Young Hee Rho

The Prevalence of Metabolic Syndrome in Patients with Gout: A Multicenter Study

It has been suggested that hyperuricemia and possibly gout are associated with the metabolic syndrome, but there have been no direct studies. This study was undertaken to obtain the prevalence of the metabolic syndrome in patients with gout and to compare it with those from the general population studies. This was a 4-institutional case-historical control study composed of 168 patients with gout. We assessed the prevalence of metabolic syndrome according to the ATP III criteria and compared the prevalence with that of the historical controls. To elucidate the factors in gout that were associated with metabolic syndrome, a multivariate analysis was done. The age-adjusted prevalence of metabolic syndrome in gout patients was 43.6%, which was significantly higher than that of the Korean control population (5.2%) from the previous studies. Patients with gout had more components of metabolic syndrome than did the controls. Body mass index (BMI, OR=1.357 (95%CI 1.111-1.657)) and high density lipoprotein (HDL, OR=0.774 (95%CI 0.705-0.850)) were the variables most significantly associated with the occurrence of metabolic syndrome in gout, but alcohol consumption did not show such associations. Gout is associated with the metabolic syndrome, and furthermore, obesity and dyslipidemia were the factors most associated with the syndrome in these patients.

Prostaglandin E2 augments IL-10 signaling and function.

In inflamed joints of rheumatoid arthritis, PGE2 is highly expressed, and IL-10 and IL-6 are also abundant. PGE2 is a well-known activator of the cAMP signaling pathway, and there is functional cross-talk between cAMP signaling and the Jak-STAT signaling pathway. In this study, we evaluated the modulating effect of PGE2 on STAT signaling and its biological function induced by IL-10 and IL-6, and elucidated its mechanism in THP-1 cells. STAT phosphorylation was determined by Western blot, and gene expression was analyzed using real-time PCR. Pretreatment with PGE2 significantly augmented IL-10-induced STAT3 and STAT1 phosphorylation, as well as suppressors of cytokine signaling 3 (SOCS3) and IL-1R antagonist gene expression. In contrast, PGE2 suppressed IL-6-induced phosphorylation of STAT3 and STAT1. These PGE2-induced modulating effects were largely reversed by actinomycin D. Pretreatment with dibutyryl cAMP augmented IL-10-induced, but did not change IL-6-induced STAT3 phosphorylation. Misoprostol, an EP2/3/4 agonist, and butaprost, an EP2 agonist, augmented IL-10-induced STAT3 phosphorylation and SOCS3 gene expression, but sulprostone, an EP1/3 agonist, had no effect. H89, a protein kinase A inhibitor, and LY294002, a PI3K inhibitor, diminished PGE2-mediated augmentation of IL-10-induced STAT3 phosphorylation. In this study, we found that PGE2 selectively regulates cytokine signaling via increased intracellular cAMP levels and de novo gene expression, and these modulating effects may be mediated through EP2 or EP4 receptors. PGE2 may modulate immune responses by alteration of cytokine signaling in THP-1 cells.

Meta-analysis of genome-wide linkage studies for bone mineral density

AbstractGenome-wide linkage studies have shown several chromosome loci that may harbor genes that regulate bone mineral density (BMD), but results have been inconsistent. A meta-analysis was performed to assess evidence for linkage of BMD across whole genome scan studies. Eleven whole-genome scans of BMD or osteoporosis containing 3,097 families with 12,685 individuals were included in this genome scan meta-analysis (GSMA). For each study, 120 genomic bins of ∼30 cM were defined and ranked according to maximum evidence for linkage within each bin. Bin ranks were weighted and summed across all studies. The summed rank for each bin was assessed empirically for significance using permutation methods. A total of seven bins lie above the 95% confidence level (P=0.05) and one bin was above the 99% confidence level (P=0.01) in the GSMA of eleven linkage studies: bins 16.1 (16pter-16p12.3, Psumrnk <0.01), 3.3 (3p22.2-3p14.1), 1.1 (1pter-1p36.22), 18.2 (18p11.23-18q12.2), 6.3 (6p21.1-6q15), 20.1 (20pter-20p12.3), and 18.1 (18pter-18p11.23). GSMA was performed with seven studies with linkage scores of LOD >1-1.85 for sensitivity test, confirming the linkage on chromosome 16p and 3p and revealing evidence of new linkage in bins 10.2 (10p14-10q11.21) and 22.2 (22q12.3-22pter). In conclusion, the meta-analysis of whole-genome linkage studies of BMD has shown chromosome 16pter-16p12.3 to have the greatest evidence of linkage as well as revealing evidence of linkage in chromosomes 1p, 3p, 6, 10, 18, 20p, and 22q across studies. This data may provide a basis with which to carry out targeted linkage and candidate gene studies particularly in these regions.

