Sergio Domenico Gadau

Morphological and functional changes induced by the amino acid analogue 3-nitrotyrosine in mouse neuroblastoma and rat glioma cell lines

The amino acid analogue 3-nitrotyrosine (3-NT) is formed in neural cells as a result of the intense stimulation of NMDA glutamate receptors. 3-NT is involved in the pathology of diverse neurodegenerative disorders. The aim of our work is to investigate the sensitivity of cultured neural and glial cells to 3-NT. We report the morphological changes detected on mouse neuroblastoma (C1300) and rat glioma (C6) cell lines cultured in a medium supplemented with different 3-NT concentrations. Western blot displayed a selective incorporation of 3-NT into a single protein that co-migrated with tubulin. Both cell lines showed morphological changes, nuclear suffering, decreased viability and growth inhibition (starting from 90 and 360 microM for C1300 and C6, respectively). Such effects were dose-dependent, though glioma cells showed severe alterations at higher 3-NT concentrations. Our results point out a higher 3-NT sensitivity in the neural cells studied in comparison with those of glial origin. The dramatic toxicity of 3-NT in neural cells suggests further investigations focused on the biochemical mechanisms at the roots of neurodegenerative diseases.

Ancient Pompeian Dogs – Morphological and Morphometric Evidence for Different Canine Populations

This article examines the morphological features of the dog during the Roman Age on the basis of osseous and dental remains dug up in Pompeii. The material, consisting of 113 canine bones and teeth, was subjected to both morphological and morphometrical analyses and was compared with modern canine breeds. In most cases, the age at death, shoulder height and other phenotypic features were ascertained. The examined Pompeian canine population fell mainly into two categories: small‐ and large‐sized animals. Among the former, one brachycephalic and two dolichocephalic subjects were included. Such morphological features agree with what is described in numerous texts and appears in mosaics, bas‐reliefs and frescoes of the Roman Age. As small‐sized dogs cannot be classified as Canes Venatici (sporting dogs), Canes Villatici (watch dogs) and Canes Pastorales (shepherd dogs) according to Columellas De re rustica, these animals may be considered as lapdogs.

Aromatase immunoreactivity in fetal ovine neuronal cell cultures exposed to oxidative injury

A lot of evidence testifies that aromatase is expressed in the central nervous system where it has been detected not only in hypothalamic and limbic regions but also in the cerebral cortex and spinal cord. In physiological conditions, aromatase is expressed exclusively by neurons, where it has been mainly found in cell bodies, processes and synaptic terminals. Moreover, primary cultured cortical astrocytes from female rats are more resistant to oxidant cell death than those from males, suggesting a protective role of estradiol. The aim of this study was to evaluate changes in aromatase expression in response to 3-nitro-L-tyrosine, a marker of oxidative stress, in primary neuronal cell cultures from brains of 60-day old sheep fetuses. Cells were identified as neurons by using class III β-tubulin, a marker of neuronal cells. Two morphological types were consistently recognizable: i) bipolar cells with an oval cell body; ii) multipolar cells whose processes formed a wide net with those of adjacent cells. In situ hybridization technique performed on 60-day old fetal neurons revealed that in baseline conditions aromatase gene expression occurs. Importantly, cells exposed to 360 µM 3-nitro-L-tyrosine were fewer and showed more globular shape and shorter cytoplasmic processes in comparison to control cells. The immunocytochemical study with anti-aromatase antibody revealed that cells exposed to 360 µM 3-nitro-L-tyrosine were significantly more immunoreactive than control cells. Thus, it can be postulated that the oxidant effects of the amino acid analogue 3-nitro-L-tyrosine could be counterbalanced by an increase in aromatase expression that in turn can lead to the formation of neuroprotective estradiol via aromatization of testosterone.

Morphology, Morphometry and Spatial Distribution of Secondary Osteons in Equine Femur

A high number of differences exist in bone histological features depending on the species, breed, age and bone. Moreover, osteon distribution may vary in the different sides of a bone as a consequence of different biomechanical strains. The aim of this work was to study the distribution and morphology of osteons in different sides of the equine femoral diaphysis with the attempt to correlate them to the main strains operating on them. The following parameters of secondary osteons and Haversian canals were measured in the transverse sections of diaphyses: perimeter, area, minimum and maximum diameter, eccentricity and osteon population density. A typical Haversian tissue was observed with elliptic secondary osteons consisting in about 10 well‐defined lamellae surrounding a circular Haversian canal. Quantitative analysis displays a different population density of secondary osteons depending on the side. The caudal and medial sides, where compression strains are higher, have more secondary osteons in comparison with the cranial and lateral sides, where tension strains are prevalent. These data suggest that secondary osteon population density may depend on the predominant strains. Even the elliptical shape of secondary osteons may be related to biomechanical strains, as their major axes are oriented cranio‐caudally parallel to prevalent strains.

