Estudo imuno-histoquímico da co-expressão de citoqueratinas, vimentina e actina em neoplasias de glândula salivar

Human salivary gland tumors originated from intercalated ducts present a broad range of histologic and cytologic patterns, mainly due to the presence of myoepithelial cells. The aim of this study is to verify the differentiation grade of neoplastic cells and a possible relation between myoepithelial cell differentiation and the presence of luminal secretory contents. The expression of vimentin and cytokeratin (CK) intermediate filaments, actin myofilament and epithelial membrane antigen (EMA) was investigated by double labeling immunocytochemical technique, in thirty salivary gland neoplasms: 5 pleomorphic adenomas, 5 myoepitheliomas, 3 basal cell adenomas, 7 adenoid cystic carcinomas (ACC) and 10 polimorphous low grade adenocarcinomas (PLGA). Tumors with intercalated duct differentiation (pleomorphic adenomas, basal cell adenomas and ACC) express CKs 7, 8, 18 and 19 in the luminal cells and coexpress eventually CK14 with these CKs. Some luminal cells stained with anti-EMA antibody, mainly where a secretory content in the lumen was observed. Outer ductal cells and other myoepithelial-like cells express vimentin, sometimes coexpressing actin and/or CK14 with vimentin. Plasmacytoid cells in myoepitheliomas and pleomorphic adenomas express vimentin and rarely CKs 7, 8, 18 and 19, sometimes coexpressing these CKs with CK14 but they are negative for the remaining antigens. Tumors without intercalated duct differentiation (solid basal cell adenoma and PLGA) express vimentin and CKs 7, 8, 14 and 18, sometimes coexpressing CKs 8 and 18 with CK14. In conclusion, in tumors with intercalated duct differentiation, myoepithelial cells express vimentin and sometimes coexpress actin and/or CK14 with vimentin, never coexpressing other CKs with vimentin. CK14 and actin are independently expressed by myoepithelial cells, so their expression is probably induced by different stimulus. However, the secretory function of luminal cells, visualized by EMA staining, ....

Avaliação da expressão de citoqueratinas na citologia esfoliativa da mucosa bucal de pacientes fumantes

The present study compared the expression of cytokeratins CK6, CK16 and CK19 and pan-cytokeratin (PAN) in oral mucosa cells between smokers and nonsmokers in order to determine the stage of cell differentiation and to consequently infer proliferative activity and expressions indicative of a potential for malignant differentiation. Thirty smokers and 30 non-smokers seen at the clinics of FOSJC-UNESP were screened. Smears were obtained from the left lateral border of the tongue with a cytobrush and slides were processed for immunohistochemistry using the antibodies reported Conventional microscopy was used for qualitative analysis. The results were analyzed statistically by the Z test, Fisher's exact test and comparison of two proportions (plus-4 confidence interval method). The expression of CK6 (p=0.002), CK16 (p=0.003), CK19 (p=0.0001) and PAN (p=0.008) was higher in oral mucosa smears from smokers compared to non- smokers. ln conclusion, increased epithelial proliferation is observed in the oral mucosa of smokers as demonstrated by the increased expression of CK6 and CKJ6, and these cells present alterations in epithelial maturation

Cryotolerance and global gene-expression patterns of Bos taurus indicus and Bos taurus taurus in vitro- and in vivo-produced blastocysts

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Análise da expressão gênica de pequenos RNAs derivados de tRNAs (tRFs) em plantas

Small non coding RNAs emerged as important characters in several biology aspects. Among then, the most studied are microRNAs (miRNAs) and short interfering RNAs (siRNAs), that regulate their target gene post-transcriptionally in plants, animals and RNAi pathway intermediates, respectively. Both of classes have similar biogenesis being processed by Dicer enzymes and subsequent association with Argonaute enzymes. In plants, miRNAs and siRNAs have important functions in development, genome integrity and biotic and abiotic stress responses. The advances in high-throughtput sequencing and in silico analisys provide the uncover of new small non coding RNAs classes, many of them with unknown functions and biogenesis. tRNA derived small RNAs (tRFs) are a small non coding RNA class, that have as precursor a tRNA molecule. These were uncovers in the last decade in many organisms and, recently, in plants. Recent works detected tRFs from different sizes, with different source portions of the mature tRNA molecule (5’ end; 3’ end, anti-codon loop) and some from the tRNA precursor (pre-tRNA), suggesting that may be a novel class of small RNA and not random degradation products. Works in humans showed that some tRFs are processed by the Dicer enzymes, have association with the Argonaute enzymes and cell differentiation, tumor appearance and gene silencing related functions. Works in Arabidopsis and pumpkin (Cucurbita maxima) showed, respectively, that the tRFs have nutritional stress response possible functions and long distance signaling function between source and drain tissues, and may affect the translation. The tRFs biogenesis in plants are, until now an unknown, absence information about it in the literature and its possible biological functions are few studied yet, making then interesting target for studies among the small non coding RNAs in plants

Os papéis dos RNAs não codificantes no desenvolvimento embrionário: um panorama geral

The genome of multicellular organisms shows a ruge index of RNA transcripts that are not protein coding. These ncRNAs act in housekeeping and genic regulation, as well in signaling and cell differentiation, crucial events to embryonic and ontogenetic development. Moreover, another events require the orderly expression these transcripts, as in cromossomic inactivation and genomic imprinting process, and their fail may cause several syndromes, malformations, illness and even death of affected individual. This review focus is to present the main acting pathways of ncRNAs already studied, as well to introduce the actual landscape of Dapper gene cluster and its performance in vertebrate development.

