Leukemia inhibitory factor null mice: Unhampered in vitro outgrowth of sensory axons but reduced stimulatory potential by nerve segments

Leukemia inhibitory factor (LIF) is locally up-regulated after peripheral nerve injury and may be involved in the subsequent regeneration. Here, adult mice with or without LIF gene deletions were used to study the role of LIF in regeneration. The results show that axonal regeneration in vitro from dorsal root ganglia (DRGs) was unaffected by LIF deletion. However, segments from wild type mice promoted DRG axonal outgrowth better than segments from LIF deleted animals when in vivo-injured sciatic nerve segments were co-cultured with DRGs from normal adult mice. Addition of LIF could not restore the deficit. This suggests that LIF is engaged in the local regulation of regeneration but not in the regenerative events occuring at the cell body level. (C) 2000 Elsevier Science Ireland Ltd.