Dataset Information

Altered MCM protein levels and autophagic flux in aged and systemic sclerosis dermal fibroblasts.

ABSTRACT: Aging is a common risk factor of many disorders. With age, the level of insoluble extracellular matrix increases leading to increased stiffness of a number of tissues. Matrix accumulation can also be observed in fibrotic disorders, such as systemic sclerosis (SSc). Although the intrinsic aging process in skin is phenotypically distinct from SSc, here we demonstrate similar behavior of aged and SSc skin fibroblasts in culture. We have used quantitative proteomics to characterize the phenotype of dermal fibroblasts from healthy subjects of various ages and from patients with SSc. Our results demonstrate that proteins involved in DNA and RNA processing decrease with age and in SSc, whereas those involved in mitochondrial and other metabolic processes behave the opposite. Specifically, minichromosome maintenance (MCM) helicase proteins are less abundant with age and SSc, and they exhibit an altered subcellular distribution. We observed that lower levels of MCM7 correlate with reduced cell proliferation, lower autophagic capacity, and higher intracellular protein abundance phenotypes of aged and SSc cells. In addition, we show that SSc fibroblasts exhibit higher levels of senescence compared with their healthy counterparts, suggesting further similarities between the fibrotic disorder and the aging process. Hence, at the molecular level, SSc fibroblasts exhibit intrinsic characteristics of fibroblasts from aged skin.

SUBMITTER: Dumit VI

PROVIDER: S-EPMC4121389 | biostudies-literature | 2014 Sep

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Altered MCM protein levels and autophagic flux in aged and systemic sclerosis dermal fibroblasts.

Dumit Verónica I VI Küttner Victoria V Käppler Jakob J Piera-Velazquez Sonsoles S Jimenez Sergio A SA Bruckner-Tuderman Leena L Uitto Jouni J Dengjel Jörn J

The Journal of investigative dermatology 20140204 9

Aging is a common risk factor of many disorders. With age, the level of insoluble extracellular matrix increases leading to increased stiffness of a number of tissues. Matrix accumulation can also be observed in fibrotic disorders, such as systemic sclerosis (SSc). Although the intrinsic aging process in skin is phenotypically distinct from SSc, here we demonstrate similar behavior of aged and SSc skin fibroblasts in culture. We have used quantitative proteomics to characterize the phenotype of ...[more]

PMID: 24496236

Similar Datasets

Project description:Systemic sclerosis (SSc) is characterized by severe and often progressive fibrosis of the skin and multiple internal organs. The mechanisms responsible for these alterations remain obscure, although excessive reactive oxygen species (ROS)-mediated oxidative stress has been implicated. NOX-4 is 1 of 7 isoforms of NADPH oxidase responsible for the generation of ROS. The purpose of this study was to examine NOX-4 expression in skin and cultured dermal fibroblasts from SSc patients and to examine its regulation by transforming growth factor ?1 (TGF?1).NOX-4 was assessed in normal and SSc skin by immunohistologic analysis and in normal and SSc cultured dermal fibroblasts by quantitative polymerase chain reaction analysis, fluorescence microscopy, and Western blotting. ROS levels were assessed by fluorescence measurement of H2 O2 production. Specific kinase inhibitors were used to study the TGF?1 signaling involved in NOX-4 stimulation. NOX-4 inhibition/down-regulation was induced with a selective NOX-4 small-molecule inhibitor and NOX-4 small interfering RNA (siRNA).In contrast with normal skin fibroblasts, those from SSc skin showed intense NOX-4 staining. Cultured SSc fibroblasts displayed increased NOX-4 expression. TGF?1 caused potent NOX-4 protein and messenger RNA stimulation in normal and SSc fibroblasts, which was mediated by the protein kinase C? (PKC?) and Smad2/3 pathways. NOX-4 knockdown in SSc fibroblasts reduced the production of ROS and lowered the expression of type I collagen.NOX-4 expression and production were found to be constitutively elevated in SSc skin and cultured SSc dermal fibroblasts. TGF?1 stimulated NOX-4 expression in normal and SSc fibroblasts through PKC? and Smad2/3 signaling pathways. A small-molecule NOX-4 inhibitor decreased collagen and fibronectin production by normal and SSc fibroblasts, and NOX-4 siRNA knockdown reduced ROS and collagen production by SSc fibroblasts. These results demonstrate the involvement of NOX-4 in SSc-associated fibrosis and indicate NOX-4 inhibitors as novel therapeutic approaches for SSc.

Project description:Background. The etiology and reasons underlying the ethnic disparities in systemic sclerosis (SSc) remain unknown. African-Americans (AA) are disproportionally affected by SSc, yet dramatically underrepresented in research. The role of DNA methylation in disease risk remains unclear. This analysis was conducted to comprehensive identify differentially methylated loci associated with SSc in AA. Methods. Genomic DNA was isolated from cultured dermal fibroblasts isolated from 15 AA SSc cases and 15 AA controls. All patients met the 2013 ACR/EULAR classification criteria for SSc, most (93%) presenting with diffuse cutaneous SSc. DNA methylation patterns were profiled through reduced representation bisulfite sequencing (RRBS). Alignment and methylation calling were performed using Bismarck v0.16.3 and the GRCh37/hg19 reference genome. Data was filtered, normalized, and analyzed with RnBeads v1.6.1. Differential methylation analysis was conducted on CpG, promoter, gene and system level. Results. We generated DNA methylation data for over 5 million CpGs in each sample and between 10x to 40x coverage in CpGs sites. Using the Combined Score approach implemented in RnBeads, a total of 9 CpG islands, 17 genes and 11 promoters showed significant differential methylation levels between cases and controls at the gene-level. The top differentially methylated genes constitute mostly non-coding RNA genes (42%), followed by pseudogenes (27%), then protein coding genes (19%). Enrichment analysis revealed that both hypo- and hypermethylated genes and their promoter regions were enriched for cell differentiation and immune-related gene ontology terms (hypermethylated regions: mesenchymal cell transition and differentiation; hypomethylated regions: type I IFN signaling). Conclusion. The observed DNA methylation differences between cases and controls support a modest role for DNA methylation differences in mediating susceptibility to SSc in AA. Instead of protein-coding, most differentially methylated genes comprise non-coding RNA genes, supporting a larger contribution of dysregulated regulatory elements to disease. While previous DNA methylation profiling analyses in European-Americans reported an enrichment of extracellular matrix and focal adhesion genes, our data supports a potentially stronger immune-driven etiology in AA.

Dataset Information

Altered MCM protein levels and autophagic flux in aged and systemic sclerosis dermal fibroblasts.

Publications

Altered MCM protein levels and autophagic flux in aged and systemic sclerosis dermal fibroblasts.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets