Browsing by Subject "Epithelium"
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- PublicationOpen AccessEpithelial component and intraepithelial lymphocytes of conjunctiva-associated lymphoid tissue in healthy children(Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2021) Cano-Suárez, Magnolia T.; Reinoso, Roberto; Martín, Carmen; Calonge, Margarita; Vallelado, Ana I.; Fernández, Itziar; Corell, Alfredo. Conjunctiva-associated lymphoid tissue (CALT) plays a key role in protecting the eye surface by initiating and regulating immune responses. The aim of this study was to investigate in healthy children the proportion of intraepithelial lymphocytes (IELs), the degree of viability and/or apoptosis and cell proliferation in three different topographic areas of the conjunctiva. Superior tarsal, superior bulbar, and inferior tarsalbulbarfornix conjunctival cells were collected by brush cytology (BC) from 24 healthy paediatric subjects (13 boys and 11 girls, mean age 6±2 years) who were to undergo strabismus correction surgery under general anaesthesia. Subsequently, these cells were analysed phenotypically and functionally by flow cytometry (FC). Flow cytometry analysis showed that not all the cells obtained by BC were of the epithelial lineage, but that there was a population of CD45+ cells (IELs) regularly present in the conjunctiva of healthy children. These IELs were mostly T-lymphocytes (CD3+) and Blymphocytes (CD19+), with higher levels of Tlymphocytes (CD3+) in the upper areas than in the inferior tarsal-bulbar-fornix, where the highest levels of B-lymphocytes (CD19+) were found. In the apoptosis assay, two groups of cell populations were differentiated by cell size and complexity (cytoplasmic granularity), with more complex cells predominating in the upper areas of the conjunctiva and less complex cells being more abundant in the inferior tarsal-bulbar-fornix. Finally, the proliferative capacity of the conjunctival epithelium was significantly higher in the upper tarsal zone than in the rest of the zones analysed. These results suggest that the epithelial component and the IELs of CALT are also regularly present in the conjunctiva of the healthy child, varying in phenotype, viability and cell proliferation according to the different conjunctival regions analysed, which could lead us to believe that each conjunctival zone plays a different, specific role in the regulation of the immune response at the ocular level.
- PublicationOpen AccessExpression of integrin αvβ3 in pig, dog and cattle(F. Hernández y Juan F. Madrid. Universidad de Murcia: Departamento de Biología Celular e Histología, 2001) Singh, B.; Rawlings, N.; Kaur, A.The avlB integrin, also known as vitronectin receptor, is an adhesive glycoprotein that promotes angiogenesis in the embryo and tumors such as melanoma. Integrin avID is one of the receptors for adenovirus and hantavirus. There is little information on the constitutive expression of this integrin especially in animal species that are used for biomedical research. We used light and elec tron microscope immunocytochemistry and western blots to determine integrin avB3 expression in seven organs in the pig, dog and cattle. Immunohistology showed the integrin expression on the epithelium of small intestine , bile duct and renal proximal convoluted tubules in three species. The airway epithelium revealed a weak reaction for integrin avB3. Skin showed the integrin in occasional extravascular cells while skeletal muscles were negative. The integrin was expressed only in bronchial vasculature in the lung and occasional dermal microvessels. Many mononuclear cells in the lung and spleen stained for integrin avB3. Immunogold electron microscopy revealed the expression on the epithelium but not on the vasculature of the small intestine. Western blots detected integrin avB3 in small intestine and lung but not in skeletal muscles. We conclude the integrin is expressed on the epithelium but not in the vasculature. The expression differs strikingly among organs in the same pecies although the inter-species differences are minor. Restriction of the integrin to absorptive epithelia of small intestine and kidney may suggest its putative role in endocytosis. Because the integrin is a receptor for adenovirus, these data may be relevant to gene therapy studies.