Morphological changes of mammalian nucleoli during spermatogenesis and their possible role in the chromatoid body assembling

Chromatoid body (CB) is a typical cytoplasmic organelle of germ cells, and it seems to be involved in RNA/protein accumulation for later germ-cell differentiation. Despite most of the events in mammals spermatogenesis had been widely described in the past decades and the increase in the studies related to the CB molecular composition and physiology, the origins and functions of this important structure of male germ cells are still unclear. The aims of this study were to describe the nucleolar cycle and also to find some relationship between the nucleolar organization and the CB assembling during the spermatogenesis in mammals. Cytochemical and cytogenetics analysis showed nucleolar fragmentation in post-pachytene spermatocytes and nucleolar reorganization in post-meiotic spermatids. Significant difference in the number and in the size of nucleoli between spermatogonia and round spermatids, as well as differences in the nucleolar position within the nucleus were also observed. Ultrastructural analysis showed the CB assembling in the cytoplasm of primary spermatocytes and the nucleolar fragmentation occurring at the same time. In conclusion our results suggest that the CB may play important roles during the spermatogenesis process in mammals and that its origin may be related to the nucleolar cycle during the meiotic cell cycle.

Indirect cytocompatibility of a low-concentrated hydrogen peroxide bleaching gel to odontoblast-like cells

Aim To assess the initial cytotoxicity and the late phenotype marker expression of odontoblast-like cells (MDPC-23) subjected to less aggressive in-office bleaching therapies. Methodology A 17.5% hydrogen peroxide (H2O2) gel was applied for 45, 15 or 5 min to enamel/dentine discs adapted to trans-wells positioned over cultured MDPC-23 cells. No treatment was performed on the negative control. Immediately after bleaching, the cell viability, gene expression of inflammatory mediators and quantification of H2O2 diffusion were evaluated. The ALP activity, DSPP and DMP-1 gene expression and mineralized nodule deposition (MND) were assessed at 7, 14 or 21 days post-bleaching and analysed statistically with Mann–Whitney U-tests (α = 5%). Results H2O2 diffusion, proportional to treatment time, was observed in all bleached groups. Reductions of approximately 31%, 21% and 13% in cell viability were observed for the 45-, 15- and 5-min groups, respectively. This reduction was significant (P < 0.05) for the 45- and 15-min groups, which also presented significant (P < 0.05) over-expression of inflammatory mediators. The 45-min group was associated with significant (P < 0.05) reductions in DMP-1/DSPP expression at all periods, relative to control. The ALP activity and MND were reduced only in initial periods. The 15-min group had less intense reduction of all markers, with no difference to control at 21 days. Conclusions The 17.5% H2O2 applied to tooth specimens for 5 min caused no alteration in the odontoblast-like cells. When this gel was applied for 45 or 15 min, a slight cytotoxicity, associated with alterations in phenotypic markers, was observed. However, cells were able to recover their functions up to 21 days post-bleaching.

Ovarian superstimulation using FSH combined with equine chorionic gonadotropin (eCG) upregulates mRNA encoding proteins involved with LH receptor intracellular signaling in granulosa cells from Nelore cows

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Investigação da ação da proteína anexina A1 sobre o processo de angiogênese induzido pelo fator de crescimento do endotélio vascular: modelos experimentais in vivo e in vitro

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Immunolocalization of myosin Va in the developing nervous system of embryonic chicks

Myosins are molecular motors associated with the actin cytoskeleton that participate in the mechanisms of cellular motility. During the development of the nervous system, migration of nerve cells to specific sites, extension of growth cones, and axonal transport are dramatic manifestations of cellular motility. We demonstrate, via immunoblots, the expression of myosin Va during early stages of embryonic development in chicks, extending from the blastocyst period to the beginning of the fetal period. The expression of myosin Va in specific regions and cellular structures of the nervous system during these early stages was determined by immunocytochemistry using a polyclonal antibody. Whole mounts of chick embryos at 24-30-h stages showed intense immunoreactivity of the neural tube in formation along its full extent. Cross-sections at these stages of development showed strong labeling in neuroepithelial cells at the basal and apical regions of the neural tube wall. Embryos at more advanced periods of development (48h and 72 h) showed distinctive immunolabeling of neuroepithelial cells, neuroblasts and their cytoplasmic extensions in the mantle layer of the stratified neural tube wall, and neuroblasts and their cytoplasmic extensions in the internal wall of the optic cup, as well as a striking labeling of cells in the apparent nuclei of cranial nerves and budding fibers. These immunolocalization studies indicate temporal and site-specific expression of myosin Va during chick embryo development, suggesting that myosin Va expression is related to recruitment for specific cellular tasks.

