Histology and histopathology Vol.17, nº 3 (2002)
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- PublicationOpen AccessLocation of Zinc and 65Zn in spinal ganglia of the rat(Murcia : F. Hernández, 2002) Perez-Castejon, M.C.; Vera-Gil, A.; Lahoz, M.; Aisa, J.; Recreo, M.P.; Pes, N.; Serrano, P.; Barral, M.J.Following the works of Velazquez et al. (1999), Jo-Seung et al. (2000), Wang et al. (2001), Danscher et al. (2001) and the criteria of Zinc-containing neurons established by Frederickson et al.(2000), we have found the presence and localisation of Zinc in the neurons of the dorsal root ganglia of Wistar rat, by using Timm’s thecnique and by studying the autoradiographic uptake of 65Zn. The agreement between the results of both techniques allows us to classify these spinal ganglion neurons as Zinc-containing neurons and also, to confirm some of the results of Velazquez et al. (1999)
- PublicationOpen AccessImmunoexpression of the hepatocyte growth factor (HGF), HGF-receptor (c-met) and STAT3 on placental tissues from malformed fetuses(Murcia : F. Hernández, 2002) Trovato, M.; Grosso, Maddalena; Vitarelli, E.; Benvenga, S.; Trimarchi, F.; Barresi, G.To characterize the possible relationship between the expression of the HGF/HGF-R system with transcription factor STAT3, responsible for morphogenetic response of HGF stimulation, and the embryonic development alterations, we investigated, by immunohistochemistry, the expression of HGF, c-met and STAT3 in 9 placentas from malformed fetuses and 9 control placentas from non-malformed fetuses. The major and distinct patterns of expression characterizing the placentas from malformed fetuses were a higher percentage mean of stromal cells stained for HGF, c-met and STAT3 antibodies (60%, 66% and 54%, respectively on fibroblast cells and 44%, 57% and 42%, respectively on myofibroblast cells) and a lower percentage mean of cytotrophoblast cells stained for the same antibodies (2%, 2% and 1%, respectively), than in control placentas. In fact, in this latter group, the stromal fibroblast cells were stained in a percentage mean of 27%, 22% and 7%, respectively; the stromal myofibroblast cells in a percentage mean of 5%, 6% and 2%, respectively and the cytotrophoblast cells in a percentage mean of 25%, 34% and 18%, respectively. The expression of each antibody on stromal cells in both groups suggests an alternative role of the HGF/HGF-R system activating the via STAT3 transdution and operating on placental tissues, overall in organogenesis alteration conditions. This immunohistochemical approach could be used in the diagnostic practice of pathologists on chorionic villi biopsy when genetic alterations are absent and ultrasound aspects are doubtful for malformations.
- PublicationOpen AccessExpression of p53 and its transcriptional target genes mRNAs in the ethylnitrosourea-induced apoptosis and cell cycle arrest in the fetal central nervous system(Murcia : F. Hernández, 2002) Katayama, K.; Ohtsuka, R.; Takai, H.; Nakayama, Hiroyuki; Doi, K.Ethylnitrosourea (ENU) is an alkylating agent and we previously clarified that it induced apoptosis and cell cycle arrest in the fetal central nervous system (CNS). In the present study, we studied the expression of p53 and its transcriptional target genes to investigate the role of p53 in the ENU-induced apoptosis and cell cycle arrest in the fetal CNS following the administration to dams on day 13 of gestation (GD13). Although the enhancement of p53 mRNA expression was not detected by reverse transcription and polymerase chain reaction (RT-PCR), p53-positive signals were detected immunohistochemically in the nuclei of neuroepithelial cells of the ENU-administered fetuses from 1 hour after treatment (HAT) to 12HAT, and they were most intensive at 3HAT. On the other hand, p53-positive signals were scarcely detected in the control fetuses. Among the p53 target genes, the expression of p21, bax, cyclinG1 and fas mRNAs increased and peaked at 6HAT. In addition, strong immunoreactivity for p21 was detected in the nuclei of neuroepithelial cells of the fetuses at 6HAT. The expression of p53 protein increased prior to the induction of apoptosis and cell cycle arrest, and transcription of its target genes was also activated. The present results suggest that ENU may induce apoptosis and cell cycle arrest in the fetal neuroepithelial cells in a p53-dependent manner.
- PublicationOpen AccessA micro-anatomical model of the distribution of myocardial endomysial collagen(Murcia : F. Hernández, 2002) Macchiarelli, G.; Ohtani, O.; Nottola, S.A.; Stallone, T.; Camboni, A.; Prado, I.M.; Motta, P.M.Myocardial connective tissue probably provides passive support for regulating heart tensile strength and stiffness and ultimately for controlling heart mechanics through its endomysial part. However, endomysial collagen micro-arrangement is still a matter of debate. In order to define the fine distribution of left ventricle endomysial collagen, we applied the NaOHscanning electron microscopy (SEM) maceration method (one of the techniques of choice for studying collagen micro-arrangement) to rabbit heart. Gomori-reticulum staining was used for correlated light microscopy (LM) observations. The SEM-NaOH method allowed isolation of collagen by removing other extracellular matrix components and cells and preserved collagen structure and position. Endomysial collagen appeared arranged in laminae that delimited the lacunae that were left empty by macerated myocytes and small vessels (mostly capillaries). These laminae were formed by reticular fibers, as confirmed by LM observations of Gomorireticulum- stained samples, and were organized in irregularly meshed networks made of thin (single) and thick (composed) filaments. In longitudinal views, collagen laminae extended the entire length of lacunae. In transversal views, the cut surface of the laminae appeared to be made of collagen bundles. These observations provide an updated microanatomical view of endomysial collagen distribution, which integrates previous studies. This model is based on the evidence that collagen laminae enveloped the surface of small vessels and myocytes. Thus, a type of myocyte-myocyte or capillary-myocyte "laminar connection" anchored to the entire cell length here is emphasized, rather than a type of "strut connection" anchored to defined loci, as usually described. This structure explains better how endomysium may provide the necessary support for heart compliance and protection against overstretch.
- PublicationOpen AccessRab3D a regulator of exocytosis in non-neuronal cells(Murcia : F. Hernández, 2002) Millar, A.L.; Pavlos, N.J.; Xu, J.; Zheng, M.H.Rab3D, a small Ras-like GTPase, is a key regulator of intracellular vesicle transport during exocytosis. It has been shown that Rab3 GTPases are abundant in cells with regulated secretory pathways and are thought to confer the specificity of docking and fusion during regulated exocytosis. Unlike other Rab3 isoforms, Rab3D is enriched in a number of nonneuronal tissues and is localised to secretory granules in the cytoplasm of these cells. The structure of Rab3D exhibits all of the conserved domains from the Rab family and also contains hypervariable N- and Cterminal regions. Rab3D undergoes post-translational isoprenylation and cycles between GDP- and GTPbound forms. Apart from the factors involved in the Rab activation cycle, few Rab3D effector proteins have been identified to date. Nevertheless, it has long been suggested that Rab3D plays a role in regulated exocytotic processes as well as apically directed transcytosis. This review summarises the recent work on the biological function, structural integrity and molecular interactions of Rab3D in non-neuronal cells.