Project description:Differentiating pluripotent cells from fibroblast progenitors is a potentially transformative tool in personalized medicine. We previously identified relatively greater success culturing dura-derived fibroblasts than scalp-derived fibroblasts from postmortem tissue. We hypothesized that these differences in culture success were related to epigenetic differences between the cultured fibroblasts by sampling location, and therefore generated genome-wide DNA methylation and transcriptome data on 11 intrinsically matched pairs of dural and scalp fibroblasts from donors across the lifespan (infant to 85 years). While these cultured fibroblasts were several generations removed from the primary tissue and morphologically indistinguishable, we found widespread epigenetic differences by sampling location at the single CpG (N=101,989), region (N=697), “block” (N=243), and global spatial scales suggesting a strong epigenetic memory of original fibroblast location. Furthermore, many of these epigenetic differences manifested in the transcriptome, particularly at the region-level. We further identified 7,265 CpGs and 11 regions showing significant epigenetic memory related to the age of the donor, as well as an overall increased epigenetic variability, preferentially in scalp-derived fibroblasts -83% of loci were more variable in scalp, hypothesized to result from cumulative exposure to environmental stimuli in the primary tissue. By integrating publicly available DNA methylation datasets on individual cell populations in blood and brain, we identified significantly increased inter-individual variability in our scalp- and other skin-derived fibroblasts on a similar scale as epigenetic differences between different lineages of blood cells. Lastly, these epigenetic differences did not appear to be driven by somatic mutation - while we identified 64 probable de-novo variants across the 11 subjects, there was no association between mutation burden and age of the donor (p=0.71). These results depict a strong component of epigenetic memory in cell culture from primary tissue, even after several generations of daughter cells, related to cell state and donor age.
Project description:Differentiating pluripotent cells from fibroblast progenitors is a potentially transformative tool in personalized medicine. We previously identified relatively greater success culturing dura-derived fibroblasts than scalp-derived fibroblasts from postmortem tissue. We hypothesized that these differences in culture success were related to epigenetic differences between the cultured fibroblasts by sampling location, and therefore generated genome-wide DNA methylation and transcriptome data on 11 intrinsically matched pairs of dural and scalp fibroblasts from donors across the lifespan (infant to 85 years). While these cultured fibroblasts were several generations removed from the primary tissue and morphologically indistinguishable, we found widespread epigenetic differences by sampling location at the single CpG (N=101,989), region (N=697), “block” (N=243), and global spatial scales suggesting a strong epigenetic memory of original fibroblast location. Furthermore, many of these epigenetic differences manifested in the transcriptome, particularly at the region-level. We further identified 7,265 CpGs and 11 regions showing significant epigenetic memory related to the age of the donor, as well as an overall increased epigenetic variability, preferentially in scalp-derived fibroblasts -83% of loci were more variable in scalp, hypothesized to result from cumulative exposure to environmental stimuli in the primary tissue. By integrating publicly available DNA methylation datasets on individual cell populations in blood and brain, we identified significantly increased inter-individual variability in our scalp- and other skin-derived fibroblasts on a similar scale as epigenetic differences between different lineages of blood cells. Lastly, these epigenetic differences did not appear to be driven by somatic mutation - while we identified 64 probable de-novo variants across the 11 subjects, there was no association between mutation burden and age of the donor (p=0.71). These results depict a strong component of epigenetic memory in cell culture from primary tissue, even after several generations of daughter cells, related to cell state and donor age.
Project description:Aging signatures developed from a longitudinal study design are dominated by reduced transcription of genes involved in protein synthesis. Aging is a multifactorial process where the impact of singular components still remains unclear. Furthermore, previous studies were focused on measuring specific traits such as DNA -methylation and used categorical group-wise designs, unable to capture intra-individual signature changes. Here we have developed a new method for a longitudinal, age-related analysis combining the merits of a pair-wise design with the statistical power of gene set enrichment analysis. We present an integrated analysis, including transcriptional changes and genome-wide epigenetic changes in DNA- methylation, H3K4- and H3K27- histone methylation in promoter regions. We tested our method on a rare collection of paired skin fibroblast samples from male middle age to old age transitions and obtained functional, age-related clusters. By using a set of only ten individuals, we could demonstrate a high overlap of functional terms to previously established tissue-independent age signatures including extracellular matrix, apoptosis and oxidative stress. Importantly, we identify protein translation-related processes as the main cluster of age-driven, specific down regulation. H3K4me3, H3K27me3 and DNA- methylation longitudinal aging profiles from primary skin fibroblasts from matched pairs of early (E) and late (L) stages in life.