Scleroderma associated with ANCA-associated vasculitis

Scleroderma and ANCA-associated vasculitides (AAV), such as microscopic polyangiitis, are distinct disease entities, but are rarely known to coexist with each other. We have reported on two cases of scleroderma patients for the first time in Korea, and these patients were initially known to have only limited type scleroderma with pulmonary fibrosis, but eventually they were found to be ANCA-positive with the associated clinical features of vasculitis. Both were treated with high-dose steroids and cyclophosphamide and remitted without major sequelae. When scleroderma patients exhibit atypical features such as normotensive renal failure with signs of active inflammation, the possibility of AAV should always be considered.

Ankylosing spondylitis susceptibility loci defined by genome-search meta-analysis

AbstractIn genome scans of ankylosing spondylitis (AS), with the exception of the HLA loci, linkage has not been easy to replicate across studies. We applied the genome-search meta-analysis (GSMA) method to genome scans of AS and spondyloarthropathy (SpA) to assess evidence for linkage across studies. Three AS genome scans and one SpA scan including 430 families with 1,048 affected individuals were used. All four original genome scans mainly analyzed Caucasian families. Seven bins had both Psumrnk and Pord <0.05, suggesting these bins most likely contain AS-linked loci; bin 6.2, 6.1, 6.3, 16.3, 19.2, 17.1, and 16.4. The GSMA produced significant genome-wide evidence for linkage on chromosome 6p22.3-6p21.1 (Psumrnk=0.000003), including the HLA locus. In addition to the HLA-B27 locus, strong linkage evidence was found on chromosome 6p25.3-6p22.3 (Psumrnk=0.0013) and 6p21.1-6p15 (Psumrnk=0.043). In the GSMA of four genome scans including one SpA study, the bin 9.4 (9q21.32-9q33.1) was newly found for linkage (Psumrnk=0.043, Pord=0.013). This GSMA added the evidence of the HLA loci as the greatest susceptibility factor to AS and showed evidences of chromosome 6, 16q, 19, 17p, and 9q as non-HLA susceptibility loci.

Osteoarthritis susceptibility loci defined by genome scan meta-analysis

Genome scans for osteoarthritis (OA) have yielded inconsistent results. The absence of replication of linkage might be due to the lack of power of individual studies. A meta-analysis of published data was performed to assess evidence for linkage of OA across genome scan studies. Three OA whole-genome scans including 893 families with 3,000 affected individuals were used for genome scan meta-analysis (GSMA). A total of five bins lie above 95% confidence level (P=0.05) and one bin is above 99% confidence level (P=0.01) in OA GSMA; bins 7.6 (7q34–7q36.3, Psumrnk =0.0035), 11.3 (11p12–11q13.4), 6.3 (6p21.1–6q15), 2.8 (2q31.1–2q34) and 15.3 (15q21.3–15q26.1). The highest summed bin was bins 7.6. In conclusion, the OA GSMA has shown that chromosome 7q34–7q36.3 have the highest summed rank and four additional loci with significant summed ranks across studies.

Interleukin-1 receptor antagonist gene polymorphism and rheumatoid arthritis

The aim of this study was to evaluate the association of polymorphism in IL-1 receptor antagonist (IL-1RA) gene intron 2 with susceptibility to rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) and their clinical features. Polymerase chain reaction of a genomic DNA was used to determine genotypes of the IL-1RA in 138 RA, 93 SLE, and 127 healthy control subjects. The frequency of IL-1RA allele 2 (IL-1RN*2) was lower in RA patients (2.5%) than in control subjects (7.1%) (odds ratio 0.34, 95% confidence interval 0.13–0.88, P=0.02). There was a significant difference in genotype and allele distribution between RA patients and controls. However, it did not differ between SLE patients and controls. In SLE and RA patients, there was no significant difference in clinical and laboratory findings concerning IL-1RA polymorphisms. In conclusion, our data suggest that IL-1RA gene polymorphism is not responsible for specific clinical characteristics in RA and SLE but that IL-1RN*2 is relevant in the susceptibility to RA, suggesting a protective role of IL-1RN*2 in the pathogenesis of RA.

