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Cultured Cell Line (cultured + cell_line)
Selected AbstractsThe safety of Bacillus subtilis and Bacillus indicus as food probioticsJOURNAL OF APPLIED MICROBIOLOGY, Issue 2 2008H.A. Hong Abstract Aims:, To conduct in vitro and in vivo assessments of the safety of two species of Bacillus, one of which, Bacillus subtilis, is in current use as a food supplement. Methods and Results:, Cultured cell lines, Caco-2, HEp-2 and the mucus-producing HT29-16E cell line, were used to evaluate adhesion, invasion and cytotoxicity. The Natto strain of B. subtilis was shown to be able to invade and lyse cells. Neither species was able to adhere significantly to any cell line. The Natto strain was also shown to form biofilms. No strain produced any of the known Bacillus enterotoxins. Disc-diffusion assays using a panel of antibiotics listed by the European Food Safety Authority (EFSA) showed that only Bacillus indicus carried resistance to clindamycin at a level above the minimum inhibitory concentration breakpoints set by the EFSA. In vivo assessments of acute and chronic dosing in guinea pigs and rabbits were made. No toxicity was observed in animals under these conditions. Conclusions:,Bacillus indicus and B. subtilis should be considered safe for oral use although the resistance of B. indicus to clindamycin requires further study. Significance and Impact of the Study:, The results support the use of B. subtilis and B. indicus strains as food supplements. [source] Antiallergic Activities of Pigmented Rice Bran Extracts in Cell AssaysJOURNAL OF FOOD SCIENCE, Issue 9 2007Sun Phil Choi ABSTRACT:, Using a panel of chemical, biochemical, and cell assays, we determined inhibitory effects of extracts of the pigmented black rice brans on in vitro allergic reactions. Ethanol-water (70% v/v) extracts from 5 pigmented brans were found to be more effective than an extract from a nonpigmented rice cultivar in suppressing the release of histamine and ,-hexosaminidase from basophilic RBL-2H3 cells stimulated with both Ionophore A23187 and immunoglobulin E (IgE)-antigen complexes. Suppression was also obtained with A23187-stimulated rat peritoneal mast cells. The extent of inhibition of these 2 markers of the immune response was accompanied by an influx of calcium ions. The inhibition of the immune process by the pigmented brans was confirmed by the observed modulation of the proinflammatory cytokine gene expressions and cytokine release, as indicated by the reduction in tumor necrosis factor (TNF)-,, interleukin (IL)-1,, IL-4, and IL-6 mRNA expressions determined with the reverse transcription-polymerase chain reaction (RT-PCR). Reduction of TNF-,, IL-1,, and IL-6 protein release from both the cultured cell line and peritoneal cells was further confirmed by enzyme-linked immunoadsorbent assays. Rice bran from the LK1-3-6-12-1-1 cultivar was the most effective inhibitor in all assays. This particular rice variety merits further evaluation as part of a human diet to ascertain its potential to protect against allergic diseases such as hay fever and asthma. [source] Transgenic mouse and cell culture models demonstrate a lack of mechanistic connection between endoplasmic reticulum stress and tau dysfunctionJOURNAL OF NEUROSCIENCE RESEARCH, Issue 9 2010M.L. Spatara Abstract In vivo aggregation of tau protein is a hallmark of many neurodegenerative disorders, including Alzheimer's disease (AD). Recent evidence has also demonstrated activation of the unfolded protein response (UPR), a cellular response to endoplasmic reticulum (ER) stress, in AD, although the role of the UPR in disease pathogenesis is not known. Here, three model systems were used to determine whether a direct mechanistic link could be demonstrated between tau aggregation and the UPR. The first model system used was SH-SY5Y cells, a neuronal cultured cell line that endogenously expresses tau. In this system, the UPR was activated using chemical stressors, tunicamycin and thapsigargin, but no changes in tau expression levels, solubility, or phosphorylation were observed. In the second model system, wild-type 4R tau and P301L tau, a variant with increased aggregation propensity, were heterologously overexpressed in HEK 293 cells. This overexpression did not activate the UPR. The last model system examined here was the PS19 transgenic mouse model. Although PS19 mice, which express the P301S variant of tau, display severe neurodegeneration and formation of tau aggregates, brain tissue samples did not show any activation of the UPR. Taken together, the results from these three model systems suggest that a direct mechanistic link does not exist between tau aggregation and the UPR. © 2010 Wiley-Liss, Inc. [source] Cholangiocytes as immune modulators in rotavirus-induced murine biliary atresiaLIVER INTERNATIONAL, Issue 8 2009Barrett H. Barnes Abstract Background/Aims: Biliary atresia (BA) is a progressive disease characterized by bile duct inflammation and fibrosis. The