- PublicationOpen AccessMorphological differences among nerve fiber endings in the rat oral mucosa as revealed by methylene blue staining(Murcia : F. Hernández, 1996) Müller, T.The nerve fiber distribution in the oral mucosa of the soft palate and palatoglossal arch of the rat was studied by means of methylene blue supravital staining. it was focussed primarily on the dye uptake of intraepithelial nerve fibers. Differences in the morphology of nerve fiber terminations were found between these regions of the oral mucosa. In the soft palate, local accumulations of intraepithelial nerve fibers which branched and showed terminal enlargements were detected. Intra- and perigemmal nerve fibers of chemosensory corpuscles could be stained. In the palatoglossal arch, numerous elongated papillae were seen containing nerve fiber plexus showing a complicated arborization pattern. In part, the collaterals penetrated the epithelium. The soft palate contained only a small number of lower but broader papillae which were covered by a more expanded intraepithelial nerve fiber plexus. In both regions, anastomoses between the branches of single nerve fibers were sometimes seen. Solitary delicate nerve fiber endings were loosely distributed throughout the epithelia. In addition, intrapapillar nerve endings, which were enclosed by a slightly stained capsule, were intensely stained; they showed characteristic lateral protuberances. The Merkel's discs were visualized as the components of a terminal network of nerve fiber branches. The observed differences in the shape and locations of the nerve terminations suggest different functions of these nerve fibers. Due to the low costs of the staining procedure and its ease in handling, it is well-suited for a mappingof the innervation pattem of the whole oral mucosa
- PublicationOpen AccessOdontogenic jaw cysts: light and electron microscopical investigations(Murcia : F. Hernández, 1996) Domenici Lombardo, L.; Amunni, F.; Bergamini, M.; Romagnoli, P.Light and electron microscopy were used to analyze the epithelial lining of odontogenic cysts excised from edentulous regions of the jaws. Clinically, three cases were identified as keratocysts, and 21 cases as cysts other than keratocysts («non-keratocysts~)T. he epithelium of the former was found to achieve keratinization over most of the surface and to never contain mucus secreting cells. The epithelium of the latter appeared to be in part stratified squamous, with cells loosely connected to each other, and in part stratified columnar, with superficial cells connected to each other by tight junctions and secreting mucus. The results suggest that cysts arising from edentulous regions of the jaws may be either keratocysts or cysts with heterogeneous, non-keratinizing epithelium; the content of keratocysts can be formed mainly by shedding of comified epithelial layers, and that of non-keratocysts by mucus secretion from columnar epithelium associated to fluid filtration through non-keratinizing squamous epithelium.
- PublicationOpen AccessSite differences of Toll-like receptor expression in the mucous epithelium of rat small intestine(F. Hernández y J.F. Madrid. Murcia: Universidad de Murcia, Departamento de Biología Celular e Histología., 2011) Mantani, Youhei; Kamezaki, Aosa; Udayanga, Kankanam Gamage Sanath; Takahara, Ei-ichirou; Qi, Wang-Mei; Kawano, Junichi; Yokoyama, Toshifumi; Hoshi, Nobuhiko; Kitagawa, HiroshiToll-like receptors (TLRs) are known to recognize pathogen-associated molecular patterns and might function as receptors to detect microbes. In this study, the distribution of TLR-2, -4 and -9 were immunohistochemically investigated in the rat small intestine. As a result, TLR-2 was detected in the striated borders of villous columnar epithelial cells throughout the small intestine, except for the apices of a small number of intestinal villi. TLR-4 and -9 were detected in the striated borders of the villous columnar epithelial cells only in the duodenum. TLR-4-immunopositive minute granules were found in the apical cytoplasms of epithelial cells, subepithelial spaces and blood capillary lumina. TLR-2 and -4 were detected in the striated borders of undifferentiated epithelial cells and in the luminal substances of the intestinal crypts throughout the small intestine, but TLR-9 was not detected in the crypts throughout the small intestine. Only TLR-4 was detected in the secretory granules of Paneth cells in both the jejunal and ileal intestinal crypts. These findings suggest that duodenal TLRs might monitor indigenous bacteria proliferation in the upper alimentary tract, that TLR-2 might also monitor the proliferation of colonized indigenous bacteria throughout the small intestine, that the lack of TLR-2 at the villous apices might contribute to the settlement of indigenous bacteria, and that TLR-2 and -4 are secreted from intestinal crypts.
- PublicationOpen AccessStructure of the rat tracheal mucosa after chronic intermittent hypoxia or chronic hyperbaric oxygen therapy(Universidad de Murcia. Departamento de Biología Celular e Histología, 2016) Vera-Cruz, Paulo; Rito, Miguel; Diogo, Lucília; Zagalo, Carlos; dos Santos, José Martins; Monteiro, Maria Emília. Objective: This paper is aimed at identifying putative morphological changes induced in the rat’s tracheal mucosa by chronic hyperbaric oxygen (HBO) treatment or chronic intermittent hypoxia (CIH). Study Design: Tracheal samples were obtained from three groups of 11, 12 and 13 adult Wistar rats. The first group was submitted to 20 sessions of 100 min-long HBO treatment; the second group was submited to eucapnic CIH for 35 days; and the third group was not submitted to any CIH or HBO therapy. Methods: Four proximal tracheal rings were collected after sacrifice and neck dissection of the animals. The samples were processed for both light microscopy and morphometric analysis. Inflammatory leukocyte infiltration was evaluated by a semiquantitative method. Unpaired t test and Bernoulli distribution were applied to evaluate statistical differences in the data collected from the three groups. Results: Both CIH and HBO promote an increase in the thickness of the epithelium and of the basement membrane of the rat tracheal mucosa, as well as an increment in the number of infiltrating leukocytes, when compared with results seen in the untreated group. In the HBO group there was a significant lack of seromucous glands, as opposed to the results obtained in the CIH group. Conclusions: Chronic HBO and CIH exposure causes only minor changes in the architecture of the tracheal mucosa of the rat. The respiratory tract of the rat showed a mild inflammatory response when subject to variations of pressure and oxygen content. Apparently these effects do not constitute a critical issue on prescribing HBO treatments and in the management of sleep apnea patients.