Intron 4 polymorphism of the endothelial nitric oxide synthase gene is associated with the development of lupus nephritis

The objective was to investigate whether the functional polymorphism of intron 4 in the endothelial nitric oxide synthase (eNOS) gene is associated with susceptibility to systemic lupus erythematosus (SLE) and its clinical features. The 27-bp repeat polymorphism in intron 4 of the eNOS gene was determined by polymerase chain reaction in 88 SLE patients and 95 healthy control subjects. Clinical manifestations were analysed in each patient and correlated with the genotypes. The genotype distribution of the intron 4 of the eNOS did not differ between SLE patients and control subjects (aa, ab, bb genotypes 0, 15, 73 versus 2, 19, 74 controls respectively, chi-squared 2.21, 2 df, P 0.331). In the lupus patients according to the intron 4 genotypes of the eNOS, there was no clinically significant difference in age at onset, anti-dsDNA titre, C3, C4 level, SLEDAI, SLICC/ACR Damage Index, or autoantibodies such as RF, anti-Ro, La, RNP, Sm, or phospholipid antibodies. However, renal involvement was higher in patients with ab genotypes than in those with bb genotypes (53% versus 26%), but it did not reach statistical significance (P 0.062). Logistic regression showed that having the ab genotype was a significant risk factor for the development of lupus nephritis (odds ratio 3.28, 95%CI: 1.04-10.2, P 0.04). In conclusion, our data show that the eNOS ab genotypes may be associated with the development of lupus nephritis, suggesting individuals who carry the ‘a’ allele are more susceptible to lupus nephritis than those with the ‘b’ allele.

15-Deoxy-Δ12,14-PGJ2 inhibits IL-6-induced Stat3 phosphorylation in lymphocytes

15-Deoxy-Δ12,14-PGJ2 (15d-PGJ2 ) is a natural ligand that activates the peroxisome proliferators-activated receptor (PPAR) γ, a member of nuclear receptor family implicated in regulation of lipid metabolism and adipocyte differentiation. Recent studies have shown that 15d-PGJ2 is the potent anti-inflammatory agent functioning via PPARγ-dependent and -independent mechanisms. Most postulated mechanisms for anti-inflammatory action of PPARγ agonists are involved in inhibiting NF-κB signaling pathway. We examined the possibility that IL-6 signaling via the Jak-Stat pathway is modulated by 15d-PGJ2 in lymphocytes and also examined whether the inhibition of IL-6 signaling is dependent of PPARγ. 15d-PGJ2 blocked IL-6 induced Stat1 and Stat3 activation in primary human lymphocytes, Jurkat cells and immortalized rheumatoid arthritis B cells. Inhibition of IL-6 signaling was induced rapidly within 15 min after treatment of 15d-PGJ2 . Other PPARγ-agonists, such as troglitazone and ciglitazone, did not inhibit IL-6 signaling, indicating that 15d-PGJ2 affect the IL-6-induced Jak-Stat signaling pathway via PPARγ-independent mechanism. Although cycloheximide reversed 15d-PGJ2 -mediated inhibition of Stat3 activation, actinomycin D had no effect on 15d-PGJ2 -mediated inhibition of IL-6 signaling, indicating that inhibition of IL-6 signaling occur independent of de novo gene expression. These results show that 15d-PGJ2 specifically inhibit Jak-Stat signaling pathway in lymphocytes, and suggest that 15d-PGJ2 may regulate inflammatory reactions through the modulation of different signaling pathway other than NF-κB in lymphocytes.

The functional p53 codon 72 polymorphism is associated with systemic lupus erythematosus

The aim of the study is to investigate whether the functional p53 codon 72 polymorphism is associated with susceptibility to SLE and its clinical features. A polymerase chain reaction of genomic DNA-restriction fragment length polymorphism was used to determine genotypes of the p53 codon 72 in 90 SLE patients and 114 healthy controls. Clinical/serological manifestations were analysed in each patient and correlated with the genotypes. The OR of the association of the Pro allele with SLE was 1.70 (95% CI, 1.15-2.53, P = 0.0079) and the OR of the Pro/Pro (a recessive model) was significantly increased (OR = 2.58, 95% CI = 1.24-5.39, P = 0.0093). The Armitage’s trend test indicated a significant dosage effect of the Pro allele for SLE (OR = 1.73, chi-square = 7.08, P = 0.0078). However, there was no significant association of the polymorphism with clinical/serological manifestations studied here. In conclusion, our finding suggests the functional p53 codon 72 polymorphism may be associated with SLE susceptibility, suggesting individuals who carry the Pro allele may have a higher risk to SLE susceptibility than those with the Arg allele. Further studies for replications are needed to confirm that the p53 polymorphism contributes to SLE.