Expression of mRNAs for ciliary neurotrophic factor (CNTF), leukemia inhibitory factor (LIF), interleukin-6 (IL-6), and their receptors (CNTFR alpha,LIFR beta, IL-6R alpha, and gp130) in human peripheral neuropathies

The mRNA levels of neuropoietic cytokines, ciliary neurotrophic factor (CNT F), leukemia inhibitory factor (LIF), and interleukin-6 (IL-6), and their r eceptor components (CNTFR alpha, LIFR beta, IL-6R alpha, and gp130) were ex amined in seventy-six patients with various peripheral neuropathies to dete rmine the extent of expression of these cytokines and receptors, and their relationship to nerve fiber pathology and cell infiltration in the diseased nerves. The CNTF mRNA levels were significantly decreased in the diseased nerves and were correlated to residual myelinated fiber population. In cont rast, the mRNA levels of LIF, IL-6 and the ligand-binding receptor componen ts (CNTFR alpha, LIFR beta and IL-6R alpha) were elevated to variable exten t in the diseased nerves. The CNTFR alpha, LIFR beta, and IL-6R alpha mRNA levels showed a weak positive correlation with the extent of demyelinating pathology and their levels were related to each other. Moreover, the CNTF a nd LIF mRNA levels were inversely proportional to the extent of macrophage invasion, whereas the CNTFR alpha and IL-6R alpha mRNA expressions were cor related to the increase in macrophage infiltration. The neuropoietic cytoki ne family and its receptor expressions in the diseased human nerves are reg ulated by an underlying pathology-related process rather than type of disea ses, and could play a role in peripheral nerve regeneration and repair.