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dUTP Nick End Labelling (dutp + nick_end_labelling)
Selected AbstractsThe club-shaped gland of amphioxus: export of secretion to the pharynx in pre-metamorphic larvae and apoptosis during metamorphosisACTA ZOOLOGICA, Issue 4 2009Nicholas D. Holland Abstract In amphioxus larvae, the club-shaped gland is a tube connecting the pharyngeal lumen with the external environment. The functions of the gland and its fate during the larva-to-juvenile metamorphosis have long been controversial. Here we use a fixative including ruthenium red to preserve extracellular secretions (presumably glycoproteins) in late pre-metamorphic larvae. This procedure reveals reddish, fibrogranular material in the lumen of the club-shaped gland and in the pharynx adjacent to the gland's inner opening. This finding strengthens the idea that secretions of the club-shaped gland are exported to the pharyngeal lumen to help form a mucous trap for capturing food particles entering the mouth. We also use the terminal desoxynucleotidyl transferase-mediated dUTP nick end labelling (TUNEL) assay to study apoptosis in the tissues of metamorphosing larvae. One of the earliest events of metamorphosis is the massive apoptotic destruction of the club-shaped gland. Therefore, despite some previous opinions to the contrary, the cells of the gland do not survive to participate in the genesis of the definitive endostyle or any other post-larval structures. [source] No change in apoptosis in skeletal muscle exposed acutely or chronically to alcoholADDICTION BIOLOGY, Issue 1 2003AG PAICE The pathogenic mechanisms responsible for the deleterious changes in ethanol-exposed skeletal muscle are unknown, although apoptosis may be a causal process. We therefore investigated the responses of skeletal muscle to acute or chronic ethanol exposure in male Wistar rats. In acute studies, rats were dosed with ethanol (75 mmol (3.46 g)/kg BW) and killed after either 2.5 or 6 hours. In chronic studies, rats were fed ethanol as 35% of total dietary energy for 6 weeks. Apoptosis was determined by either DNA fragmentation or TUNEL (terminal deoxynucleotidyl transferase mediated dUTP nick end labelling) assays. The results showed that apoptosis was not increased in the ethanol-exposed muscle in both acute and chronic studies compared to appropriate controls. [source] Evidence for a perforin-mediated mechanism controlling cardiac inflammation in Trypanosoma cruzi infectionINTERNATIONAL JOURNAL OF EXPERIMENTAL PATHOLOGY, Issue 2 2002ANDREA HENRIQUES-PONS Summary. ,CD8+ T lymphocytes are considered an important cell population involved in the control of parasitaemia and mortality after Trypanosoma cruzi infection. However, despite recent developments in this field, the mechanism whereby this control is exerted is still not completely understood. Here we have used perforin knockout (,/,) mice infected with Y strain T. cruzi in order to evaluate specifically the participation of the perforin-based cytotoxic pathway in the destruction of cardiomyocytes, cellular inflammatory infiltration, and control of parasitaemia and mortality. We observed that although parasitaemia was equivalent in perforin (+/+) and (,/,) groups, survival rate and spontaneous physical performance were significantly lower in the perforin deficient mice. The cardiac inflammatory cell infiltration, mostly composed of CD8+ cells, was more evident in perforin (,/,) mice. Ultrastructural and immunofluorescence analysis, as well as plasma creatine kinase activity, revealed cardiomyocyte damage and necrosis, more evident in perforin (,/,) mice. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling (TUNEL) assays performed in heart samples revealed similar and modest levels of apoptosis in both perforin (+/+) and (,/,) mice. These results indicate that perforin does not play a pivotal role in the control of parasitaemia and direct lysis of cardiomyocytes, but seems to be an important molecule involved in the control of cardiac inflammation and pathology induced by a highly virulent strain of T. cruzi. [source] Apoptosis is associated with CD36/fatty acid translocase upregulation in non-alcoholic steatohepatitisLIVER INTERNATIONAL, Issue 6 2010Lars P. Bechmann Abstract Background & aims: Hepatocyte apoptosis is a key event in non-alcoholic steatohepatitis (NASH). We studied the effect of obesity on free fatty acid (FFA) levels, fatty acid transport proteins (FATPs) and on extrinsic and intrinsic activation of apoptosis in the liver. Methods: Liver biopsies were harvested from 52 morbidly obese patients [body mass index (BMI): 53.82±1.41; age: 45±10.50; 15 males/37 females] undergoing bariatric surgery, and were scored for NASH, evaluated for fibrosis, and investigated for intrahepatic expression of FATPs, death receptors and cytosolic apoptosis-related molecules. Findings were correlated with serum FFA levels and the degrees of intrahepatic (terminal dUTP nick end labelling) and systemic (M30) apoptosis. Results: In patients' liver sections, FATPs as well as select parameters of extrinsic and intrinsic apoptosis were found to be upregulated (CD36/FAT: × 11.56; FATP-5: × 1.33; CD95/Fas: × 3.18; NOXA: × 2.79). These findings correlated with significantly elevated serum FFAs (control: 14.72±2.32 mg/dl vs. patients: 23.03±1.24 mg/dl) and M30 levels (control: 83.12±7.46 U/L vs. patients: 212.61±22.16 U/L). We found correlations between FATPs and apoptosis mediators as well as with histological criteria of NASH and fibrosis. Conclusions: Increased FFA and FATPs are associated with extrinsically and intrinsically induced apoptosis, liver damage and fibrosis in