Expression of latent transforming growth factor beta binding proteins in the rat brain.
Transforming growth factor-betas are expressed in the brain, have neuroprotective functions, and may be involved in the pathogenesis of neurodegenerative disorders. Their intracellular processing, secretion, and extracellular activation requires latent transforming growth factor-beta binding proteins (LTBPs) as demonstrated in peripheral organs. Here, we first report that the four types of LTBPs are expressed in the rat brain based on reverse-transcriptase polymerase chain reaction (RT-PCR) and that the subtypes have different topographical distributions based on in situ hybridization histochemistry. LTBP-1 has a high expression level in several brain regions including choroid plexus, cerebral cortex, medial amygdaloid nucleus, anteromedial and midline thalamic nuclei, medial preoptic area, arcuate and dorsomedial hypothalamic nuclei, superior olive, and area postrema. LTBP-3 and -4 are the most widely distributed LTBPs. Both are abundant in the cerebral cortex, cerebellum, hypothalamus, amygdala, brainstem motor nuclei, and area postrema. In addition, LTBP-3 mRNA is also abundant in the choroid plexus, globus pallidus, anterior and reticular thalamic nuclei, mamillary body, substantia nigra, red nucleus, pontine nuclei, some brainstem sensory nuclei, and reticular formation, while LTBP-4 is more abundant in the hippocampus and the parabrachial nuclei. In contrast, the expression of LTBP-2 is restricted to cerebral cortex, CA1 neurons of the hippocampus, and perifornical/lateral hypothalamic areas. The hypothalamic cells were identified by double in situ hybridization histochemistry as orexin-synthesizing neurons, demonstrating that LTBP expression can be very specifically regulated. Our data demonstrate that each type of LTBPs have highly distinct distributional patterns suggesting that the expression of LTBPs are specifically regulated in the brain.
Dobolyi
Arpád
A
Neuromorphological and Neuroendocrine Research Laboratory, Department of Anatomy, Histology and Embryology, Semmelweis University and the Hungarian Academy of Sciences, Budapest, H-1094, Hungary. dobolyi@ana.sote.hu
Palkovits
Miklós
M
D000367:Age Factors; D000818:Animals; D001921:Brain / Q000166:cytology / Q000502:physiology*; D015870:Gene Expression / Q000502:physiology; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism; D053779:Latent TGF-beta Binding Proteins / Q000235:genetics*; D008297:Male; D009457:Neuroglia / Q000502:physiology; D009474:Neurons / Q000502:physiology; D009479:Neuropeptides / Q000378:metabolism; D000068797:Orexins; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar / Q000502:physiology*; D020133:Reverse Transcriptase Polymerase Chain Reaction
D047908:Intracellular Signaling Peptides and Proteins; C527902:LTBP3 protein, rat; C527903:LTBP4 protein, rat; D053779:Latent TGF-beta Binding Proteins; C509034:Ltbp1 protein, rat; C509037:Ltbp2 protein, rat; D009479:Neuropeptides; D000068797:Orexins; D012333:RNA, Messenger