- PublicationOpen AccessThe Ca2+-binding S100A2 protein is differentially expressed in epithelial tissue of glandular or squamous origin(Murcia : F. Hernández, 2002) Nagy, N.; Hoyaux, D.; Gielen, I.; Schafer, B.W.; Pochet, R.; Heizman, C.W.; Kiss, R.; Salmon, I.; Decaestecker, C.It has been previously shown that S100A2 is downregulated in tumor cells. The level of immunohistochemical S100A2 expression was therefore characterized in 424 normal and tumoral (benign and malignant) tissues of various origins, but mostly epithelial (with either glandular, squamous, respiratory or urothelial differentiation). We also investigated whether S100A2 could be co-localized with cytokeratin K14, an intermediate filament protein expressed in basal proliferative keratinocytes. Our data show that S100A2 has a low level of expression in non-epithelial tissue. In epithelial tissue S100A2 expression decreases remarkably in the tumors when compared to the normal specimens, and was correlated with the level of keratin K14. This decrease in S100A2 staining from normal to cancer cases is more pronounced in glandular than in squamous epithelial tissue. In addition, the patterns of S100A2 staining also differ between glandular and squamous tissue. These data suggest distinct functional roles for S100A2 in epithelial tissue of squamous or glandular origins.
- PublicationOpen AccessThe origin of human epithelial tissue(Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2023) Alaminos, Miguel; Campos, AntonioThe histological structure of human epithelial tissue is complex, but all epithelia share three major features: cohesion, polarity and attachment. These functions are mainly achieved by the presence of specialized structures such as intercellular junctions, polarity protein complexes and basement membranes. In the present review, we have analyzed the presence of each of these structures in several groups of animals that are considered to be at the base of the animal evolution tree. Interestingly, these characters seem to have evolved independently, and a careful histological and structural analysis of the phylogenetic tree shows different groups of animals in which epithelia are absent and groups in which cells show only some of the specialized structures found in differentiated epithelia. These findings could contribute to understand how epithelial tissues evolved and determine their current protective functions.
- PublicationOpen AccessThe role of apoptosis in pulmonary fibrosis(Murcia : F. Hernández, 2004) Kuwano, K.; Hagimoto, N.; Nakanishi, Y.Pulmonary fibrosis is a common response to various injuries to the lung. The resolution of a fibroproliferative response after lung injury is key to survival. Although there are various initiating factors or causes, the terminal stages are characterized by proliferation and progressive accumulation of connective tissue replacing normal functional parenchyma. Conventional therapy consisting of glucocorticoids or immunosuppressive drugs is usually ineffective in preventing progression of fibrosis. Further understanding of the molecular mechanisms of endothelial and epithelial cell injury, inflammatory reaction, fibroblast proliferation, collagen deposition and tissue remodeling, should lead to the development of effective treatments against pulmonary fibrosis. Evidence that apoptosis plays an important role in the pathophysiology of pulmonary fibrosis has been accumulated. We overview the role of apoptosis in each of the pathogenic events which have emerged from animal models and human tissue studies.
- PublicationOpen AccessThe spectrum of cytokeratins expressed in the adult human cornea, limbus and perilimbal conjunctiva(Murcia: F. Hernández, 2011) Merjava, Stanislava; Neuwirth, Ales; Tanzerova, Michaela; Jirsova, KaterinaThe aim of this study was to detect a spectrum of cytokeratins (CK) present in the adult human cornea, limbus and perilimbal conjunctiva. Cryosections from seven corneo-scleral discs were fixed, and indirect immunofluorescent staining was performed using antibodies directed against CK1-CK10 and CK13-CK20. The percentage of positive cells was calculated in the epithelium of the cornea, limbus and perilimbal conjunctiva. Quantitative real time RT-PCR (qRT-PCR) was used to detect CK6 and CK18 expression in the corneal and conjunctival epithelium. The most intense staining present throughout the cornea was observed for CK3, CK5 and CK14; CK19 was found at the corneal periphery only. CK4 and CK10/13 revealed mild to moderate positivity mostly in the superficial layers of the cornea. The suprabasal cell layers of all examined areas showed a strong positivity for CK16. A heterogeneous staining pattern with a centrifugal decrease in the signal was observed for CK8 and CK18. CK5/6, CK14 and CK19 were present in the limbus, where a positive signal for CK3 was observed in the suprabasal and superficial cells only. In contrast to the cornea, CK15 appeared in the basal and suprabasal layers of the limbus. The perilimbal conjunctiva showed strong immunostaining for CK10/13, CK14 and CK19. A moderate signal for CK7 was detected in the superficial layers of the conjunctiva. qRT-PCR confirmed CK6 and CK18 expression in the corneal and conjunctival epithelium. The detailed characterization of the corneal, limbal and perilimbal conjunctival epithelium under normal circumstances may be useful for characterizing the changes occurring under pathological conditions.