Abstract
Neuropeptides FF (NPFF), AF (NPAF), and SF (NPSF) are homologous amidated peptides that were originally identified on the basis of similarity to the molluscan neuropeptide FMRF-amide. They have been hypothesized to have wide-ranging functions in the mammalian central nervous system, including pain modulation, opiate function, cardiovascular regulation, and neuroendocrine function. We have cloned the NPFF gene from human, bovine, rat, and mouse, and show that the precursor mRNA encodes for all three of the biochemically identified peptides (NPFF, NPAF, and NPSF). We demonstrate that NPFF precursor mRNA expression by Northern analysis and map sites of expression by in situ hybridization. We confirm the validity of the in situ hybridization by showing that its distribution in the brain and spinal cord matches the distribution of NPFF and NPSF immunoreactivity. We go on to show that the mRNA levels (as measured by in situ hybridization) in the spinal cord can be up-regulated by a model for inflammatory pain (carrageenan injection), but not by a model for neuropathic pain (lumbar nerve ligation). Our results confirm the evolutionary conservation of NPFF, NPAF, and NPSF neuropeptide expression in mammalian brain. They also provide a context for the interpretation of the pain-sensitizing effects of injections of these peptides that have been previously reported. Our results support a model for the role of these peptides in pain regulation at the level of the spinal cord.
Footnotes
-
Send reprint requests to: Dr. Edward B. Ziff, Howard Hughes Medical Institute, New York University Medical Center, Department of Biochemistry, 550 First Ave., New York, NY. E-mail:edward.ziff{at}med.nyu.edu
-
Supported by Medical Research Council of Finland, Juselius Foundation and Signal Transduction Program of Åbo Akademi University and Howard Hughes Medical Institute (HHMI). F.S.V. was an Associate and E.B.Z. is an Investigator of HHMI. Portions of this work were previously presented in abbreviated fashion in the following abstracts: Vilim FS and Ziff E (1995) Cloning of the neuropeptide NPFF and NPAF precursor from bovine, rat, mouse, and human. Neurosci Abstr21:760; Panula P, Nieminen M, Aarnisalo AA, Lintunen M, Karhunen T, Vilim FS, Ziff E and Karlstedt K (1996) Expression of neuropeptide FF precursor in rat CNS. Soc Neurosci Abstr22:1557; Aarnisalo AA, Nieminen M, Kontinen V, Vilim FS, Kalso E, Ziff E and Panula P (1997) Expression of NPFF mRNA in carrageenan inflammation in the spinal cord. Soc Neurosci Abstr23:1806.
- Abbreviations:
- NPFF
- neuropeptide FF
- NPAF
- neuropeptide AF
- NPSF
- neuropeptide SF
- CNS
- central nervous system
- RACE
- rapid amplification of cDNA ends
- PCR
- polymerase chain reaction
- DTT
- dithiotreitol
- SP
- Substance P
- PAN
- primary afferent nociceptor
- Received July 2, 1998.
- Accepted February 3, 1999.
- The American Society for Pharmacology and Experimental Therapeutics
MolPharm articles become freely available 12 months after publication, and remain freely available for 5 years.Non-open access articles that fall outside this five year window are available only to institutional subscribers and current ASPET members, or through the article purchase feature at the bottom of the page.
|