Histology and histopathology Vol.25, nº7 (2010)
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- PublicationOpen AccessComparison of testis structure, function and thyroid hormone levels in control C57BL/6 mice and anti-mullerian hormone over expressing mice(Murcia: F. Hernández, 2010) Chamindrani Mendis-Handagama, S.M.L.; Siril Ariyaratne, H.B.; Fecteau, Kellie A.; Grizzle, Judith M.; Jayasundera, Nilanthi K.Anti-Mullerian hormone (AMH) is considered as a negative regulator of postnatal Leydig cell (LC) differentiation, because AMH over expressing mice (Mt-hAMH mice) testes are deficient in LC. Therefore, in the present study Mt-hAMH mice was used as a model to examine the process of postnatal LC differentiation. Testis structure-function studies were performed in age-matching Mt-hAMH and C57BL/6 (controls) mice; testicular components were quantified and circulating testosterone and thyroid hormone levels (thyroxine/T4 and triiodothyronine/T3; necessary for postnatal LC differentiation) were determined. Results revealed that Mt-hAMH mice were heavier and their testis weights were smaller compared to controls. Mast cells were present in Mt-AMH testis interstitium, but absent in controls. The absolute volumes of seminiferous tubules (ST), testis interstitium, LC and blood vessels per testis were lower and lymphatic space was higher in Mt-hAMH mice than in controls (p<0.05). The average cell LC volume and their number per testis, ST length, plasma testosterone, luteinizing hormone-stimulated testosterone secretion per testis and per LC in vitro, plasma T4 and T3 were significantly lower in Mt-hAMH mice compared to controls (p<0.05). Increased body weight in Mt-hAMH mice could be attributed to the reduced T4 and T3. Reduced testis weight in Mt-AMH mice is explained by the reduced ST volume in them. Reduced plasma testosterone, testicular and LC testosterone secretion in vitro in Mt-hAMH mice can be explained by the reduced number, size and steroidogenic potential of LC in Mt-hAMH mice. Study revealed several structure-function deficiencies in Mt-AMH mouse compared to controls, which were not documented in previous investigations. As hypothyroidism causes arrest in postnatal LC differentiation, it is suggested that the reduced LC number in Mt-hAMH testes could be at least in part due to their reduced thyroid hormone levels. However, latter concept needs to be further tested in future investigations.
- PublicationOpen AccessClaudin-7 protein differentiates canine cholangiocarcinoma from hepatocellular carcinoma(Murcia : F. Hernández, 2010) Jakab, Cs.; Kiss, A.; Schaff, Z.; Szabó, Z.; Rusvai, M.; Gálfi, P.; Szabára, Á.; Sterczer, A.; Kulka, J.The aim of the present study was to characterise the expression pattern of claudin-7 tight junction protein in canine normal liver, hyperplastic and primary neoplastic lesions of the canine liver and whether this tight junction protein can help differentiate canine cholangiocarcinomas from canine hepatocellular carcinomas. Methods and results: Necropsy samples included 15 canine normal liver tissue samples, 10 hepatocellular nodular hyperplasias, 6 hepatocellular adenomas, 15 well-differentiated and 6 poorly differentiated hepatocellular carcinomas, 6 cholangiocellular hyperplasias, 10 cholangiocellular adenomas, 15 well-differentiated and 6 poorly differentiated cholangiocarcinomas, 6 normal extrahepatic bile ducts, 8 normal gall bladder tissue samples, and 5 cystic mucinous hyperplasias of the gall bladder. In all canine normal liver tissue samples the hepatocytes were negative for claudin-7 and the normal biliary epithelial cells showed intense basolateral membrane claudin-7 positivity. In all cholangiocellular hyperplasia samples and in all cholangiocellular adenoma samples the benign cholangiocytes showed intense basolateral membrane positivity for claudin-7. In all samples of the well-differentiated and poorly differentiated cholangiocarcinomas, the malignant neoplastic biliary epithelial cells showed intense basolateral membrane positivity for claudin-7. Neither the hyperplastic nodules of the liver cells nor the hepatocellular adenomas reacted with claudin-7. The well-differentiated and poorly differentiated hepatocellular cancers were negative for claudin-7. The epithelial cells of canine normal extrahepatic bile ducts, gall bladder and cystic mucinous hyperplasias of the gall bladder showed intense basolateral membrane positivity for claudin-7. Differences in the intensity of claudin-7 reaction were not apparent among different types of proliferative lesions of cholangiocytes or degrees of cellular differentiation of neoplastic biliary epithelial cells. Conclusion: Consequently, we hypothesize that claudin-7 is an excellent immunohistochemical marker of the cholangiocellular differentiation in canines and can be used to detect benign and malignant proliferative lesions of the canine biliary tract. It can also help to differentiate canine cholangiocarcinomas from hepatocellular carcinomas.
