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F J Naves

Publications and source records attributed to F J Naves.

35 records · Page 2Linked to original sources
PubMed1996

Epidermal growth factor receptor in adult human dorsal root ganglia.

Transforming growth factor-alpha (TGFalpha) enhances neuronal survival and neurite outgrowth in cultured dorsal root ganglia (DRG) sensory neurons. It binds a membrane protein, denominated epidermal growth factor receptor (EGFr). EGFr has been localized in developing and adult human DRG. However, it remains to be elucidated whether all DRG neurons express EGFr or whether differences exist among neuronal subtypes. This study was undertaken to investigate these topics in adult human DRG using immunoblotting, and combined immunohistochemistry and image analysis techniques. A mouse monoclonal antibody (clone F4) mapping within the intracytoplasmic domain of EGFr was used. Immunoblotting revealed two main proteins with estimated molecular masses of approximately/equal to 65 kDa and 170 kDa, and thus consistent with the full-length EGFr. Additional protein bands were also encountered. Light immunohistochemistry revealed specific immunoreactivity (IR) for EGFr-like proteins in most (86%) primary sensory neurons, the intensity of immunostaining being stronger in the small- and intermediate-sized ones. Furthermore, EGFr-like IR was also observed in the satellite glial cells of the ganglia as well as in the intraganglionic and dorsal root Schwann cells. Taken together, our findings demonstrate that EGFr, and other related proteins containing the epitope labeled with the antibody F4, are responsible for the EGFr IR reported in DRG. Furthermore, we demonstrated heterogeneity in the expression of EGFr-like IR in adult human primary sensory neurons, which suggests different responsiveness to their ligands.

Adult↗
PubMed1996

Distribution of p75 and trk-neurotrophin receptor proteins in adult human sympathetic ganglia.

We investigated the expression of immunoreactivity (IR) for low- (p75) and high-affinity (trk proteins) neurotrophin-receptor proteins in adult human paravertebral-sympathetic ganglion neurons. Mouse monoclonal antibodies against the pan-neurotrophin-receptor p75, and rabbit polyclonal antibodies against specific epitopes of the intracytoplasmic domain on trk neurotrophin-receptor proteins were used in fresh unfixed and formaldehyde-fixed paraffin-embedded sympathetic ganglia. All adult human paravertebral-sympathetic neurons displayed trkA neurotrophin-receptor-like protein IR, 10% express trkC neurotrophin-receptor-like protein IR, 37-44% show p75 IR, and no IR was obtained for trkB neurotrophin-receptor-like protein. The intensity of immunostaining was independent of the neuron size. Labelling of non-neuronal tissues, especially blood-vessel walls, was observed for p75, trkA and trkC neurotrophin-receptor proteins. These results indicate that overlapping exists in the expression of p75 and trk neurotrophin-receptor proteins in adult human paravertebral-sympathetic neurons, and suggest that neurotrophins might act on these neurons.

Adult↗
PubMed1995

Beta-amyloid precursor protein in human digital skin.

The occurrence and distribution of beta-amyloid precursor protein (beta APP) and of beta-amyloid peptide (beta/A4) was investigated using immunoblotting and immunohistochemical techniques in the digital skin of healthy adult subjects. beta APP-like proteic bands with apparent molecular masses between 55-60 kDa, 100-125 kDa (corresponding to the full-length beta APP isoforms), 145-150 kDa, and 200 kDa were found in pellets and supernatants of whole skin and dermis. The same proteins, except that of approximately 200 kDa, were also found in pellets from the epidermis, whereas epidermic supernatants were unreactive. beta/A4 was not found by immunoblotting. Light microscope immunohistochemistry showed beta APP immunoreactivity (IR) in: (a) dermal nerves; (b) lamellar cells of Meissner, as well as inner-core, outer-core and capsule of Pacinian corpuscles; and (c) dermal blood vessels, sweat glands and, occasionally, epidermis. The distribution of beta/A4 IR matched that of beta APP, and no evidence of extracellular beta/A4 IR was encountered. Present results demonstrate that beta APP, but not beta/A4, is normally present in human glabrous (digital) skin. The potential clinical relevance of these findings is discussed.

Adult↗
PubMed1995

Effect of treatment with the dihydropyridine-type calcium antagonist darodipine (PY 108-068) on the expression of calbindin D-28K immunoreactivity in the cerebellar cortex of aged rats.