aetiology is unknown and may be due to a virus-induced, autoimmune-mediated injury of cholangiocytes. Cholangiocytes are not only targets of injury but may also modulate hepatic inflammation. The aim of this study was to determine the immune profile of murine cholangiocytes and the ability to function as antigen-presenting cells (APCs) in culture with Rhesus rotavirus (RRV), poly I:C (viral mimic) or interferon-,/tumour necrosis factor-,. Methods/Results: Both the cholangiocyte cell line (long-term culture) and fresh, ex vivo cholangiocytes expressed APC surface markers major histocompatibility complex (MHC)-class I and II and CD40, while only the cultured cell line expressed costimulatory molecules B7-1 and B7-2. Despite APC expression, cultured cholangiocytes were unable to function as competent APCs in T-cell proliferation assays. Furthermore, both cultured and ex vivo cholangiocytes expressed RNA transcripts for many pro-inflammatory cytokines and chemokines. Conclusions: Although cholangiocytes contain APC molecules, they are incompetent at antigen presentation and cannot elicit effective T-cell activation. Upregulation of MHC-class I and II found in BA mice may serve to prime the cholangiocyte as a target for immune-mediated injury. Cholangiocytes produced many pro-inflammatory cytokines and chemokines in the setting of RRV infection and T-helper type 1 cytokine milieu, suggesting a role of cholangiocytes as immune modulators promoting the ongoing inflammation that exists in RRV-induced BA. [source] Hybrid Lethality in Interspecific F1 Hybrid Nicotiana gossei×N. tabacum Involves a MAP-Kinases Signalling CascadePLANT BIOLOGY, Issue 3 2007M. Mino Abstract: A cultured cell line, GTH4 (Nicotiana gossei Domin ×N. tabacum L.), which exhibits hybrid lethality, died at 26 °C, but not at 37 °C. Pharmacological experiments using inhibitors of protein phosphatases and protein kinases indicated the involvement of a protein kinase signalling pathway in the cell death process. Immunoblot analysis revealed that salicylic acid-induced protein kinase (SIPK) was phosphorylated soon after the shift in temperature from 37 °C to 26 °C. Cultured cells of the hybrid of N. gossei× transgenic N. tabacum harboring a steroid (dexamethasone; DEX)-inducible NtMEK2DD or NtMEK2KR, constitutively active and inactive forms of NtMEK2, respectively, were established. Induction of NtMEK2DD by DEX in the hybrid cells induced the activation of SIPK, the generation of hydrogen peroxide (H2O2), and cell death at 37 °C. The activation of SIPK, generation of H2O2, and cell death at 26 °C were compromised by DEX treatment in hybrid cells harbouring NtMEK2KR. This study provides evidence for the involvement of MAPK signalling in the regulation of cell death in hybrids. [source] Genetic polymorphisms and antiviral activity in the bovine MX1 geneANIMAL GENETICS, Issue 3 2004Y. Nakatsu Summary Bovine MX1 cDNAs consisting of 2280 bp from 11 animals of five breeds and from a cultured cell line were sequenced and compared with previously reported data. Ten nucleotide substitutions were synonymous mutations, and a single nucleotide substitution at 458 resulted in an amino acid exchange of Ile (ATT) and Met (ATG). A 13-bp deletion,insertion mutation was also found in the 3,-UTR. Based on the nucleotide substitutions found in this study, bovine MX1 cDNA was classified into 11 genotypes. A phylogenetic tree of the 11 genotypes suggested that the genotypes observed in Brahman were a great genetic distance from other genotypes. An 18-bp deletion,insertion variation at position 171 was found to be the result of alternative splicing. The 18-bp deletion,insertion is located at the boundary between exon 3 and intron 3. Permanently transfected 3T3 cell lines expressing bovine MX1 mRNA were established to analyse the antiviral potential against VSV,G*-G infection. Transfected cell clones expressing bovine MX1 mRNA showed a significantly smaller number of cells infected with VSV,G*-G compared with the control cells. These results indicate that the bovine MX1 protein has potent antiviral activity. [source] Peptide antibiotic human beta-defensin-1 and ,2 contribute to antimicrobial defense of the intrahepatic biliary treeHEPATOLOGY, Issue 4 2004Kenichi Harada Human beta-defensins (hBDs) are important antimicrobial peptides that contribute to innate immunity at mucosal surfaces. This study was undertaken to investigate the expression of hBD-1 and hBD-2 in intrahepatic biliary epithelial cells in specimens of human liver, and 4 cultured cell lines (2 consisting of biliary epithelial cells and 2 cholangiocarcinoma cells). In addition, hBD-1 and hBD-2 were assayed in specimens of bile. hBD-1 was nonspecifically expressed immunohistochemically in intrahepatic biliary epithelium and hepatocytes in all patients studied, but expression of hBD-2 was restricted to large intrahepatic bile ducts in 8 of 10 patients with extrahepatic biliary obstruction (EBO), 7 of 11 with hepatolithiasis, 1 of 6 with primary