- PublicationOpen AccessAnimal models for retinitis pigmentosa induced by MNU; disease progression, mechanisms and therapeutic trials(Murcia : F. Hernández, 2010) Tsubura, A.; Yoshizawa, K.; Kuwata, M.; Uehara, N.Retinitis pigmentosa (RP) is a group of inherited neurodegenerative diseases in humans characterized by loss of photoreceptor cells leading to visual disturbance and eventually to blindness. A single systemic administration of N-methyl-N-nitrosourea (MNU) causes retinal degeneration in various animal species. The retinal degeneration is highly reproducible, and the photoreceptor cell loss occurs within seven days after MNU administration via apoptosis resembling human RP. Here, we describe the disease progression, disease mechanisms, and therapeutic trials of MNUinduced retinal degeneration.
- PublicationOpen AccessPrimary cilia in fibroblast-like type B synoviocytes lie within a cilium pit, a site of endocytosis(Murcia : F. Hernández, 2010) Rattner, Jerome B.; Sciore, Paul; Ou, Young; van der Hoorn, Frans A.; Lo, I.K.Y.The synovium is a thin connective tissue that lines the joint space of free moving articulations. In this report, the expression, structure, and composition of non-motile (primary) cilia in fibroblast-like synoviocytes (FLS) that populate the synovium have been studied. Primary cilia are non-motile, microtubule-based organelles that have been found in a variety of vertebrate cell types. We document that primary cilia are expressed in normal human synovium FLS, cultured human FLS, and FLS cells present in human synovial fluid, and that the cellular region occupied by the primary cilium shows a similar and highly defined architecture within these FLS. This architecture includes the presence of a unique structure that surrounds the lower portion of the cilium shaft. This structure, given the term cilium-pit, includes a space, the pit reservoir. Actin filament bundles surround the cilium-pit, and when these bundles are removed experimentally the volume of the cilium-pit and its continuity with the extracellular environment changes. Finally, this study documents that the cilium-pit is a site of endocytosis and is also the site for the localization of receptors (TNF receptors TNFR1 and TNFR2) associated with synoviocyte function. Taken together, the results of the present study suggest that the FLS cilium-pit functions to regulate the exposure of the primary cilium, both spatially and temporally to extracellular molecules and to couple primary cilium based signaling pathways with those linked to endocytosis.
- PublicationOpen AccessHistopathological and parasitological investigations of ear healthy skin of dogs naturally and experimentally infected with Leishmania (Leishmania) chagasi(Murcia : F. Hernández, 2010) Figueiredo, María Marta; Perlatto Moura, Eliane; Costa, Miriam María; Ribeiro, Vitor Marcio; Michalick, Marilene Suzan; Tafuri, Washington Luiz; Tafuri, Wagner LuizAlthough 90% of clinical cases of American visceral leishmaniasis (AVL) occur in the northeastern region of Brazil, the incidence of cases in recent years has increased in southeastern states such as Minas Gerais (MG), where the disease has been reported in several cities, including Belo Horizonte, the state capital. Some studies have shown a strong correlation between the incidence of AVL and canine visceral leishmaniasis (CVL) in Belo Horizonte. A study of 108 dogs with parasite Leishmania chagasi detected by immunohistochemistry in healthy ear skin was obtained from two distinct geographical areas: 55 from a metropolitan area of the municipality (Santa Luzia, MG) and 53 dogs from a central area of Belo Horizonte. In parallel, a group of 10 beagles were experimentally infected with L. chagasi. Considering the clinical aspects of all naturally infected dogs, symptomatic dogs were more frequent than asymptomatic ones, especially animals from the metropolitan area compared with the central area (79.6% and 20.3%, respectively). A chronic exudate was observed in the ear of 51 out of 55 dogs naturally infected from the metropolitan area (92.7%) and 45 out of 53 dogs naturally infected from the central area (84.9%). Importantly, asymptomatic dogs from the central area harbor more parasites in the skin than the asymptomatic ones from the metropolitan area. In addition, a profound difference was noted in the intensity of the inflammatory reaction and parasite load in the skin of experimental infected dogs.