The influence of long term treatment with the dihydropyridine-type Ca2+ antagonist darodipine (PY 108-068) on age-dependent changes in calbindin D-28K immunoreactivity in the cerebellar cortex of male Wistar rats was assessed. In 12-month-old rats used as an adult reference group, specific calbindin D-28K immunoreactivity was found within the cytoplasm of Purkinje neurons and their dendritic processes. The number of Purkinje neurons displaying calbindin D-28K immunoreactivity was decreased in the cerebellar cortex of aged in comparison with adult rats. The pattern of calbindin D-28K immunoreactivity was similar in the cerebellar cortex of 24-month-old rats (aged), although a significant decrease in the intensity of immunoreactivity was noticeable. Treatment of aged rats with darodipine for 6 months increased the percentage of immunoreactive Purkinje neurons and the intensity of calbindin D-28K immunoreactivity in the cytoplasm of Purkinje neurons. Calbindin D-28K is a Ca2+ binding protein probably involved in the modulation of Ca2+ homeostasis. The observation of a positive effect of darodipine treatment on calbindin D-28K immunoreactivity in the cerebellar cortex suggests that manipulation of dihydropyridine-type Ca2+ channels may contribute to counter age-dependent changes of Ca2+ homeostasis.

Aging↗
PubMed1995

Immunohistochemical localization of laminin and type IV collagen in human cutaneous sensory nerve formations.

We used immunohistochemical techniques and monoclonal antibodies to localize two basement membrane components (laminin and type IV collagen) in the nerves and sensory nerve formations, or corpuscles, supplying human digital skin. Furthermore, neurofilament proteins, S-100 protein and epithelial membrane antigen were studied in parallel. In dermal nerve trunks, immunostaining for laminin and type IV collagen was found to be co-localized in the perineurium and the Schwann cells, the stronger immunoreactivity being at the external surface of the cells. In the Meissner digital corpuscles, the immunoreactivity for laminin and type IV collagen was mainly observed underlying the cell surface of lamellar cells, while the cytoplasm was weakly immunolabelled or unlabelled. Finally, within Pacinian corpuscles co-localization of the two basement membrane molecules was encountered in the inner core, intermediate layer, outer core and capsule. Laminin and type IV collagen immunoreactivities were also found in blood vessels and sweat glands, apparently labelling basement membrane structures. The present results provide evidence for the presence of basement membrane in all periaxonic cells forming human cutaneous sensory nerve formations, and suggest that all of them are able to synthesize and release some basement membrane components, such as laminin and type IV collagen. The possible role of laminin in sensory nerve formations is discussed.

Adolescent↗
PubMed1995

Age-related changes in brain microanatomy: sensitivity to treatment with the dihydropyridine calcium channel blocker darodipine (PY 108-068).

The influence of aging and of treatment with the dihydropyridine Ca2+ antagonist darodipine (PY 108-068) on the age-related microanatomical changes of rat brain were studied in male Wistar rats treated from the 18th to the 24th month of age with an oral dose of 5 mg/kg/day of darodipine. Twelve-month-old untreated rats were used as an adult reference group. A decreased number of nerve cells and of alkaline phosphatase-positive capillaries and an increased lipofuscin deposition were observed in the frontal and occipital cortex, in the hippocampus, and in the cerebellar cortex of rats of 24 months in comparison with 12-month-old animals. The number of nerve cells was higher in the occipital cortex and in the hippocampus, but not in the frontal cortex and in the cerebellar cortex, of darodipine-treated rats in comparison with age-matched untreated animals. Lipofuscin deposition is reduced in all the brain areas investigated. The density of alkaline phosphatase-reactive capillaries is also increased in the frontal and occipital cortex and in the hippocampus of aged rats treated with darodipine. The above results suggest that treatment with darodipine is able to counter some microanatomical changes occurring in the brain of aged rats and involving not only microvascular parameters. The occipital (visual) cortex and the hippocampus were the cerebral areas more sensitive to treatment with darodipine. The possible relevance of these findings is discussed.

Aging↗
PubMed1995

beta-Amyloid precursor protein (beta APP) in human gut with special reference to the enteric nervous system.

