Histology and histopathology Vol.27, nº12 (2012)
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- PublicationOpen AccessExpression and localization of VEGF receptors in human fetal skeletal tissues(F. Hernández y Juan F. Madrid. Universidad de Murcia. Departamento de Biología Celular e Histología, 2012) Marini, Mirca; Sarchielli, Erica; Toce, Mariateresa; Acocella, Alessandro; Bertolai, Roberto; Ciulli, Carlotta; Orlando, Claudio; Sgambati, Eleonora; Vannelli, Gabriella BarbaraDuring development the vertebrate skeleton is the product of deriving cells from distinct embryonic lineages. The craniofacial skeleton is formed by migrating cranial neural crest cells, whereas the axial and limb skeletons are derived from mesodermal cells. The Vascular Endothelial Growth Factors (VEGFs) / receptors (VEGFRs) system plays an important role in angiogenesis, as well as osteogenesis, during bone development, growth, and remodeling, attracting endothelial cells and osteoclasts and stimulating osteoblast differentiation. Recent evidence has shown that during development VEGFR-3 is also expressed in neural and glial precursors of forebrain and cerebellum, as well as in the eye. In this study, we found that VEGFR-1, VEGFR-2 and VEGFR-3 are expressed in human bone both in fetal and adult life. The gene expression levels were significantly higher in fetal samples especially in mandibles. In addition, higher levels of VEGFR-3 in orofacial district were confirmed by western blotting analysis. We also observed that in fetal mandibular samples VEGFRs colocalized in several osteoblasts, osteoclasts and osteoprogenitor cells. Furthermore, some cells coexpressed VEGFR-3 and ET-1, a marker of neural crest cells. The results demonstrated different expression of VEGFRs in human mandibular and femoral bones which could be correlated to their different structure, function and development during organogenesis. VEGFR-3 might represent a specific signal for ectomesenchymal lineage differentiation during early human development.
- PublicationOpen AccessProposed mechanism in the change of cellular composition in the outer medullary collecting duct during potassium homeostasis(F. Hernández y Juan F. Madrid. Universidad de Murcia. Departamento de Biología Celular e Histología, 2012) Park, Eun-Young; Kim, Wan-Young; Kim, Yu-Mi; Lee, Jeong-Hwa; Han, Ki-Hwan; Weiner, I. David; Kim, JinPotassium depletion (K+-D) induces hypertrophy and hyperplasia of collecting duct cells, and potassium repletion (K+-R) induces regression of these changes. The purpose of this study was to examine the time courses of the changes in cellular composition, the origin of intercalated cells (ICs) and the mechanism responsible for these changes. SD rats received K+-depleted diets for 1, 7, or 14 days. After K+-D for 14 days some of the rats received normal diets for 1, 3, 5, or 7 days. In the inner stripe of the outer medulla, K+-D increased significantly the number and proportion of H+-ATPase-positive ICs, but decreased the proportion of H+-ATPase-negative principal cells (PCs). However, proliferation was limited to H+-ATPase-negative PCs. During K+-R, the cellular composition was recovered to control level. Apoptosis increased during K+-R and exclusively limited in H+-ATPase-negative PCs. Double immunolabeling with antibodies to PC and IC markers identified both cells negative or positive for all markers during both K+-D and K+-R. Electron microscopic observation showed that ultrastructure of AE1-positive some cells were similar to AE1-negative some cells during K+-R. LC3 protein expression increased significantly and autophagic vacuoles appeared particularly in PCs on days 14 of K+-D and in ICs on days 3 of K+-R. These results suggest that PCs and ICs may interconvert in response to changes in dietary K+ availability and that autophagic pathways may be involved in the interconversion.
- PublicationOpen AccessKidney pericytes: A novel therapeutic target in interstitial fibrosis(F. Hernández y Juan F. Madrid. Universidad de Murcia. Departamento de Biología Celular e Histología, 2012) Smith, Stuart W.; Schrimpf, Claudia; Parekh, Dipen J.; Venkatachalam, Manjeri; Duffield, Jeremy S.Chronic Kidney Disease affects approximately 8% of the population and contributes considerably to premature morbidity and mortality. Recently reported studies have highlighted an important role for resident microvascular pericytes in the pathogenesis of kidney fibrosis. Pericytes are emerging as the predominant source of the activated, matrix depositing, stromal cell population seen in progressive fibrosis. Further, pericyte activation leads to their detachment from the vasculature, triggers unstable microvasculature and leads to rarefaction. Strategies to modulate pericyte function in these processes are therefore therapeutically attractive. In this review we will first describe our current understanding of the structure and function of the pericyte and the role these cells play in angiogenesis and the pathogenesis of renal fibrosis. Novel therapeutic approaches targeting pericytes in murine models of renal disease will then be considered.
