Project description:To identify mutations that occurred in the nuclear and mitochondrial DNA of the yeast subjected to mtDNA base editing or Mito-BE screen, we performed whole-genome sequencing of cultured yeast cells after isolation of mitochondrial DNA.
Project description:Purpose: The purpose of this study was to investigate the transcriptomic changes in active Crohn's disease biopsies driven by a mitochondrial-targeted drug (Mito-Tempo)
Project description:Slowing down mRNA translation in either the cytoplasm or the mitochondria are both conserved longevity mechanisms. Here, we found a non-interventional natural correlation of mitochondrial and cytoplasmic ribosomal proteins when looking at mouse population genetics, suggesting a mito-cytoplasmic translational balance. Additionally, inhibiting mitochondrial translation in C. elegans in turn reduced cytoplasmic translation and repressed growth pathways while upregulating stress responses at both proteome and transcriptome levels. This coordinated repression of cytoplasmic translation is dependent on the atf-5/Atf4 transcription factor and is conserved in mammalian cells upon inhibiting mitochondrial translation pharmacologically with the antibiotic doxycycline. Lastly, extending this to a mammalian setting using doxycycline-treated germ-free mice, we found repressed cytoplasmic translation and ribosomal proteins in liver. These data demonstrate that inhibiting mitochondrial translation initiates a signaling cascade leading to coordinated repression of cytoplasmic translation, unlike previously described unidirectional cyto-to-mito translational communication in yeast, which can be targeted to promote healthy aging.
Project description:Extrinsic skin ageing converges on the dermis, a post-mitotic tissue compartment consisting of extracellular matrix and long-lived fibroblasts prone to damage accumulation and maladaptation. Aged human fibroblasts exhibit mitochondrial and nuclear dysfunctions, which may be a cause or consequence of ageing. We report on a systematic study of human dermal fibroblasts retrieved from female donors aged 20-67years and analysed ex vivo at low population doubling precluding replicative senescence. According to gene set enrichment analysis of genome wide array data, the most prominent age-associated change of the transcriptome was decreased expression of mitochondrial genes. Consistent with that, mitochondrial content and cell proliferation declined with donor age. This was associated with upregulation of AMP-dependent protein kinase (AMPK), increased mRNA levels of PPARγ-coactivator 1α (PGC1A) and decreased levels of NAD(+)-dependent deacetylase sirtuin 1. In the old cells the PGC1A-mediated mito-biogenetic response to direct AMPK-stimulation by AICAR was undiminished, while the PGC1A-independent mito-biogenetic response to starvation was attenuated and accompanied by increased ROS-production. In summary, these observations suggest an age-associated decline in PGC1A-independent mito-biogenesis, which is insufficiently compensated by upregulation of the AMPK/PGC1A-axis leading under baseline conditions to decreased mitochondrial content and reductive overload of residual respiratory capacity.
Project description:Extrinsic skin ageing converges on the dermis, a post-mitotic tissue compartment consisting of extracellular matrix and long-lived fibroblasts prone to damage accumulation and maladaptation. Aged human fibroblasts exhibit mitochondrial and nuclear dysfunctions, but it is unclear whether these are cause or consequence of ageing. We report on a systematic study of human dermal fibroblasts retrieved from female donors aged 20-67 years and analyzed in primary culture at low population doubling precluding replicative senescence. Genome-wide array analysis failed to detect significant (>2-fold) age-related expression changes for individual genes, but gene set enrichment analysis revealed down regulation of many genes involved in mitochondrial metabolism and respiratory electron transport, extracellular matrix maintenance, cell cycle progression and protein translation. Consistent with these changes, mitochondrial content, respiratory function and cell proliferation declined with donor age. This was associated with inadequate nuclear mito-biogenesis, hypo- phosphorylation of AMP-dependent protein kinase alpha and upregulation of the alpha2-isoform, suggesting that inadequate mito-nuclear signalling could be the leading event entailing decreased expression of mitochondrial genes and compensatory down regulation of proliferation and protein synthesis. The comparatively few genes exhibiting age-associated up regulation were associate with cholesterol metabolism, immune reactions and mRNA processing, possibly also reflecting adaptation to inadequate mitochondrial function. Donors: 15 human female donors included in the study were aged 20, 21, 23, 26, 26, 40, 41, 42, 43, 49, 60, 62, 63, 64 and 67 years, thus covering the age spectrum 20 – 67 years and providing five biological replicates for each of the age groups “young” (20-30 years), “middle” (40-50 years) and “old” (60-70 years). Human dermal fibroblasts were isolated from skin specimen removed in the course of cosmetic surgery from the bottom side of female breast. Isolation and primary culture of the cells followed published procedures (Tigges and others 2013). Cells were not expanded beyond 12 population doublings, while replicative cell cycle arrest was determined to not occur before 40 population doublings.
Project description:Mito-TAILS N-terminomics analysis of proteolytic events during EPEC infection of human epithelial cells, on whole-cell level and mitochondria.
Project description:To further identity the relationship between neoblast pluripotency and mitochondrial dynamics in cell lineage commitment,single-cell RNA sequencing was used to further analyze the compositions of mito low and mito high cells