The distribution of the beta-amyloid precursor protein (betaAPP) in the human gastrointestinal tract, from esophagus trough rectum, was studied using immunoblotting, as well as combined immunohistochemical and image analysis (optic microdensitometry) techniques. The study was focused on the enteric nervous system. betaAPP was detected by means of a monoclonal antibody (22C11), which recognizes all betaAPP isoforms as well as betaAPP-like proteins. Immunoblotting revealed two main protein bands, one corresponding to full-length betaAPPs (estimated molecular masses of approximately 97-115 kDa); the other corresponded to a protein with estimated molecular masses of 55 kDa. Specific betaAPP immunoreactivity (IR) was found in the submucous and myenteric plexuses localized in the supporting glial cells rather than in neurons. Differences were encountered neither in the localization nor in the intensity of immunostaining among different segments of the gastrointestinal tract. Moreover, no age-dependent changes were found. betaAPP IR was also regularly observed in blood vessels, primarily labelling endothelial cells. Our results provide evidence for the occurrence of betaAPP in human gastrointestinal tract of healthy people in both neuronal and nonneuronal tissues. Whether or not these findings have functional or clinical relevance remains to be clarified in future studies.

Adult↗
PubMed1995

Neurotrophin receptor proteins immunoreactivity in human gastrointestinal endocrine cells.

The distribution of neurotrophin receptors (p75, trkA-, trkB-, and trkC-receptor proteins) was studied by immunohistochemistry on sections of human gastrointestinal tract mucosa from esophagus through rectum. Moreover, chromogranin A (CgA) was studied in parallel to identify endocrine cells (EC). In all of the analyzed samples there was specific immunoreactivity (IR) for trkB-receptor protein in EC, the percentage of which varied between 26 +/- 0.6% for the duodenum and 78 +/- 3% for the sigmoid colon. EC displaying trkC-receptor protein IR were also encountered, in some cases, in EC of the gastric fundus (9%), duodenum (12%), jejune (23%), and colon (12%); trkA-receptor protein IR was occasionally present labelling EC in the jejune (52%), ileum (25%), and sigmoid colon (18%); finally, p75 was in 21% of EC exclusively in one case in the ileum. In addition to EC, IR for all assessed antigens was also present in the submucous blood vessels. Our results provide evidence for the occurrence of neurotrophin receptor proteins in nonneuronal tissues and suggest that neurotrophins, especially that binding trkB receptor proteins, can regulate a subpopulation of EC cells. However, whether EC expressing different trk receptor proteins represent neurochemical subtypes of EC, and whether the identified trk receptor proteins correspond to functional receptors, remain to be elucidated.

Adult↗
PubMed1995

Immunohistochemical characteristics of cutaneous Herbst corpuscles from beak and rictus in domestic pigeon.

Herbst corpuscles are the avian equivalent to the mammalian Pacinian corpuscles. In this study we used indirect peroxidase-anti peroxidase (PAP) immunohistochemistry to analyze the distribution in the pigeon cutaneous Herbst corpuscles, of several markers which are known to specifically label the axon, the Schwann-related and perineurial-related cells in Pacinian corpuscles. The distribution of the assessed antigens on Herbst corpuscles was as follows: i) the central axon displayed positive immunoreactivity for neurofilament proteins and neuron specific enolase; ii) the lamellar cells forming the inner-core were positive for S-100 protein and vimentin, whereas fibroblast surrounding them were vimentin and epithelial membrane antigen positive; iii) the capsule was focally immunolabelled for vimentin, and regularly for epithelial membrane antigen. No immunoreactivity was found neither for cytokeratins nor for glial fibrillary acidic protein. These observations demonstrate that the immunohistochemical profile of cutaneous (beak skin and rictus) Herbst corpuscles in pigeon is similar to that of the mammalian Pacinian corpuscles.

Animals↗
PubMed1994

Expression of beta-amyloid precursor protein (APP) in human dorsal root ganglia.

The present study reports the occurrence and localization of beta-amyloid precursor protein (APP) immunoreactivity (IR) in human lumbar dorsal root ganglia of healthy adult subjects (age range 25-43 years). To ascertain that ganglionic cells displayed APP IR, neurofilament (NFP) and S-100 proteins (S100P) were studied in parallel. Immunoblotting revealed four or five major proteins with apparent molecular masses between 100-125 kDa, which corresponded with the different full-length APP isoforms. Moreover, an additional protein of approximately 55 kDa was detected. Selective APP IR was observed restricted to the satellite glial cell cytoplasms whereas neuron cell bodies resulted unlabeled. Moreover, some intraganglionic nerve fibers also displayed APP IR, apparently labelling Schwann cells. No individual differences among subjects were observed neither in the pattern of APP IR distribution, nor in the intensity of APP IR. Although it remains to be demonstrated whether or not human primary sensory neurons express APP, present results strongly suggest that supporting glial cells may be a primary source of APP or any related peptide, at least in adult healthy people. The functional and clinical relevance of these findings, if any, remain to be clarified.

