Project description:MicroRNAs have been reported to be involved in the regulation of cellular and organismal aging. However, little is known about the role of microRNAs in cardiac aging. We used microarrays to examine microRNA profiles in the hearts from young (8 week-old) and middle-aged (15 month-old) male mice.
Project description:To further analyze the effect of aging and caloric restriction in the microRNA expression, we have employed microarray expression profiling as a discovery platform to identify differentially expressed microRNAs in middle-aged animals and the impact of caloric restriction in the microRNA expression profile. Subcutaneous and visceral adipose tissue were extracted from 3 groups of mice: 3 month-old, 12 month-old fed ad libitum and 12 month-old fed with a caloric restricted diet. Comparisons between young and middle-aged animals in subcutaneous and visceral adipose tissue, and between the 12 month old ad libitum and 12 month old caloric restricted diet in both adipose depots were made.
Project description:We carried out a global survey of age-related changes in mRNA levels in the C57BL/6NIA mouse hippocampus and found a difference in the hippocampal gene expression profile between 2-month-old young mice and 15-month-old middle-aged mice correlated with an age-related cognitive deficit in hippocampal-based explicit memory formation. Middle-aged mice displayed a mild but specific deficit in spatial memory in the Morris water maze. Keywords: age comparison
Project description:We carried out a global survey of age-related changes in mRNA levels in the C57BL/6NIA mouse hippocampus and found a difference in the hippocampal gene expression profile between 2-month-old young mice and 15-month-old middle-aged mice correlated with an age-related cognitive deficit in hippocampal-based explicit memory formation. Middle-aged mice displayed a mild but specific deficit in spatial memory in the Morris water maze. Experiment Overall Design: No technical replicates; 14 biological replicates for 15-month-old mice, 9 biological replicates for 2-month-old mice. Whole hippocampus.
Project description:We sequenced the transcriptome of young (6-8 week) and middle-aged (8-10 month old) C57BL/6 female mice that were naïve or had injured ventrolateral spinal cord white matter. We found several differentially expressed genes, many suggesting an altered immune response to injury with advancing age.
Project description:Senescence-associated alterations in microglia may have profound impact on cerebral homeostasis and stroke outcomes. However, the lack of a transcriptome-wide comparison between young and aged microglia in the context of ischemia limits our understanding of aging-related mechanisms. Herein, we performed bulk RNA sequencing analysis of microglia purified from cerebral hemispheres of young adult (10-week-old) and aged (18-month-old) mice 5 days after distal middle cerebral artery occlusion or sham operation. Considerable transcriptional differences were observed between young and aged microglia in healthy brains, indicating heightened chronic inflammation in aged microglia. Following stroke, the overall transcriptional activation was more robust in young microglia than in aged microglia. Gene clusters with functional implications in immune inflammatory responses, immune cell chemotaxis, tissue remodeling, and cell-cell interactions were markedly activated in microglia of young but not aged stroke mice. These alterations in microglial gene response may contribute to aging-driven vulnerability and poorer recovery after ischemic stroke.
Project description:The thymus is primarily responsible for generating naïve, self-tolerant T cells from hematopoietic precursors. Thymic epithelial cells (TECs) together with other stromal cells create a specialized microenvironment which orchestrates the major selection processes for T cell development. Thymic function progressively deteriorates as part of the aging process, with a dramatic loss in TECs and T cell production, and this ultimately constrains the host immune repertoire. We have previously demonstrated the role of sex steroids in thymic involution in male mice, with surgical castration of middle-aged (9-12 month) male mice resulting in thymus regeneration, peaking around day 28. We have also demonstrated phenotypic alterations in TEC subsets within one week following castration that may contribute to this transient thymus regeneration effect. In this study, we aimed to examine genetic alterations in TEC and non-TEC stromal cell subsets (predominantly fibroblasts and endothelial cells) during age-related thymic involution (5-6 week old young adults compared to 9-12 month middle aged); and genetic changes in TEC and non-TEC at several timepoints following castration, to identify factors that may be involved in thymus regeneration.
Project description:Age-dependent alterations in microglia behavior have been implicated in neurodegeneration and CNS injuries. Here, we compared the transcriptional profiles of young versus aged microglia during stroke recovery. CD45intermediateCD11b+ microglia were FACS-isolated from the brains of young (10-week-old) and aged (18-month-old) male mice 14 days after distal middle cerebral artery occlusion (dMCAO) or sham operation and subjected to RNA-sequencing analysis. Functional groups enriched in young microglia are indicative of upregulation in cell movement, cell interactions, inflammatory responses and angiogenesis, while aged microglia exhibited a reduction or no change in these features. We confirmed reduced chemoattractive capacities of aged microglia toward ischemic brain tissue in organotypic slide co-cultures, and delayed accumulation of aged microglia around dead neurons injected into the striatum in vivo. In addition, aging is associated with an overall failure to increase the expression of microglial genes involved in cell-cell interactions, such as CXCL10. Finally, impaired upregulation of pro-angiogenic genes in aged microglia was associated with a decline in neovascularization in aged mice compared to young mice after dMCAO. This study provides a new resource to understand the mechanisms underlying microglial alterations in the aged brain milieu and sheds light on new strategies to improve microglial functions in aged stroke victims.
Project description:Hearts from young (2-4 month) and moderately aged (16-18 month) C57/Bl6 male mice were subjected to i) 20 min global ischaemia, 60 min reperfusion or ii) 80 min aerobic perfusion/normoxia.
Project description:Label-free quantitative top-down proteomics was performed on mitochondrial lysate isolated from the hearts of 3 young (4-month-old) and 3 old (24-25-month-old) mice.
