title: Underexpression of mitochondrial-DNA encoded ATP synthesis-related genes and DNA repair genes in systemic lupus erythematosus.
abstract: BACKGROUND
  Systemic lupus erythematosus (SLE) is a prototypical autoimmune disease characterized by various systemic symptoms and multiple organ damage. We clarify biological and functional abnormalities in SLE by comparing the gene expression profiles of SLE patients with those of healthy individuals.
  
  
  METHODS
  Gene expression profiles from the peripheral blood of 21 SLE patients and 45 healthy individuals were obtained using a DNA microarray. Gene ontology analysis and network pathway analysis were performed on the genes differentially expressed between SLE and healthy individuals.
  
  
  RESULTS
  A total of 2,329 upregulated genes and 1,884 downregulated genes were differentially expressed. Gene ontology analysis revealed that the upregulated genes were classified as response to biotic stimulus genes, which mainly includes genes related to immune response. Abnormalities in other categories such as cell motility and regulation of apoptosis were also revealed. Downregulated genes were mainly sorted into two gene categories, sensory perception and response to radiation/light. The sensory perception genes included ATPase/ATPase domain-containing genes, myosin-related genes, and two excision repair cross-complementing genes, which are involved in DNA repair. Other genes in this group--including three crystallin genes, genes encoding the receptor protein for melanocyte-stimulating hormone, and six mitochondrial-DNA encoded genes, which are involved in ATP synthesis--were also categorized as response to radiation genes. Using network pathway analysis, IL-6, transforming growth factor beta 1, TNF, and hepatocyte nuclear factor 4α were found to play central roles in the networks of sensory perception-related molecules.
  
  
  CONCLUSIONS
  Functional abnormalities in ATP synthesis and DNA repair are implicated in peripheral blood cells from SLE patients.
authors.affiliation: Graduate School of Frontier Biosciences, Osaka University, 1-3 Yamada-Oka, Suita, Osaka 565-0871, Japan.
authors.forename: Hooi-Ming
authors.initials: HM
authors.lastname: Lee
authors.forename: Hidehiko
authors.initials: H
authors.lastname: Sugino
authors.forename: Chieko
authors.initials: C
authors.lastname: Aoki
authors.forename: Norihiro
authors.initials: N
authors.lastname: Nishimoto
mesh_terms: D000255:Adenosine Triphosphate / Q000096:biosynthesis*; D000328:Adult; D000368:Aged; D004260:DNA Repair / Q000235:genetics*; D004272:DNA, Mitochondrial / Q000235:genetics*; D015536:Down-Regulation; D005260:Female; D020869:Gene Expression Profiling; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000235:genetics*; D008875:Middle Aged; D020411:Oligonucleotide Array Sequence Analysis
chemical_list: D004272:DNA, Mitochondrial; D000255:Adenosine Triphosphate