biliary cirrhosis (PBC), 1 of 5 with primary sclerosing cholangitis (PSC), 0 of 6 with chronic hepatitis C (CH-C), and 0 of 11 with normal hepatic histology. hBD-2 expression was evident in bile ducts exhibiting active inflammation. Serum C reactive protein levels correlated with biliary epithelial expression of hBD-2. Real-time PCR revealed that in all of 28 specimens of fresh liver, including specimens from patients with hepatolithiasis, PBC, PSC, CH-C and normal hepatic histology, hBD-1 messenger RNA was consistently expressed, whereas hBD-2 messenger RNA was selectively expressed in biliary epithelium of patients with hepatolithiasis. Immunobloting analysis revealed hBD-2 protein in bile in 1 of 3 patients with PSC, 1 of 3 with PBC, and each of 6 with hepatolithiasis; in contrast, hBD-1 was detectable in all bile samples examined. Four cultured biliary epithelial cell lines consistently expressed hBD-1; in contrast these cell lines did not express hBD-2 spontaneously but were induced to express hBD-2 by treatment with Eschericia coli, lipopolysaccharide, interleukin-1, or tumor necrosis factor-,. In conclusion, these findings suggest that in the intrahepatic biliary tree, hBD-2 is expressed in response to local infection and/or active inflammation, whereas hBD-1 may constitute a preexisting component of the biliary antimicrobial defense system. Supplementary material for this article can be found on the Hepatology website (http:/interscience.wley.com/jpages/0270,9139/suppmat/index.html). (Hepatology 2004;40:925-932). [source] Gene expression profiles associated with aging and mortality in humansAGING CELL, Issue 3 2009Richard A. Kerber Summary We investigated the hypothesis that gene expression profiles in cultured cell lines from adults, aged 57,97 years, contain information about the biological age and potential longevity of the donors. We studied 104 unrelated grandparents from 31 Utah CEU (Centre d'Etude du Polymorphisme Humain , Utah) families, for whom lymphoblastoid cell lines were established in the 1980s. Combining publicly available gene expression data from these cell lines, and survival data from the Utah Population Database, we tested the relationship between expression of 2151 always-expressed genes, age, and survival of the donors. Approximately 16% of 2151 expression levels were associated with donor age: 10% decreased in expression with age, and 6% increased with age. Cell division cycle 42 (CDC42) and CORO1A exhibited strong associations both with age at draw and survival after draw (multiple comparisons-adjusted Monte Carlo P -value < 0.05). In general, gene expressions that increased with age were associated with increased mortality. Gene expressions that decreased with age were generally associated with reduced mortality. A multivariate estimate of biological age modeled from expression data was dominated by CDC42 expression, and was a significant predictor of survival after blood draw. A multivariate model of survival as a function of gene expression was dominated by CORO1A expression. This model accounted for approximately 23% of the variation in survival among the CEU grandparents. Some expression levels were negligibly associated with age in this cross-sectional dataset, but strongly associated with inter-individual differences in survival. These observations may lead to new insights regarding the genetic contribution to exceptional longevity. [source] Increased dopamine and its metabolites in SH-SY5Y neuroblastoma cells that express tyrosinaseJOURNAL OF NEUROCHEMISTRY, Issue 2 2003Takafumi Hasegawa Abstract Oxidized metabolites of dopamine, known as dopamine quinone derivatives, are thought to play a pivotal role in the degeneration of dopaminergic neurons. Although such quinone derivatives are usually produced via the autoxidation of catecholamines, tyrosinase, which is a key enzyme in melanin biosynthesis via the production of DOPA and subsequent molecules, may potentially accelerate the induction of catecholamine quinone derivatives by its oxidase activity. In the present study, we developed neuronal cell lines in which the expression of human tyrosinase was inducible. Overexpression of tyrosinase in cultured cell lines resulted in (i) increased intracellular dopamine content; (ii) induction of oxidase activity not only for DOPA but also for dopamine; (iii) formation of melanin pigments in cell soma; and (iv) increased intracellular reactive oxygen species. Interestingly, the expressed tyrosinase protein was initially distributed in the entire cytoplasm and then accumulated to form catecholamine-positive granular structures by 3 days after the induction. The granular structures consisted of numerous rounded, dark bodies of melanin pigments and were largely coincident with the distribution of lysosomes. This cellular model that exhibits increased dopamine production will provide a useful tool for detailed analyses of the potentially noxious effects of oxidized catecholamine metabolites. [source] | |||||||||||||