- PublicationOpen AccessSynthetic oligodeoxynucleotides induce MAP kinases activation in murine TIB-73 hepatocytes(Murcia : F. Hernández, 2010) Chicano Saura, Antonio; Ruiz Alcaraz, Antonio José; Lizana, Ana; Martín-Orozco Santiago, María Elena; Ruiz Alcaraz, Antonio JoséAims: In this work we aimed to investigate the expression of TLR9 protein in the murine hepatocyte cell line TIB-73, compared to macrophage-like J774 cells, by Western blot analysis, and the role played by ERK 1/2 MAP kinase in the intracellular signals triggered by stimulation with CpG and non-CpG phosphodiester-ODN, and their more stable phosphorothioate-modified analogues. Results: TIB-73 hepatocytes express TLR9 protein. CpG and non-CpG ODN stimulation activated ERK 1/2 MAPK signal pathway in both hepatocytes and J774 murine macrophages. As expected, their phosphorothioate-CpG and non-CpG ODN analogues induced higher levels of ERK1/2 phosphorylation in TIB-73 cells, even higher than that induced in J774 cells under the same conditions. Phosphorylation of ERK 1/2 induced by synthetic ODN is dose-response dependent, being maximal at 100 µg/ml. Pretreatment of hepatocytes with an inhibitor of MEK-1 abrogated phosphorylation of ERK1/2 kinase. Conclusions: TIB-73 hepatocytes constitutively express TLR9 and respond to synthetic ODN stimulation through a high ERK1/2 phosphorylation independent of CpG motifs. Slight differences were found on ERK1/2 activation when using phosphorothioate versus phosphodiester oligonucleotides.
- PublicationOpen AccessThe Grueneberg ganglion, a novel sensory system in the nose(Murcia : F. Hernández, 2010) Fleischer, Joerg; Breer, HeinzWithin the nasal epithelium of mammals, there are several compartments which are populated with neuronal cells. One of them – the so-called Grueneberg ganglion – is composed of ciliated neurons residing in the anterior region of the nose. Although cells of the Grueneberg ganglion lack direct contact with the lumen of the nasal cavity, they are endowed with features indicative of olfactory sensory neurons, such as the olfactory marker protein and distinct olfactory receptors, as well as projection of axonal processes to the olfactory bulb of the brain. These findings have led to the notion that the Grueneberg ganglion might be a novel olfactory subsystem; a concept which was lately supported by the observation that chemical cues activate Grueneberg ganglion neurons. Unexpectedly, it was recently found that these cells also respond to cool ambient temperatures, presumably via a signaling pathway mediated by second messengers. Thus, the Grueneberg ganglion may operate as a dual sensory organ involved in the detection of both chemical and thermal stimuli.
- PublicationOpen AccessNF - KB function in the human myometrium during pregnancy and parturition(Murcia : F. Hernández, 2010) Cookson, Victoria J.; Chapman, RobertInteractions between the nuclear factor kappaB (NF-κB) family of proteins (RelA, RelB, c-Rel, p50 and p52) and DNA are vital for cells to function normally; for example, in the human myometrium, NF- κB-regulated pro-inflammatory mediators, including TNFα, IL-1ß, IL-8 and COX-2 are associated with the onset of labour. NF-κB, however, regulates the expression of over 400 genes, although it is unlikely these would all be activated in concert by a single inducer. At present, defining the role of the NF-κB RelA:p50 dimer, which governs a number of inflammatory promoters, is at the forefront of the parturition research field. However, to over-look the function of other family members and how they may regulate alternative signalling networks within reproductive tissues, only serves to ensure we will never fully understand the molecular circuitry influenced by this family of transcription factors. Consequently this review highlights other mechanisms by which the NF- κB family of regulators have been shown to function in other systems and how they may readily translate to understanding the regulation underpinning human parturition.
- PublicationOpen AccessMolecules of cell adhesion and extracellular matrix proteolysis in oral squamous cell carcinoma(Murcia : F. Hernández, 2010) Shi, Zonggao; Stack, M. SharonOral squamous cell carcinoma (OSCC) is the most common malignancy of the oral cavity with a poor 5-year survival rate, due in large part to the presence of metastatic disease at initial diagnosis. In recent years, a number of studies have examined the oral tumor microenvironment to asses the potential dynamic balance between extracellular matrix deposition and proteolytic degradation as well as the cellular adhesion molecules that mediate adhesion to matrix and regulate tissue cohesion. The objective of this review is to provide a brief overview of the major matrix components, adhesion molecules and proteolytic enzymes in the oral tumor microenvironment and to summarize recent findings regarding the role of these complex molecular players in oral tumor progression.
