(i) DNA extracted from peripheral blood lymphocytes
(i) SLE patients (ii) Healthy individuals
(i) Polymorphism analysis of a single-nucleotide rs1799782 (Arg > Trp codon 194) and rs25487 (Arg > Gln codon 399) of the XRCC1 gene by PCR-RFLP.
(i) Increased frequency of Arg > Gln polymorphism 399 in SLE patients compared to healthy individuals (; OR: 1.80; 95% CI: 1.17–2.75). (ii) The presence of this polymorphism was associated more frequently to the presentation of photosensitivity and malar rash (; OR: 3.4; 95% CI: 1.8–6.4).
(i) Analysis of PARP activity in PBMC irradiated with UV-C (280 nm) by measuring NAD concentrations by HPLC
(i) SLE cells UV-irradiated showed a decreased PARP activity compared to irradiated cells from control individuals (). (ii) Activation of PARP decreased according to an increasing SLEDAI score: 77% for patients with 2–9 score, 71% for a 10–14 score, 22% for a 17–23 score, and 15% for a 24–28 score.
(i) DNA extracted from peripheral blood leukocytes
(i) Taiwanese SLE patients (ii) Healthy Taiwanese
(i) Analysis of the distribution of genotypes and allele frequencies for the polymorphisms of the NBS1 gene detected by TaqMan (R) genotyping.
(i) Individuals with Ht1-GGG haplotypes (SLE: 21.75% versus controls: 51.98%, ), Ht2-AAC (SLE: 11.79% versus controls: 30.67%, ), and Ht3-AGC (SLE: 6.63% versus controls: 17.05%, ) of the NBS1 gene present a lower risk of presenting SLE. (ii) Individuals with Ht4-AAG haplotypes (SLE: 23.04% versus controls: 0.29%, ), Ht5-AGG (SLE: 12.58% versus controls: 0.01%, ), and Ht8-GGC SLE: 20.93% versus controls: 0.00%, ) showed an increased risk of presenting this disease.
(i) DNase 1 +/− (ii) DNase 1 −/− mice (iii) Wild type mice (WT)
(i) Generation of a DNase 1 deficiency murine model by exon deletion of the DNase allele (ii) Immunofluorescence evaluation of ANA levels (iii) Histopathological analysis of tissues using H&E or PAS
(i) DNase 1-deficient mice showed classic SLE symptoms, including elevated levels of ANAs (WT: 35% versus DNase 1 −/−: 73%, ) and glomerulonephritis (WT: 0% versus DNase 1 −/− 19% ).
(i) Measurement of DNase 1 activity by the SRED method.
(i) Decreased ADNAsa1 activity in the serum of patients with SLE and with aggregated glomerulonephritis (7 ± 0 ng/ml) compared to controls (16 ± 5.5 ng/ml) and females (14.2 ± 6.5 ng/ml).
(i) RNA extracted from peripheral blood cells (neutrophils and lymphocytes)
(i) SLE patients (ii) Healthy individuals
(i) DNA microarray analysis
(i) 4213 genes were differentially expressed in peripheral blood cells from SLE patients compared to healthy individuals. (ii) 2329 genes were upregulated, which were mainly associated with the immune response. (iii) 1884 genes involved in DNA repair and in ATP synthesis were expressed negatively.
53BP1, SMC1, S phase control point, Fanconi D2 protein, ATM, and nonhomologous DNA-binding proteins.
(i) B lymphoblastoid cell lines obtained from blood samples
(i) SLE pediatric patients (ii) Control patients with ataxia telangiectasia (iii) WT mouse control cells
(i) Determination of repair and recognition activity for double-stranded DNA breaks through 9 trials: (1) NCA, (2) CSA, (3, 4) irradiation-induced foci formation by measuring the γ-H2AX and 53BP1 proteins, (5) kinetics of SMC1 phosphorylation, (6) incorporation of postradiation bromodeoxyuridine to assess the integrity of the S-phase control point, (7) monoubiquitination of the Fanconi D2 protein, (8) expression of the ATM protein, and (9) expression and function of nonhomologous DNA-binding proteins.
(i) 3 of the 9 trials revealed abnormal patterns in response to radiation-induced DNA damage. (ii) 2 of 16 lymphoblastoid cell lines showed an extension in SMC1 phosphorylation.
