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“Heat shock is a well-known stress response characterized by a rapid synthesis of a set of proteins which are responsible for protection against stress. We examined the role of temperature on the growth of cricket paralysis
virus, a member of the family Dicistroviridae, in insect cells. Heat shock caused an induction of heat shock protein-encoding mRNAs in uninfected cells but not in infected cells. While viral RNA and protein were abundant during heat shock, virion formation was inhibited at higher temperatures. The different susceptibility to pathogens at different temperatures is likely a crucial feature of host-pathogen interaction in cold-blooded animals.”
“Hepatitis C virus (HCV)-specific CD8(+) T cells in persistent HCV
LY294002 in vivo infection are low in frequency and paradoxically show a phenotype associated with controlled infections, expressing the memory marker CD127. We addressed to what extent this phenotype is dependent on the presence of cognate antigen. We analyzed virus-specific responses in acute and chronic HCV infections and sequenced autologous virus. We show that CD127 expression is associated with decreased antigenic stimulation after either viral clearance or viral variation. Our data indicate that most CD8 T-cell responses in chronic HCV infection do not target the circulating virus and that the appearance of HCV-specific CD127(+) T cells is driven by viral variation.”
“The purpose of this study was to determine whether ultrastructural
changes in intramyocellular lipid (IMCL) and mitochondria occur with aging. Muscle samples were analyzed from 24 AG-014699 datasheet young and 20 old, equally active, individuals for IMCL and mitochondria quantity and size as well as their association. Old men had larger IMCL droplets than all other groups in the total muscle area. Old individuals almost showed higher IMCL content in the subsarcolemmal area. Young participants had a greater number of mitochondria compared with old participants in both fiber regions and greater enzyme activities of cytochrome c oxidase and citrate synthase. The fraction of IMCL touching mitochondria was lowest in old women in the total area and in old men in the subsarcolemmal region. In summary, older adults have larger IMCL droplets, fewer mitochondria, and a lower proportion of IMCL in contact with mitochondria. These factors likely contribute to age-related reductions in mitochondrial function and lipid metabolism.”
“This study investigated the mechanisms responsible for the disrupted homeostasis of reduced glutathione (GSH) in aging muscles with stress (14 days of hind-limb unloading [HU]). Adult and old rats were randomized into four groups: weight bearing and 3, 7, and 14 days of HU. Soleus muscles were harvested to investigate the activity or content of enzymes involved in GSH metabolism (utilization and synthesis).