Project description:Platelets were isolated from standard-housed and exercising (4 days and 28 days) 18-month-old C57BL/6J mice and mass spectrometry performed. This analysis revealed differential proteomic signatures between platelets from exercsising and standard-housed mice.
Project description:We have reported previously that when chromosome Y (chrY) from the mouse strain C57BL/6J (abbreviated as B) was substituted for that of A/J mice (ChrY<A>), cardiomyocytes from the resulting 'chromosome substitution' C57BL/6J-chrY<A> strain (abbreviated as B.Y) were smaller than that of their C57BL/6J counterparts. In reverse, when chrY<A> from A/J mice was substituted for that of chrY<B>, cardiomyocytes from the resulting A/J-chrY<C57> strain were larger than in their A/J counterparts. We further used these strains (B and the consomic B.Y) to test whether the origin of chrY could also be linked to differences in the profile of gene expression in their cardiac left ventricles in adult mice where either sham surgery (intact animals) or castration has been performed at 3-4 weeks of age..
Project description:We report RNA-seq of skeletal muscle (quadriceps) of young (6-month), old (24-month), and senolytic (Dasatinib + quercetin) treated mice
Project description:We investigated age-related changes in the transcriptional profile of skeletal muscle in 5 month old (young) and 25 month old (old) C57BL/6NHsd mice using high density oligonucleotide arrays (22,690 transcripts probed). We identified 712 transcripts that are differentially expressed in young (5 month old) and old (25-month old) mouse skeletal muscle. Caloric restriction (CR) completely or partially reversed 87% of the changes in expression. Examination of individual genes revealed a transcriptional profile indicative of increased p53 activity in the older muscle. To determine whether the increase in p53 activity is associated with transcriptional activation of apoptotic targets, we performed RT-PCR on four well known mediators of p53-induced apoptosis: puma, noxa, tnfrsf10b and bok. Expression levels for these proapoptotic genes increased significantly with age (P<0.05), while CR significantly lowered expression levels for these genes as compared to control fed old mice (P<0.05). Age-related induction of p53-related genes was observed in multiple tissues, but was not observed in SOD2+/- and GPX4+/- mice, suggesting that oxidative stress does not mediate the observed age-related increase in expression. Western blot analysis confirmed that protein levels for both p21 and GADD45a, two established transcriptional targets of p53, were higher in the older muscle tissue. These observations support a role for p53-mediated apoptotic activity in mammalian aging. Keywords: aging, calorie restriction, muscle, p53
Project description:We have reported previously that when chromosome Y (chrY) from the mouse strain C57BL/6J (abbreviated as B) was substituted for that of A/J mice (ChrY<A>), cardiomyocytes from the resulting 'chromosome substitution' C57BL/6J-chrY<A> strain (abbreviated as B.Y) were smaller than that of their C57BL/6J counterparts. In reverse, when chrY<A> from A/J mice was substituted for that of chrY<B>, cardiomyocytes from the resulting A/J-chrY<C57> strain were larger than in their A/J counterparts. We further used these strains (B and the consomic B.Y) to test whether the origin of chrY could also be linked to differences in the profile of gene expression in their cardiac left ventricles in adult mice where either sham surgery (intact animals) or castration has been performed at 3-4 weeks of age.. Samples from 4 different mice were used in each group. For hybridization, probes generated from samples were randomized on 2 different Illumina MouseRef v2.0 BeadChips.
