A possible role of BDNF in prostate cancer detection.

Many studies have demonstrated that both normal and malignant prostate cells respond to a variety of growth factors, while several significant differences were found between normal and tumoural cells. The aim of this study was to focus on the localization and distribution of the immuno-reactivity for neurotrophins (NTs) and neurotrophin receptors (NTRs) in normal, hyperplastic and prostate cancer cells, obtained from 40 subjects. We studied samples obtained from 16 prostate cancer (PC, retropubic radical prostatectomy), 20 benign prostatic hyperplasia (BPH, supra-pubic prostatectomy) and normal peripheral prostate tissue from four fresh male cadavers. Samples were examined via immunohistochemical techniques in order to detect the expression of nerve growth factor (NGF), brain derived neurotrophic factor (BDNF), neurotrophin 3 (NT3) and their own receptors TrkA, p75, TrkB and TrkC. We observed a high expression of BDNF and TrkB in PC and BPH, though no immuno-reactivity was found for p75. Low expression was reported by other NTs and NTRs in the normal peripheral prostate zone, BPH and PC. These data suggest a possible predictive role for NTs and NTRs, especially for BDNF and TrkB, in the diagnosis and/or management of prostate cancer. The absence of p75 expression confirms its supposed role in apoptotic phenomenon.

Expression of neurotransmitters and neurotrophins in neurogenic inflammation of the rat retina.

Antidromic stimulation of the rat trigeminal ganglion triggers the release of substance P (SP) and calcitonin gene-related peptide (CGRP) from sensory nerve terminals of the capsaicin sensitive C-fibers. These pro-inflammatory neuropeptides produce a marked hyperemia in the anterior segment of the eye, accompanied by increased intraocular pressure, breakdown of the blood-aqueous barrier and myosis. To assess the effects of neurogenic inflammation on the retina, specifically on the immunostaining of neurotransmitters and neurotrophins, as well as on the expression of neurotrophin receptors in the retina. RT-PCR was also accomplished in control and stimulated animals to confirm the immunohistochemical results. In the electrically stimulated eyes, immunostaining for SP, CGRP, VIP and nNOS demonstrated a marked increase in the RPE/POS (Retinal Pigment Epithelium/Photoreceptor Outer Segments), in the inner and outer granular layers and in the ganglion cells in comparison to the control eyes. CGRP and SP were found increased in stimulated animals and this result has been confirmed by RT- PCR. Changes in neurotrophin immunostaining and in receptor expression were also observed after electric stimulation of trigeminal ganglia. Decrease of BDNF and NT4 in the outer and inner layers and in ganglion cells was particularly marked. In stimulated rat retinas immunostaining and RT-PCR showed a NGF expression increase. Neurotrophin receptors remained substantially unchanged. These studies demonstrated, for the first time, that antidromic stimulation of the trigeminal ganglion and subsequent neurogenic inflammation affect immunostaining of retinal cell neurotransmitter/neuropeptides and neurotrophins as well as the expression of neurotrophin receptors.

Immunohistochemical profile of some neurotransmitters and neurotrophins in the seminiferous tubules of rats treated by lonidamine.

Lonidamine (LND) or [1-(2,4-dichlorobenzyl)-1H-indazole-3-carboxylic acid] is an anticancer and antispermatogenic drug that exerts a large number of effects on tumor cells and germ cells. Sexually mature male Sprague-Dawley rats were housed at 22 degrees C on a 12-h light/12-h dark cycle 1 week before the experiments, with free access to food and water. LND was suspended in 0.5% methylcellulose at a concentration of 10 mg/mL and administered orally at the dose of 10 mL/kg (b.w.) as a single dose. Control rats received an equal amount of vehicle. Testes were removed, fixed for 24 h in 2% glutaraldehyde and 2% paraformaldehyde in 0.1 M sodium phosphate (pH 7.2 at 22 degrees C), rinsed with the same buffer, and stored at room temperature. From each sample, a block of tissue was removed by sectioning through the organ. After dehydration in ethanol at increasing concentrations (70-100%), each block was embedded in paraffin and serial 5 mm thick sections were cut using a rotatory microtome. The immunoreactivity for NTs has been observed in spermatogonia of untreated rats, while the rats treated with LND showed an immunohistochemical localization in all the stages of germinal cells. The generally well-expressed immunoreactivity for the neurotrophins receptors in treated rats observed in our study is presumably attributable to alterations of the receptors' structure and/or expression leading to changes of the activity, affinity, localization or protein interactions that may depend on sensitization of ion channels (induced by LND). Neurotrophins (NTs) appear to be interesting proteins for the modulation of sperm maturation and motility with a prominent role for the nerve growth factor (NGF), that may exert an autocrine or paracrine role. We therefore investigated the location and distribution of immunoreactivity for some neurotransmitters (SP, VIP, CGRP, nNOS, Chat), neurotrophins (NGF, BDNF, NT-3) and their own receptors (TrKA, TrKB, TrKC, p75) in the seminiferous tubules of male rats treated by LND in the light of the literature on this topic.

Expression of neurotransmitters and neurotrophins in human adenoid tissue.

Mucosae-associated lymphoid tissues are richly innervated and the mucosae contain peptidergic nerve endings associated with different types of cells and macrophages. The lymphatic tissue is known to interact with the nervous system and several organs, implicated in the host response to a wide range of stressors, and is also richly innervated. We focussed our attention on the immune organs with particular regard to the human adenoid lymphatic tissues in order to investigate the neuroimmune links and the possible existence of relationships among different neurotransmitters and lymphocytes, macrophages, epithelial cells and nerve fibers by testing the expression of certain neurotransmitters and neurotrophins (NTs) with their own receptors.