Transforming growth factor-alpha in the mammalian brain. Immunohistochemical detection in neurons and characterization of its mRNA

• Published in: The Journal of biological chemistry Vol. 264; no. 7; pp. 3880 - 3883
• Main Authors: KUDLOW, J. E, LEUNG, A. W. C, KOBRIN, M. S, PATERSON, A. J, ASA, S. L
• Format: Journal Article
• Language: English
• Published: Bethesda, MD American Society for Biochemistry and Molecular Biology 05.03.1989
• Subjects: Analytical, structural and metabolic biochemistry; Animals; Antibodies, Monoclonal - immunology; Biological and medical sciences; Blotting, Northern; Brain - metabolism; Cattle; Enkephalins - metabolism; Fundamental and applied biological sciences. Psychology; Immunoenzyme Techniques; Neurons - metabolism; Protein hormones. Growth factors. Cytokines; Protein Precursors - metabolism; Proteins; Rats; RNA, Messenger - metabolism; Transforming Growth Factors - metabolism; Human; Immunohistochemistry; Brain; Molecular hybridization; Rat; Transforming growth factor; Rodentia; Monoclonal antibody; Vertebrata; Mammalia; Neuron; Messenger RNA; Radioimmunoassay
• ISSN: 0021-9258; 1083-351X

In this communication, we demonstrate that adult mammalian brain neurons express transforming growth factor-alpha (TGF-alpha). We used the anti-TGF-alpha monoclonal antibody, MF9, to immunohistochemically localize TGF-alpha in human and rat brain. We found specific immunoreactivity in neurons throughout the brain which was not a result of cross-reactivity of MF9 with the neuropeptide, synenkephalin. Northern blot analysis of bovine and rat brain RNA using human and rat TGF-alpha cDNA probes, respectively, revealed a single 4.8-kilobase pair mRNA with approximately equal abundance in the bovine brainstem, cerebellum, hypothalamus, and cerebral cortex. Fetal rat brain had about 2-fold more TGF-alpha mRNA than did adult rat. The brain TGF-alpha cDNA was cloned from a human neonatal brainstem library. Four identical clones were isolated after screening 10(6) recombinant lambda gt11 phage. The sequence of the 894-base pair cDNA was virtually identical with the cDNA isolated from a human renal cell carcinoma. A single alanine codon was deleted in the brain cDNA at an exon-exon junction. The alanine deletion is within the amino-terminal region of the TGF-alpha precursor that is thought to be removed by proteolytic processing of the precursor to the mature growth factor. These studies indicate that the normal mammalian brain neurons express TGF-alpha.