Nerve growth factor inhibits sympathetic neurons’ response to an injury cytokine

Nerve growth factor inhibits sympathetic neurons’ response to an injury cytokine

Department of Neurosciences, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106-4975

Communicated by Susan E. Leeman, Boston University School of Medicine, Boston, MA (received for review February 18, 1998)

Abstract

Axonal damage to adult peripheral neurons causes changes in neuronal gene expression. For example, axotomized sympathetic, sensory, and motor neurons begin to express galanin mRNA and protein, and recent evidence suggests that galanin plays a role in peripheral nerve regeneration. Previous studies in sympathetic and sensory neurons have established that galanin expression is triggered by two consequences of nerve transection: the induction of leukemia inhibitory factor (LIF) and the reduction in the availability of the target-derived factor, nerve growth factor. It is shown in the present study that no stimulation of galanin expression occurs following direct application of LIF to intact neurons in the superior cervical sympathetic ganglion. Injection of animals with an antiserum to nerve growth factor concomitant with the application of LIF, on the other hand, does stimulate galanin expression. The data suggest that the response of neurons to an injury factor, LIF, is affected by whether the neurons still receive trophic signals from their targets.

Footnotes

↵ * Present address: Palatin Technologies, 175 May Street, Suite 500, Edison, NJ 08837.
↵ † Present address: Division of Neuroscience, Department of Neurology, Children’s Hospital, Department of Neurobiology, Harvard Medical School, Boston, MA 02115.
↵ ‡ To whom reprint requests should be addressed at: Department of Neurosciences, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106-4975. e-mail: rez{at}po.cwru.edu.
ABBREVIATIONS:

LIF,

leukemia inhibitory factor;

NGF,

nerve growth factor;

αNGF,

antiserum to nerve growth factor;

NSS,

normal sheep serum;

SCG,

superior cervical ganglion;

GAPDH,

glyceraldehyde-3-phosphate dehydrogenase;

CST,

cervical sympathetic trunk;

CSTX,

CST transection