Project description:Aging signatures developed from a longitudinal study design are dominated by reduced transcription of genes involved in protein synthesis Aging is a multifactorial process where the impact of singular components still remains unclear. Furthermore, previous studies were focused on measuring specific traits such as DNA -methylation and used categorical group-wise designs, unable to capture intra-individual signature changes. Here we have developed a new method for a longitudinal, age-related analysis combining the merits of a pair-wise design with the statistical power of gene set enrichment analysis. We present an integrated analysis, including transcriptional changes and genome-wide epigenetic changes in DNA- methylation, H3K4- and H3K27- histone methylation in promoter regions. We tested our method on a rare collection of paired skin fibroblast samples from male middle age to old age transitions and obtained functional, age-related clusters. By using a set of only ten individuals, we could demonstrate a high overlap of functional terms to previously established tissue-independent age signatures including extracellular matrix, apoptosis and oxidative stress. Importantly, we identify protein translation-related processes as the main cluster of age-driven, specific down regulation. Evaluation of transcriptional changes in matched sample pairs of primary skin fibroblasts from middle and old age.
Project description:Reprogramming somatic cells to induced pluripotent stem cells (iPSCs) sets their identity back to an embryonic age. This presents a fundamental hurdle for modeling late-onset disorders using iPSC-derived cells. We therefore developed a strategy to induce age-like features in multiple iPSC-derived lineages and tested its impact on modeling Parkinson’s disease (PD). We first describe markers that predict fibroblast donor age and observed the loss of these age-related markers following iPSC induction and re-differentiation into fibroblasts. Remarkably, age-related markers were readily induced in iPSC-derived fibroblasts or neurons following exposure to progerin including dopamine neuron-specific phenotypes such as neuromelanin accumulation. Induced aging in PD-iPSC-derived dopamine neurons revealed disease phenotypes requiring both aging and genetic susceptibility such as frank dendrite degeneration, progressive loss of tyrosine-hydroxylase expression and enlarged mitochondria or Lewy body-precursor inclusions. Our study presents a strategy for inducing age-related cellular properties and enables the modeling of late-onset disease features. Induced pluripotent stem cell-derived midbrain dopamine neurons from a young and old donor overexpressing either GFP or Progerin.
Project description:In the project “A Dual-Acting Nitric Oxide Donor and Phosphodiesterase 5 Inhibitor Activates Autophagy in Primary Skin Fibroblasts» by Esther Martínez-Martínez and Joern Dengjel, we performed expression proteomics analyzing the response of normal human fibroblasts (NHF) isolated from healthy skin to the drug TOP-N53.
Project description:Genetically matched human iPSCs from different origins were generated using bone marrow stromal cells and dermal fibroblasts of the same donor, and the global gene expression profile were analyzed. Comparison of gene expressions among 14 iPS clones, 4 and 4 were derived from bone marrow stromal cells(BM), 2 and 4 were from dermal skin fibroblasts(SF) of donor90 and 91, respectively.
Project description:Reprogramming somatic cells to induced pluripotent stem cells (iPSCs) sets their identity back to an embryonic age. This presents a fundamental hurdle for modeling late-onset disorders using iPSC-derived cells. We therefore developed a strategy to induce age-like features in multiple iPSC-derived lineages and tested its impact on modeling Parkinson’s disease (PD). We first describe markers that predict fibroblast donor age and observed the loss of these age-related markers following iPSC induction and re-differentiation into fibroblasts. Remarkably, age-related markers were readily induced in iPSC-derived fibroblasts or neurons following exposure to progerin including dopamine neuron-specific phenotypes such as neuromelanin accumulation. Induced aging in PD-iPSC-derived dopamine neurons revealed disease phenotypes requiring both aging and genetic susceptibility such as frank dendrite degeneration, progressive loss of tyrosine-hydroxylase expression and enlarged mitochondria or Lewy body-precursor inclusions. Our study presents a strategy for inducing age-related cellular properties and enables the modeling of late-onset disease features.