- PublicationOpen AccessCharacterization of the lectin binding pattern in human spermatozoa after swim-up selection(F. Hernández y Juan F. Madrid. Universidad de Murcia. Departamento de Biología Celular e Histología, 2012) Gómez-Torres, María José; Avilés, Manuel; Girela, Jose Luis; Murcia, Verónica; Fernández-Colom, Pedro José; Romeu, Alberto; Juan, Joaquín deCapacitation is characterized by a hyperactivated pattern of sperm motility. The acquisition of highly motility is present in the early stages of capacitation. Sperm progressive motility is one of the most important parameters for determining the suitability of semen for processing. However, previous studies have shown that some sperm showing good motility have membrane damage. The aim of our study was to characterize the lectin staining pattern on the sperm plasma membrane of unselected and selected human sperm of normozoospermic donors. Sperm selection was performed by the swim-up technique. Fourteen samples from healthy consenting donors classified as normozoospermic according to the World Health Organization were used. We observed changes in the distribution of the carbohydrate residues after the swim-up selection. With Triticum vulgaris, the most abundant pattern was dotted labeling all over the head plasma membrane in the unselected sperm. However, this lectin was distributed homogenously over the acrosomal region after selection. With Arachis hypogaea, the most abundant pattern in fresh sperm was a highly stained acrosomal region. In the highly motility sperm population, the most frequent pattern was dotted fluorescence on the acrosomal region and a highly stained equatorial segment. Meanwhile, with the Aleuria aurantia and Canavalia ensiformis lectins, the most representative patterns were the same before and after the swim-up selection. Our data indicate that modifications which occur in carbohydrate residues during swim-up selection could be important for the regulation of progressive motility and prepare the sperm for capacitation.
- PublicationOpen AccessVitellogenesis in Archigetes sieboldi Leuckart, 1878 (Cestoda, Caryophyllidea, Caryophyllaeidae), an intestinal parasite of carp (Cyprinus carpio L.)(F. Hernández y Juan F. Madrid. Universidad de Murcia. Departamento de Biología Celular e Histología, 2012) Bruňanská, Magdaléna; Mackiewicz, John S.; Nebesářová, JanaVitellogenesis in the caryophyllidean tapeworm Archigetes sieboldi Leuckart, 1878, from carp Cyprinus carpio L. in Slovakia, has been examined using transmission electron microscopy and cytochemical staining with periodic acid-thiosemicarbazide-silver proteinate (PA-TSC-SP) for glycogen. Vitelline follicles extend in two lateral bands in the medullary parenchyma along both sides of the monozoic body. They are surrounded by an external basal lamina and contain vitellocytes and an interstitial tissue. The general pattern of vitellogenesis is essentially like that of other caryophyllideans. It involves four stages: immature, early maturing, advanced maturing cells and mature vitellocytes. During vitellogenesis, a continuous increase in cell volume is accompanied by an extensive development of cell components engaged in shell globule formation, e.g. granular endoplasmic reticulum and Golgi. Shell globule clusters are membrane-bound. Nuclear and nucleolar transformation are associated with formation and storage of large amounts of intranuclear glycogen, a very specific feature of the Caryophyllidea. For the first time, (a) additional vitelline material in Archigetes is represented by lamellar bodies and (b) lipid droplets are described in the mature vitellocytes from vitelline follicles and vitelloduct of the Caryophyllidea. Our results indicate that there may be a double origin of lamellar bodies: either from the endoplasmic reticulum or through transformation of shell globule/shell globule clusters. Lamellar body clusters and some single lamellar bodies appear to have a membrane. Other ultrastructural features of vitellogenesis and/or vitellocyte in A. sieboldi from its vertebrate (fish) and invertebrate (oligochaete) hosts are briefly compared and contrasted with those in other caryophyllideans and/or Neodermata.
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