- PublicationOpen AccessThe role of prostaglandin E2 in acute acetaminophen hepatotoxicity in mice(Murcia : F. Hernández, 2010) Ćavar, Ivan; Kelava, Tomislav; Vukojevic, Katarina; Saraga-Babić, Mirna; Čulo, FilipProstaglandin E2 (PGE2), which is synthesized by many cell types, has a cytoprotective effect in the gastrointestinal tract and in several other tissues and cells. On the other hand, overdose or chronic use of a high dose of acetaminophen (Paracetamol, APAP) is a major cause of acute liver failure in the western world. These observations prompted us to investigate whether PGE2 plays a role in host defence to toxic effect of APAP. (CBAT6T6xC57Bl/6)F1 hybrid mice of both sexes were intoxicated with a single lethal or high sublethal dose of APAP, which was administered to animals by oral gavage. Stabile analogue of PGE2, 16,16-dimethyl PGE2 (dmPGE2), or inhibitor of its production, CAY10526, were given intraperitoneally (i.p.) 30 minutes before or 2 hours after APAP administration. The toxicity of APAP was determined by observing the survival of mice during 48 hours, by measuring concentration of alanine-aminotransferase (ALT) in plasma 20-22 hours after APAP administration and by liver histology. The results have shown that PGE2 exhibits a strong hepatoprotective effect when it is given to mice either before or after APAP, while CAY10526 demonstrated mainly the opposite effect. Immunohistochemical or immunofluorescent examinations in the liver tissue generally support these findings, suggesting that PGE2 inhibited APAP-induced activation of nuclear factor kappa B (NF-κB). Similarly, PGE2 down regulated the activity of inducible nitric oxide synthase (iNOS), which was up regulated by APAP. Thus, by these and perhaps by other mechanisms, PGE2 contributes to the defence of the organism to noxious effects of xenobiotics on the liver.
- PublicationOpen AccessExpression and distribution of cytokeratin 8-18 intermediate filaments in bovine antral follicles and corpus luteum: An intrinsic mechanism of resistance to apoptosis?(Murcia : F. Hernández, 2010) Townson, David H.; Putnam, Amanda N.; Sullivan, Brian T.; Guo, Lankai; Irving-Rodgers, Helen F.Apoptosis is a mechanism of cell elimination during follicular atresia and luteal regression. Recent evidence suggests sensitivity to apoptosis in some cell types is partly dependent upon cytokeratin-containing intermediate filaments. Specifically, cytokeratin 8/18 (CK8/18) filaments are thought to impart resistance to apoptosis. Here, cytokeratin filament expression within bovine ovarian follicles and corpora lutea (CL) was characterized and the potential relationship between cellspecific CK8/18 expression and apoptosis explored. Immunoprecipitation and western blot analysis confirmed CK8 associates with CK18 to form CK8/18 heterodimeric filaments within bovine ovarian cells. Immunostaining revealed populations of CK18-positive (CK18+) cells in healthy growing follicles that increased in postovulatory follicles. Atretic follicles at all stages of atresia also contained some CK18+ cells. However, no CK18+ cells were detected in primordial or primary follicles. In CL, developing CL contained a higher proportion of CK18+ cells (~35%, range 30-70%) than mature CL (~16%) and regressing CL (~5%; P<0.05, n = 3-5 CL/stage), suggesting CK8/18 filament expression diminishes over time, as luteal cells become more susceptible to apoptosis. Dual-fluorescence labeling for CK18 and a cell death marker (TUNEL labeling) confirmed this view, demonstrating less death of CK18+ than CK18- luteal cells throughout the estrous cycle (P<0.05). The results indicate differential expression of CK8/18 filaments occurs in cells of bovine ovarian follicles and CL throughout the estrous cycle. The prevalence and cell-specific pattern of cytokeratin expression in these structures is consistent with the concept these filaments might impart resistance to apoptosis in ovarian cells as is seen in other cell types.
- PublicationOpen AccessThe effects of nitric oxide inhibition prior to kainic acid treatment on neuro- and gliogenesis in the rat dentate gyrus in vivo and in vitro(Murcia: F. Hernández, 2010) Cosgrave, A. Siobhan; McKay, Jennifer S.; Morris, Richard; Quinn, John P.; Thippeswamy, ThimmasettappaTreatment with the nitric oxide synthase (NOS) inhibitor, L-NAME prior to the induction of seizures with kainic acid (KA) [L-NAME+KA] increases the expression of activity-dependent neuroprotective protein (ADNP) in cells in the subgranular zone (SGZ) of the rat dentate gyrus 3-days after seizure induction (Cosgrave et al., 2009). Using the incorporation of BrdU we found that this protocol [LNAME+KA] stimulates neuro- and gliogenesis. By comparison, L-NAME or KA alone produced smaller effects. Doublecortin+ (BrdU negative) neuroblasts in the SGZ also significantly increased with L-NAME+KA treatment, suggesting that L-NAME+KA cause more cells to differentiate into neurons. L-NAME alone increased BrdU+ astrocytes in the hilus implying that NO inhibits stem cell differentiation into astrocytes and may also influence their migration. Although NOS inhibition increased cell proliferation in vivo and in vitro it disrupted cell clustering as revealed by ADNP immunoreactivity. In vitro KA treatment resulted in eccentric nuclei, reduced neurite extension and branching in neurons and retracted processes of glia cells, these changes were inhibited with prior treatment of L-NAME suggesting that KA-induced NO production affects cell morphology. Consequently, this data suggests an important role for NO in regulating stem cell proliferation and their fate in the SGZ.