Aluminum promotes neuronal plasticity events in a mouse neuroblastoma cell line

The effects of aluminum(III) on microtubular meshwork have been investigated using cultured murine neuroblastoma cells grown in a medium containing aluminum lactate at defined metal concentrations (10-20 microM). A role of aluminum(III) in promoting neuronal plasticity events is suggested. These events including sprouting and neurite outgrowth are associated with an increased tyrosine-tubulin (Tyr-Tub) expression, which can be due to the enhanced needs of recently formed, highly dynamic microtubules typical of neuronal plasticity. After 48 and 72 h aluminum exposure, an upregulation of Tyr-Tub expression is detected and this is concentration-dependent. A high amount of Tyr-Tub is observed also in non-treated cells, although later than in aluminum-exposed cells. Thus, it is possible that aluminum(III) accelerates neuronal plasticity events, for which Tyr-Tub is confirmed to be a useful marker.

Androgen receptor immunoreactivity in rat occipital cortex after callosotomy

Gonadal steroidogenesis can be influenced by direct neural links between the central nervous system and the gonads. It is known that androgen receptor (AR) is expressed in many areas of the rat brain involved in neuroendocrine control of reproduction,such as the cerebral cortex.It has been recently shown that the occipital cortex exerts an inhibitory effect on testicular stereoidogenesis by a pituitary-independent neural mechanism. Moreover, the complete transection of the corpus callosum leads to an increase in testosterone (T) secretion of hemigonadectomized rats. The present study was undertaken to analyze the possible corticocortical influences regulating male reproductive activities. Adult male Wistar rats were divided into 4 groups: 1) intact animals as control; 2) rats undergoing sham callosotomy; 3) posterior callosotomy; 4) gonadectomy and posterior callosotomy. Western blot analysis showed no remarkable variations in cortical AR expression in any of the groups except in group I where a significant decrease in AR levels was found. Similarly, both immunocytochemical study and cell count estimation showed a lower AR immunoreactivity in occipital cortex of callosotomized rats than in other groups. In addition, there was no difference in serum T and LH concentration between sham-callosotomized and callosotomized rats. In conclusion, our results showthat posterior callosotomy led to a reduction in AR in the right occipital cortex suggesting a putative inhibiting effect of the contralateral cortical area.

Investigation of the effects of Lycium barbarum polysaccharides against cadmium induced damage in testis

This study describes the effects of Lycium barbarum polysaccharides (LBP) on testicular damage induced by cadmium (Cd). Adult male rats were i.p. injected with CdCl2 (4mg/Kg, once) with or without LBP pretreatment (300mg/Kg orally, once a day, for 30days). Testis weight, morphological/histological structure and oxidative stress parameters were evaluated. Several adverse effects were observed after CdCl2 injection, with a significant decrease in body/testis weight ratio (P<0.05), gross morphological changes with hyperemia of the parenchyma, increased volume and alteration in the structure of the seminiferous tubules. Furthermore, Cd intoxication caused a significant decrease of glutathione (GSH) and Trolox equivalent antioxidant capacity (TEAC) in testis (P<0.05) together with a significant increase (P<0.01) of 3-nitro-l-tyrosine (3NT) while malondialdehyde (MDA) did not change. LBP pretreatment caused slight signs of improvement in the morphology of the seminiferous tubules. Our results confirm that Cd induces testicular damage and suggest the oxidative stress involvement. LBP could ameliorate Cd testicular damage but further investigations are needed.

Morphological and quantitative analysis on α-tubulin modifications in glioblastoma cells

Glioblastoma is one of the primary tumors of the brain with high invasiveness and lethality. In the study of its pathophysiology in recent years much attention has been paid to the microtubular network, but exclusively to β-III tubulin, whose presence in glioblastoma cells is associated with the degree of malignancy and diffusion. As is well known, the microtubular network performs its many functions thanks to various post-translational modifications, most of which affect the α-tubulin subunit. These modifications, able to coexist in the same microtubule, bind certain driving and cargo proteins, deeply influencing cellular functions. Since there are no data in the literature about the diverse post-translational modifications of tubulin in glioblastoma cells, this work aims to fill this gap. In the present work, through immunofluorescence, morphological analysis and Western blot, we studied the pattern of tyrosinated, detyrosinated, delta 2 (Δ2), acetylated and polyglutamylated tubulin. We detected good immunopositivity in fluorescence for almost all the modifications examined. Only Δ2 showed a very low signal. Western blot displayed that the most abundant tubulin modifications in glioblastoma cells were tyrosinated, acetylated and polyglutamylated. Morphological evaluation revealed that these modifications were more present along the cytoplasmic extensions, less evident around the cell body and always strongly evident in the mitotic spindles of the dividing cells. For the first time, the most abundant post-translational modifications and their cellular compartmentalization in glioblastoma cells have been highlighted, suggesting a novel approach in the study of their microtubular network and in the search of new experimental therapeutic strategies.