Adult↗
PubMed1994

beta-Amyloid precursor protein (APP)-like immunoreactivity in the human sympathetic ganglia.

The localization of the beta/A4 amyloid precursor protein (APP) was studied in the human lumbar paravertebral sympathetic ganglia of subjects of different ages, free of neurologic disease, using combined immunohistochemistry and image analysis techniques (optic microdensitometry). To ascertain which cells displayed APP-like immunoreactivity (APP-LI), S-100 and neurofilament proteins were studied in parallel to label the supporting glial cells and the neuron perikarya, respectively. Specific APP-LI was observed labelling both neuron cell bodies and supporting glial cells independently of age. In all cases, the intensity of immunostaining was stronger in glial cells than in neurons. Moreover, the intensity of APP-LI was independent of both age and neuron size. Present results provide evidence for the presence of APP-LI in the human sympathetic ganglia, and for the absence of changes in the expression of this protein, or proteins, with aging. The functional and clinical relevance of these findings remains to be clarified.

Adult↗
PubMed1994

Expression of epidermal growth factor receptor (EGFr) immunoreactivity in human cutaneous nerves and sensory corpuscles.

BACKGROUND: The epidermal growth factor receptor (EGFr) binds both epidermal growth factor (EGF) and transforming growth factor alpha (TGF alpha), which are currently considered among putative growth factors playing a role in the nervous system. EGFr and their ligands have been localized in the mammalian peripheral nervous system. The present study was undertaken to investigate whether nerves and sensory corpuscles supplying human glabrous skin express EGFr. METHODS: Formaldehyde fixed, paraffin embedded samples of finger-tip digital skin obtained from adult healthy subjects were processed for indirect PAP immunohistochemistry using a monoclonal antibody against an epitope of the intracellular domain of EGFr. To ascertain the localization of EGFr immunoreactivity, neurofilament proteins (NFP), S100 protein (S100P), and epithelial membrane antigen (EMA) were studied in parallel to label axons, Schwann cells, and perineurial cells, respectively, as well as their corpuscular derivatives. RESULTS: A variable intensity of EGFr immunostaining was regularly observed in the perineurium and Schwann cells, and occasionally in the axons of nerve bundles. EGFr immunoreactivity was also present in the axon and lamellar cells of Meissner corpuscles, and within the axon, inner-core, outer-core, and capsule of Pacinian corpuscles. CONCLUSIONS: Present results demonstrate that human cutaneous nerves and sensory corpuscles express EGFr suggesting a role for peptides able to bind EGFr, i.e., EGF and TGF alpha, in the human peripheral nervous sensory system.

Adult↗
PubMed1994

Immunohistochemical localization of the high-affinity NGF receptor (gp140-trkA) in the adult human dorsal root and sympathetic ganglia and in the nerves and sensory corpuscles supplying digital skin.

BACKGROUND: Nerve growth factor (NGF) is produced in target tissues of sympathetic and neural-crest derived sensory neurons, including skin, to provide them trophic support. The biological effects of NGF on responsive cells are mediated by specific high-affinity receptors. Recently, a protein tyrosine kinase of congruent to 140 kDa molecular weight, encoded by the proto-oncogene trkA, has been identified as the high-affinity NGF receptor (gp140-trkA). The present work was undertaken to study the localization of gp140-trkA-like immunoreactivity (IR) in human peripheral ganglia (sympathetic and dorsal root ganglia), and in glabrous skin. METHODS: Lumbar dorsal root ganglia, para- and prevertebral sympathetic ganglia, and digital glabrous skin were studied immunohistochemically using a rabbit anti-gp140-trkA polyclonal antibody. In order to accurately establish the localization of gp140-trkA IR, the neurofilament proteins and S-100 protein were studied in parallel in: (1) sensory and sympathetic ganglia, to label neuron cell bodies and satellite or supporting cells, respectively; (2) human skin, to label axons, Schwann and related cells within nerves and sensory corpuscles. Moreover, a quantitative study (neuron size, intensity of immunostaining) was carried out on sympathetic and dorsal root ganglia neuron cell bodies. RESULTS: A specific gp140-trkA-like IR was found in: (1) a subpopulation (65%) of primary sensory neuron cell bodies, including most of the large-sized ones but also small- and intermediate-sized ones; (2) most of sympathetic neuron cell bodies (82%); (3) the perineurial cell, Schwann cells, and large axons of the nerve trunks supplying digital skin; (4) the lamellar cells of Meissner corpuscles; (5) the central axon, inner-core, outer-core, and capsule of Pacinian corpuscles. In addition, the occurrence of gp140-trkA-like IR was observed in some non-nervous tissues of the skin, including epidermis (mainly in the basal layer), sweat glands, and arterial blood vessels. CONCLUSIONS: Present results provide evidence for the localization of gp140-trkA-like IR in: (1) nerve cells which are known to be NGF-responsive, and (2) non-nervous cutaneous tissues which are innervated by NGF-dependent peripheral neurons. These findings suggest that, in addition to the well-established role of NGF on sensory and sympathetic neurons, this neurotrophin may be able to regulate some other functions on non-nervous cells which are targets for NGF-dependent peripheral neurons.