(i) Serum (ii) Skin biopsies (iii) Kidney and spleen cuts
(i) Pol β mice deficient in Pol β activity (ii) WT control mice
(i) Construction of a POLB mouse model using directed gene disruption, which induced the encoding of an enzyme with slow DNA polymerase activity (ii) Immunofluorescence evaluation of ANA levels (iii) Histopathological analysis of tissues using H&E or PAS
(i) The mouse that expressed the hypomorphic POLB allele developed pathological features very similar to those present in SLE compared to WT mice, including increased levels of immune complexes in glomeruli, elevated levels of serum ANAs, dermatitis, glomerulonephritis, and cervical lymphadenopathy with infiltrate of T and B lymphocytes.
(i) ELISA determination of plasma levels of 8-oxodG (ii) Calculation of the number of mtDNA copies by PCR to detect transcription levels of specific genes (8-oxodG repair enzymes, antioxidant enzymes, proteins related to mitochondrial biogenesis, and glycolytic enzymes).
(i) Increased plasma levels of 8-oxodG in SLE patients () (ii) Lower expression of genes encoding hOGG1 (), antioxidant enzymes (), proteins related to mitochondrial biogenesis (), and glycolytic enzymes () in lupus leukocytes compared to healthy individuals (iii) In SLE patients, the increase in plasma levels of 8-oxodG correlated positively with an increase in leukocyte gene expression of genes encoding hOGG1 (), antioxidant enzymes (), proteins related to mitochondrial biogenesis (), and glycolytic enzymes ().
(i) Genotyping of XRCC5 for the VNTR, and XRCC6-61C> G and XRCC7 6721G> T polymorphisms by PCR and PCR-RFLP, respectively
(i) The presence of the XRCC7 G allele increased the frequency of SLE (). (ii) The frequency of the 1R (), 2R (), and 3R () alleles of the VNTR XRCC5 polymorphism was found to be significantly decreased in SLE patients compared to the control group. (iii) The frequency of the 0R allele () and 2R allele () increased in patients with malar rash. (iv) A decreased presence of the 2R allele was found in patients with a positive ANA test ().
N-ras, γH2AX, Rad51, 84 for DNA damage signaling genes
(i) CMSP
(i) SLE patients (ii) Healthy individuals
(i) Induction of DNA damage and apoptosis with different doses of melphalan (ii) Nucleotide cleavage evaluation by Western blot at different times (monofunctional binding of melphalan to a single DNA site (monoadducts) (iii) Immunofluorescence and confocal laser scanning microscopy evaluation of double-strand DNA rupture repair (iv) PCR detection of the genes involved in the DNA damage response
(i) Defects in DNA repair were found by nucleotide cleavage and DNA repair by double-stranded rupture in SLE patients. (ii) Higher levels of DNA damage were found in patients with lupus nephritis than in those with quiescent SLE () and healthy individuals (). (iii) The rate of apoptosis induced by melphalan was higher in SLE than in control subjects () and inversely correlated with deficiency in DNA repair. (iv) The genes involved in DNA signaling and repair pathways were significantly less expressed in SLE than in control individuals. However, the genes involved in apoptosis were more expressed.
(i) SLE patients (ii) AGS patients (iii) Healthy individuals
(i) Mutation analysis of the 3 subunits of RNase H2 (RNASEH2A, RNA-SEH2B, and RNASEH2C) by PCR in blood samples (ii) Exposure of fibroblasts to UV (250 nm) and analysis of genomic DNA by Southwestern blot (iii) Detection of double-strand DNA breaks and the presence of CPDs in skin biopsies by immunohistochemistry and immunofluorescence
(i) An altered function of RNase H2 correlated with the risk of presenting SLE. (ii) A mild failure conferred a relative risk of 1.6 times (OR, 1.69, ), while a severe condition in RNase H2 increased irrigation to 3.8 times (OR, 3.94, ). (iii) Cutaneous lupus and photosensitivity were the predominant symptoms in SLE patients who had mutations in RNASEH2. (iv) An increase in CPDs in RNase H2-deficient fibroblasts was found in SLE () and AGS () patients compared to control fibroblasts. (v) Injured skin of patients with mutations in RNASEH2B and RNASEH2C had a higher expression of IFN-LES-induced proteins , AGS , and controls
