,33) and of filopodia and lamellopodia, e.g. in Schwann cells (34) or myoblasts (18).…”

Differences between the effect of anisotropic and isotropic laminin and nerve growth factor presenting scaffolds on nerve regeneration across long peripheral nerve gaps

“…Scaffolds with gradient of either LN-1 or NGF, with the other component at uniform distribution, did not promote axonal regeneration across the challenging 20 mm nerve gap. LN-1 is an appropriate candidate as the protein of choice to promote PNS regeneration since it has been shown to be a potent stimulator of neurite outgrowth [21,27,50]. In most neuronal tissues, development of the axons and formation of new synapses is preceded by migration of the neuronal cell bodies to the appropriate regions of the brain.…”

“…NGF has been shown to stimulate neurite outgrowth and promote the survival of sensory ganglia, including those which give rise to spinal sensory nerves and sciatic nerves [23][24][25]. Due to their potent functions, LN-1 (an isoform of LN) and NGF have been used successfully for neurite extension in vitro and for nerve regeneration in vivo [26][27][28][29][30]. Hence, in this study we have used LN-1 and NGF to promote sciatic nerve regeneration across a 20 mm nerve gap in rats.…”

A monoclonal antibody that blocks the activity of a neurite regeneration-promoting factor: studies on the binding site and its localization in vivo.

“…Experiments in culture, however, have delineated a number of candidate molecules that can promote neurite outgrowth under specific conditions. For instance, surfaces coated with laminin or fibronectin stimulate a much more rapid and extensive regeneration of neuronal processes than can serum-or collagen-coated plastic (2,4,9,24,29,31,39,44). The finding that laminin, in particular, provides an especially good substrate for outgrowth is of interest because a variety of non-neuronal cells secrete neurite regeneration-promoting factors (1,12,14,26), some of which are extracellular matrix complexes containing primarily laminin and heparan sulfate proteoglycan (HeSPG) (8,16,28).…”