Temporal expression of mRNAs for neuropoietic cytokines, interleukin-11 (IL-11), oncostatin M (OSM), cardiotrophin-1 (CT-1) and their receptors (IL-11R alpha and OSMR beta) in peripheral nerve injury

The mRNA expression pattern of the neuropoietic cytokines, interleukin-11 ( IL-11), oncostatin M (OSM) and cardiotrophin-1 (CT-1), and their receptor c omponents (IL-11R alpha and OSMR beta) was examined in peripheral nerves on two different types of injury, crush and transection. The IL-11 mRNA incre ased after nerve damage and immediately returned to control levels. The OSM mRNA expression increased rapidly after nerve injury and relatively high e xpressions were maintained for at least 14 days. The CT-1 mRNA was not expr essed in any time before and after the injury. Interestingly, IL-11R alpha was expressed in the intact nerve and decreased after injury. The expressio n of OSMR beta increased slightly after the injury. Moreover, temporal mRNA expression pattern of these neuropoietic cytokines and receptors was simil ar between the crushed and transected models. Each neuropoietic cytokine of IL-11, OSM and CT-1 has its own specific temporal mRNA expression pattern, which is also different from those of ciliary neuro-trophic factor (CNTF), leukemia inhibitory factor (LIF) and interleukin-6 (IL-6). These results s uggest that all neuropoietic cytokines have distinctive functions in nerve degeneration and repair process in response to peripheral nerve injury.