S-100 protein: is it useful as a tumour marker in diagnostic immunocytochemistry

A heterogeneous group of 159 tumours was studied for the presence of S-100 protein by the immunoperoxidase technique in order to determine whether this marker may be of value in facilitating immunocytochemical diagnosis. Among cases of melanocytic and pigmented lesions, S-100 was widely distributed and demonstrated the strongest degrees of reactivity. S-100 protein was identified in virtually all nerve sheath tumours such as schwannomas, neurofibromas, myxoid sheath nerve tumour and also in some tumours of controversial histogenesis such as granular cell tumours. The great majority of carcinomas did not express S-100, with only two cases of breast carcinoma displaying focal S-100 staining. In a miscellaneous group of tumours S-100 was demonstrated in chordomas, myoepitheliomas and Wilms' tumour with Schwann cell differentiation. Despite its presence in a wide array of cell types, S-100 protein continues to be an extremely useful marker especially for soft tissue and peripheral nervous system tumours.

Bone morphogenetic proteins: promising molecules for bone healing, bioengineering, and regenerative medicine

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Genome-wide scan for visceral leishmaniasis in mixed-breed dogs identifies candidate genes involved in T helper cells and macrophage signaling

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Age-Related Expansion of Tim-3 Expressing T Cells in Vertically HIV-1 Infected Children

As perinatally HIV-1-infected children grow into adolescents and young adults, they are increasingly burdened with the long-term consequences of chronic HIV-1 infection, with long-term morbidity due to inadequate immunity. In progressive HIV-1 infection in horizontally infected adults, inflammation, T cell activation, and perturbed T cell differentiation lead to an "immune exhaustion'', with decline in T cell effector functions. T effector cells develop an increased expression of CD57 and loss of CD28, with an increase in co-inhibitory receptors such as PD-1 and Tim-3. Very little is known about HIV-1 induced T cell dysfunction in vertical infection. In two perinatally antiretroviral drug treated HIV-1-infected groups with median ages of 11.2 yr and 18.5 yr, matched for viral load, we found no difference in the proportion of senescent CD28(-)CD57(+)CD8(+) T cells between the groups. However, the frequency of Tim-3(+)CD8(+) and Tim-3(+)CD4(+) exhausted T cells, but not PD-1(+) T cells, was significantly increased in the adolescents with longer duration of infection compared to the children with shorter duration of HIV-1 infection. PD-1(+)CD8(+) T cells were directly associated with T cell immune activation in children. The frequency of Tim-3(+)CD8(+) T cells positively correlated with HIV-1 plasma viral load in the adolescents but not in the children. These data suggest that Tim-3 upregulation was driven by both HIV-1 viral replication and increased age, whereas PD-1 expression is associated with immune activation. These findings also suggest that the Tim-3 immune exhaustion phenotype rather than PD-1 or senescent cells plays an important role in age-related T cell dysfunction in perinatal HIV-1 infection. Targeting Tim-3 may serve as a novel therapeutic approach to improve immune control of virus replication and mitigate age related T cell exhaustion.

The involvement of the spleen during chronic phase of Schistosoma mansoni infection in galectin-3(-/-) mice

Schistosoma mansoni synthesizes glycoconjugates which interact with galectin-3, eliciting an intense humoral immune response. Moreover, it was demonstrated that galectin-3 regulates B cell differentiation into plasma cells. Splenomegaly is a hallmark event characterized by polyclonal B cell activation and enhancement of antibody production. Here, we investigated whether galectin-3 interferes with spleen organization and B cell compartment during chronic schistosomiasis, using wild type (WT) and galectin-3(-/-) mice. In chronically-infected galectin-3(-/-) mice the histological architecture of the spleen, including white and red pulps, was disturbed with heterogeneous lymphoid follicles, an increased number of plasma cells (CD19(-)B220(-/low)CD138(+)) and a reduced number of macrophages (CD19(-)B220(-)Mac-1(+)CD138(-)) and B lymphocytes (CD19(+)B220(+/high)CD138(-)), compared with the WT infected mice. In the absence of galectin-3 there was an increase of annexin-V+PI- cells and a major presence of apoptotic cells in spleen compared with WT infected mice. In spleen of WT infected mice galectin-3 was largely expressed in lymphoid follicles and extrafollicular sites. Thus, we propose that galectin-3 plays a role in splenic architecture, controlling distinct events such as apoptosis, macrophage activity, B cell differentiation and plasmacytogenesis in the course of S. mansoni infection.