Project description:We investigated age-related changes in the transcriptional profile of skeletal muscle in 5 month old (young) and 25 month old (old) C57BL/6NHsd mice using high density oligonucleotide arrays (22,690 transcripts probed). We identified 712 transcripts that are differentially expressed in young (5 month old) and old (25-month old) mouse skeletal muscle. Caloric restriction (CR) completely or partially reversed 87% of the changes in expression. Examination of individual genes revealed a transcriptional profile indicative of increased p53 activity in the older muscle. To determine whether the increase in p53 activity is associated with transcriptional activation of apoptotic targets, we performed RT-PCR on four well known mediators of p53-induced apoptosis: puma, noxa, tnfrsf10b and bok. Expression levels for these proapoptotic genes increased significantly with age (P<0.05), while CR significantly lowered expression levels for these genes as compared to control fed old mice (P<0.05). Age-related induction of p53-related genes was observed in multiple tissues, but was not observed in SOD2+/- and GPX4+/- mice, suggesting that oxidative stress does not mediate the observed age-related increase in expression. Western blot analysis confirmed that protein levels for both p21 and GADD45a, two established transcriptional targets of p53, were higher in the older muscle tissue. These observations support a role for p53-mediated apoptotic activity in mammalian aging. Experiment Overall Design: Animals were killed by cervical dislocation. Five different animals were used for each experimental group. All collected gastrocnemius tissue was then dissected, placed in a microcentrifuge tube, flash-frozen in liquid nitrogen, and stored at -80°C until processed for microarrays.
Project description:We report RNA sequencing data from the infraspinatus muscles of 3-month old male C57BL/6J (Jackson Labs stock 000664) or MRL/MpJ mice (Jackson Labs stock 000486). Mice underwent a full-thickness infraspinatus tenectomy and denervation, and four weeks later muscles were collected for analysis. Comparisons are made to control male mice of the same strains who did not undergo infraspinatus tenectomy and denervation.
Project description:Aging is associated with systemic chronic inflammation (inflammaging) that leads to impaired physiological functions and vulnerability to several diseases. However, underlying alterations in aged immune system resulting in gradual loss of immune fitness remain unclear. Using a combination of CD8 T cell transfer from young to old and from old to young mice and single-cell RNA sequencing, we characterized the age-associated alterations in CD8 T cells. We transferred 2 millions of purified CD8+ T cells pooled from 3 CD45.1 C57BL/6J 3 months old female mice (donor) by i.v. injection into CD45.2 C57BL/6J 24 months old female mouse (recipient) and sorted CD45.1+CD3e+CD8a+ and CD45.2+CD3e+CD8a+ T cells from the spleen 1 month post transfer to perform scRNA/TCR-seq.
Project description:The ability to generate defined null mutations in mice revolutionized the analysis of gene function in mammals. However, gene-deficient mice generated by using 129-derived embryonic stem (ES) cells may carry large segments of 129 DNA, even when extensively backcrossed to reference strains, such as C57BL/6J, and this may confound interpretation of experiments performed in these mice. Tissue plasminogen activator (tPA), encoded by the PLAT gene, is a fibrinolytic serine protease that is widely expressed in the brain. A large number of neurological abnormalities have been reported in tPA-deficient mice. The studies here compare genes differentially expressed in the brains of Plat-/- mice from two independent Plat-/- mouse derivations to wild-type C57BL/6J mice. One strain denoted “Old” was constructed in ES cells from a 129 mouse and backcrossed extensively to C57BL/6J, and one denoted “New” Plat-/- mouse was constructed using zinc finger nucleases directly in the C57BL/6J-Plat-/- mouse strain. We identify a significant set of genes that are differentially expressed in the brains of Old Plat-/- mice that preferentially cluster in the vicinity of Plat on chromosome 8, apparently linked to more than 20 Mbp of DNA flanking Plat being of 129 origin. No such clustering is seen in the New Plat-/- mice.
Project description:Pofut1 is an essential gene that glycosylates proteins containing EGF-like repeats, including Notch Receptors (NotchRs). Work in mice and in Drosophila has shown that O-fucosylation by Pofut1 is required for NotchR ligands to bind to and activate NotchRs. As such, Pofut1 deletion in skeletal myofibers allows for an analysis of potential functions and molecular changes of Pofut1 in skeletal muscle that derive from its expression in skeletal myofibers. In this study we compared gene expression profiles between quadriceps muscles in young (2 month) and old (17 month) mice where Protein O-fucosyltransferase 1 (Pofut1) was deleted specifically in skeletal myofibers via use of a human skeletal alpha actin Cre transgene (Scre) and a loxP flanked Pofut1 gene (SCreFF) and mice which bore the only the Scre transgene but did not have floxed Pofut1 alleles (SCre++).