obese patients. Thus, FATPs may offer an interesting new approach to understand and potentially intervene NASH pathogenesis. [source] Expression Pattern of Apoptotic Genes in Vitrified-Thawed Bovine OocytesREPRODUCTION IN DOMESTIC ANIMALS, Issue 5 2010VM Anchamparuthy Contents This study describes a method for quantification of transcripts from low numbers of bovine oocytes using real time RT-PCR. The objective was to evaluate the expression pattern of apoptotic genes (Fas, FasL, Bax and Bcl-2) in vitrified-thawed oocytes. Oocytes were evaluated at germinal vesicle stage; at 15 h of maturation; after vitrification and warming at 15 h of maturation and at 9 h of additional maturation. All transcripts showed an increase in at least 1.2-fold change post-vitrification warming, but the levels tended to decrease at 9 h of maturation post-vitrification warming. Transcript abundance for Fas mRNA was 1.4-fold for oocytes after vitrification and warming. The level of Fas mRNA upon maturation was 0.8-fold. The increase in the abundance of FasL mRNA was 2.1, while it was 0.5-fold relative to control. Vitrification resulted in 1.5-fold change in Bax mRNA expression in oocytes. After 9 h of maturation post-vitrification warming, the level for Bax mRNA was 0.6-fold. The mRNA for Bcl-2 was nearly the same after vitrification and warming. The abundance of mRNA for Bcl-2 was 1.2-fold in vitrified oocytes and fell (p = 0.05) to 0.5 at 9 h of maturation post-vitrification and warming. The up-regulation of apoptotic genes in vitrified oocytes may be an early indicator of reduced developmental competence following vitrification. Yet, results from terminal deoxynucleotidyl transferase dUTP nick end labelling and caspase assays did not support the evidence of apoptosis in embryos derived from large numbers of vitrified oocytes. [source] Haematopoietic antigen-presenting cells in the human thymic cortex: evidence for a role in selection and removal of apoptotic thymocytes,THE JOURNAL OF PATHOLOGY, Issue 1 2008LC Paessens Abstract Only a small proportion of thymocytes survive T cell selection in the thymus and leave the thymus as mature T cells. The vast majority of thymocytes undergo cell death during selection, either due to failure to undergo positive selection on self peptide-MHC presented by thymic antigen presenting cells (APC) or due to negative selection. In the murine thymus it has been shown that most thymocytes that fail selection undergo apoptosis in the thymic cortex and are removed by cortical macrophages. However, it is unknown how apoptotic thymocytes are cleared from the cortex of the human thymus. Here we report the identification of antigen-presenting cells of haematopoietic origin (hAPCs) by expression of dendritic cell (DC) specific C-type lectin DC-SIGN (CD209) in the cortex of the human thymus, and show that these cells exhibit features of both immature DCs and macrophages. The analysis of cellular markers, in particular the expression of the molecular chaperone HLA-DM, on cortical hAPCs further suggests that these hAPCs may participate in selection of thymocytes in the cortex. Using in situ terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL), we demonstrated that these cortical hAPCs are surrounded by apoptotic, TUNEL+ thymocytes in situ. Futhermore, in situ immuno-cryo-electron microscopy suggests that cortical hAPCs take up and remove apoptotic thymocytes. Thus, DC-SIGN+ hAPCs in the human thymic cortex appear to function in thymocyte selection and removal of apoptotic thymocytes from the thymic cortex. Copyright © 2007 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. [source] Influence of Hyperglycaemia on Chemical-Induced Toxicity: Study with Cyclophosphamide in RatBASIC AND CLINICAL PHARMACOLOGY & TOXICOLOGY, Issue 4 2009Kalavatala Saandeep Hyperglycaemia perturbs the critical balance between oxidative stress and anti-oxidant defence mechanisms in the body and thereby alters the response of biological system towards various toxic chemicals. Cyclophosphamide (CP) is a widely prescribed anticancer drug, well-known genotoxic agent as well as used in the development of immunocompromised animal models. The present study investigated the modulating effect of diabetes on the cyclophosphamide-induced cytotoxicity and genotoxicity. The study was performed on male Sprague-Dawley rats (200 ± 10 g). Cyclophosphamide (10 mg/kg) was administered five consecutive days in a week for 3 weeks to both control and diabetic rats. Thiobarbituric acid reactive substances (TBARS) levels were measured in the plasma, liver, kidney and lung tissues. DNA damaging potential of cyclophosphamide under diabetic condition was evaluated using comet and halo assay as an endpoint. To further ascertain the mode of cell death, terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling (TUNEL) assay and immunohistochemical evaluation of p53 was performed. Significant increase in DNA damage was revealed by the comet assay parameters, halo assay indicated the level of cytotoxicity and the oxidative stress was measured using the TBARS assay in the diabetic rats receiving cyclophosphamide treatment. The toxic effects were more prominent in diabetic animals as compared to non-diabetic rats. Cyclophosphamide treatment and diabetic condition per se led to increase in the p53 + and TUNEL + cells in the liver and kidney of rats. Under diabetic condition, further increase in the p53 + and TUNEL + cells was observed in response to cyclophosphamide. In the present study, we report that hyperglycaemic condition exaggerates the cyclophosphamide-induced toxicity and the response was found to be tissue specific. [source] | |||||||||||||