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11.
Ly Diane Dongol Anjila Cuthbertson Peter Guy Thomas V. Geraghty Nicholas J. Sophocleous Reece A. Sin Lucia Turner Bradley J. Watson Debbie Yerbury Justin J. Sluyter Ronald 《Purinergic signalling》2020,16(1):109-122
Purinergic Signalling - The ATP-gated P2X7 ion channel has emerging roles in amyotrophic lateral sclerosis (ALS) progression. Pharmacological blockade of P2X7 with Brilliant Blue G can ameliorate... 相似文献
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Daan K. J. Pieren Noortje A. M. Smits Jeroen Hoeboer Vinitha Kandiah Rimke J. Postel Rob Mariman Josine van Beek Debbie van Baarle Jelle de Wit Teun Guichelaar 《Aging cell》2021,20(6)
Severe respiratory viral infectious diseases such as influenza and COVID‐19 especially affect the older population. This is partly ascribed to diminished CD8+ T‐cell responses a result of aging. The phenotypical diversity of the CD8+ T‐cell population has made it difficult to identify the impact of aging on CD8+ T‐cell subsets associated with diminished CD8+ T‐cell responses. Here we identify a novel human CD8+ T‐cell subset characterized by expression of Killer‐cell Immunoglobulin‐like Receptors (KIR+) and CD45RA (RA+). These KIR+RA+ T cells accumulated with age in the blood of healthy individuals (20–82 years of age, n = 50), expressed high levels of aging‐related markers of T‐cell regulation, and were functionally capable of suppressing proliferation of other CD8+ T cells. Moreover, KIR+RA+ T cells were a major T‐cell subset becoming activated in older adults suffering from an acute respiratory viral infection (n = 36), including coronavirus and influenza virus infection. In addition, older adults with influenza A infection showed that higher activation status of their KIR+RA+ T cells associated with longer duration of respiratory symptoms. Together, our data indicate that KIR+RA+ T cells are a unique human T‐cell subset with regulatory properties that may explain susceptibility to viral respiratory disease at old age. 相似文献
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Stephanie Moormann Debbie Guatelli‐Steinberg John Hunter 《American journal of physical anthropology》2013,150(3):400-408
The patterning cascade model of tooth morphogenesis has emerged as a useful tool in explaining how tooth shape develops and how tooth evolution may occur. Enamel knots, specialized areas of dental epithelium where cusps initiate, act as signaling centers that direct the growth of surrounding tissues. For a new cusp to form, an enamel knot must form beyond the inhibition fields of other enamel knots. The model predicts that the number and size of cusps depends on the spacing between enamel knots, reflected in the spacing between cusps. Recently, work by our group demonstrated that the model predicted Carabelli trait expression in human first molars. Here we test whether differences in Carabelli trait expression along the molar row can also be predicted by the model. Crown areas and intercusp distances were measured from dental casts of 316 individuals with a digital microscope. Although absolute cusp spacing is similar in first and second molars, the smaller size and more triangular shape of second molars results in larger cusp spacing relative to size and, likely, less opportunity for the Carabelli trait to form. The presence and size of the hypocone (HY) and a range of small accessory cusps in a larger sample of 340 individuals were also found to covary with the Carabelli trait in a complex way. The results of this study lend further support to the view that the dentition develops, varies, and evolves as a single functional complex. Am J Phys Anthropol, 2013. © 2013 Wiley Periodicals, Inc. 相似文献
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Mohammed Sherif Debbie Waung Bihter Korbeci Valentina Mavisakalyan Robert Flick Greg Brown Mamdouh Abou‐Zaid Alexander F. Yakunin Emma R. Master 《Microbial biotechnology》2013,6(5):588-597
Multicopper oxidases can act on a broad spectrum of phenolic and non‐phenolic compounds. These enzymes include laccases, which are widely distributed in plants and fungi, and were more recently identified in bacteria. Here, we present the results of biochemical and mutational studies of small laccase (SLAC), a multicopper oxidase from Streptomyces coelicolor (SCO6712). In addition to typical laccase substrates, SLAC was tested using phenolic compounds that exhibit antioxidant activity. SLAC showed oxidase activity against 12 of 23 substrates tested, including caffeic acid, ferulic acid, resveratrol, quercetin, morin, kaempferol and myricetin. The kinetic parameters of SLAC were determined for 2,2′‐azino‐bis(3‐ethylbenzthiazoline‐6‐sulphonic acid), 2,6‐dimethoxyphenol, quercetin, morin and myricetin, and maximum reaction rates were observed with myricetin, where kcat and Km values at 60°C were 8.1 (± 0.8) s?1 and 0.9 (± 0.3) mM respectively. SLAC had a broad pH optimum for activity (between pH 4 and 8) and temperature optimum at 60–70°C. It demonstrated remarkable thermostability with a half‐life of over 10 h at 80°C and over 7 h at 90°C. Site‐directed mutagenesis revealed 17 amino acid residues important for SLAC activity including the 10 His residues involved in copper coordination. Most notably, the Y229A and Y230A mutant proteins showed over 10‐fold increase in activity compared with the wild‐type SLAC, which was correlated to higher copper incorporation, while kinetic analyses with S929A predicts localization of this residue near the meta‐position of aromatic substrates. 相似文献
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Mohammad Nasif Sarowar Albert Hendrik van den Berg Debbie McLaggan Mark R. Young Pieter van West 《Fungal biology》2013,117(11-12):752-763
Saprolegnia species are destructive pathogens to many aquatic organisms and are found in most parts of the world. Reports based on phylogenetic analysis suggest that Saprolegnia strains isolated from aquatic animals such as crustaceans and frogs are close to Saprolegnia strains isolated from infected fish or fish eggs and vice versa. However, it has often been assumed that host specificity occurs for each individual isolate or strain. Here we demonstrate that Saprolegnia spp. can have multiple hosts and are thus capable of infecting different aquatic organisms. Saprolegnia delica, Saprolegnia hypogyna, and 2 strains of Saprolegnia diclina were isolated from aquatic insects and amphipods while S. delica, Saprolegnia ferax, Pythium pachycaule, and a Pythium sp. were isolated from the water of a medium to fast flowing river. The ITS region of the rRNA gene was sequenced for all isolates. In challenge experiments, all four isolates from insects were found to be highly pathogenic to eggs of Atlantic salmon (Salmo salar) and embryos of the African clawed frog (Xenopus laevis). We found that Saprolegnia spp. isolated from salmon eggs were also able to successfully establish infection in nymphs of stonefly (Perla bipunctata) and embryos of X. laevis). These results suggest that Saprolegnia spp. are capable of infecting multiple hosts, which may give them an advantage during seasonal variation in their natural environments. 相似文献