Adult↗
PubMed1994

Immunoreactivity for phosphorylated 200-kDa neurofilament subunit is heterogeneously expressed in human sympathetic and primary sensory neurons.

This study was undertaken to investigate whether human sensory and sympathetic neurons contain phosphorylated neurofilament proteins, and whether they may be classified on the basis of this property, as in other mammalian species. The distribution of the phosphorylated 200-kDa neurofilament protein subunit (p200-NFP) was investigated in lumbar sympathetic and dorsal root ganglia by means of the RT97 monoclonal antibody (against p200-NFP). The intensity of immunostaining, and the size of neuronal body profiles were measured in order to define different neuron subclasses. In dorsal root ganglia, most of the neuronal profiles (96%) were p200-NFP immunoreactive, and the intensity of immunostaining was not related to neuronal perikarya size. In the lumbar paravertebral sympathetic ganglia, virtually all neurons displayed p200-NFP immunoreactivity, and the intensity of immunolabelling was also independent of the size of the neuronal somata. These results demonstrate heterogeneity in the expression of p200-NFP immunoreactivity in human sympathetic and sensory neurons. In contrast to other mammalian species, RT97 immunolabelling cannot be used as a discriminative marker for the two main types of human primary sensory neurons. On the other hand, our findings provide evidence for the occurrence of phosphorylated neurofilaments within peripheral neuron cell bodies.

Adult↗
PubMed1994

Distribution of protein gene product 9.5 (PGP 9.5) immunoreactivity in the dorsal root ganglia of adult rat.

The rat dorsal root ganglia (DRG) contain heterogeneous subpopulations of sensory neurons as demonstrated by ultrastructural, histochemical and immunohistochemical methods. In this study we investigated whether phenotypic heterogeneity occurs in the distribution of protein gene product 9.5 (PGP 9.5) in DRG neurons of adult rats by combined immunohistochemical and image analysis (neuron-size and intensity of immunostaining) techniques. Moreover, the effect of different fixatives on the expression of PGP 9.5 was analyzed. PGP 9.5 immunoreactivity (IR) was observed in all primary sensory neurons and in the axons of the ganglionic nerve fibres, but not in the satellite glial cells or Schwann cells. Data from a quantitative study demonstrated that DRG neurons displayed a homogeneous pattern of PGP 9.5 IR which was not affected by fixatives, and no correlation between neuron size and intensity of immunostaining was encountered. Thus, as reported for other neuronal and neuroendocrine cell proteins, no heterogeneity exists in the phenotypic expression of immunohistochemically demonstrable PGP 9.5 in sensory neurons of the adult rat DRG.

Animals↗
PubMed1994

The inner-core, outer-core and capsule cells of the human Pacinian corpuscles: an immunohistochemical study.

The distribution of several markers for Schwann cells and perineurial cells, including S-100 protein, Leu-7 antigen, vimentin and epithelial membrane antigen was studied immunohistochemically in Pacinian corpuscles from human digital skin. Formaldehyde fixed paraffin embedded tissues, and monoclonal antibodies were used. A positive immunostaining for S-100 protein, Leu-7 antigen and vimentin was found in the inner-core cells, whereas the outer-core and capsule lamellae were labelled for both epithelial membrane antigen and vimentin. The pattern of vimentin immunoreactivity was not homogeneous but focally distributed, and occasionally, positive immunoreactivity for vimentin was observed in blood vessels supplying the capsule. Present results provide evidence that some antibodies against Schwann cells and perineurial fibroblastic cells, selectively stain the Pacinian corpuscles derivatives while others are commonly expressed for non-neuronal cells of sensory nerve corpuscles.

Adolescent↗