Overexpression of methyl-CpG-binding protein 2 and autoimmunity: evidence from MECP2 duplication syndrome, lupus, MECP2 transgenic and Mecp2 deficient mice

Methyl-CpG-binding protein 2 (MeCP2) is a key transcriptional regulator that can induce either silencing or activation of target genes. Genetic polymorphisms in the MECP2 /IRAK1 locus have been associated with increased susceptibility to multiple autoimmune diseases such as lupus, primary Sjogren's syndrome, and more recently rheumatoid arthritis. Data from our group suggest that the disease risk variant in this locus is associated with gain of MeCP2 function. Recent findings indicate that MECP2 duplication in human results in defective T helper cell type 1 (TH1) response and IFN-γ production. Herein, we discuss the data from children with MECP2 duplication, human lupus, and from the human MECP2 transgenic and Mecp2 deficient mice to support a link between MECP2 overexpression and autoimmunity. We also provide findings from an Mecp2 deficient mouse that independently support a role for MeCP2 in the immune response and specifically in IFN-γ expression.

Importance of epigenetic mechanisms in visceral pain induced by chronic water avoidance stress

Epigenetic molecular mechanisms, which include DNA methylation and histone deacetylation, are implicated in the dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis. Previously, we demonstrated that repeated water avoidance stress (WAS), a validated model of chronic psychological stress, induces heightened visceral pain behaviors in rodents that resemble irritable bowel syndrome (IBS) sequelae. However, the involvement of epigenetic molecular mechanisms in the pathophysiology of stress-induced visceral pain has not been explored. Our hypothesis is that epigenetic mechanisms within the central nervous system (CNS) are important to chronic stress-induced visceral hypersensitivity. Adult male F-344 rats with intracerebroventricular (i.c.v.) cannulae were exposed to 7 days of repeated WAS. Controls received a SHAM stress. Following the daily 1h stressor, trichostatin A (TSA; 100 ng/ml), a potent histone deacetylase inhibitor, or vehicle (VEH; 0.1% DMSO/saline,) as control was administered via the i.c.v. cannula. Visceral sensitivity was assessed 24h after the final WAS and quantified the visceromotor response (VMR) by recording the number of abdominal contractions in response to graded pressures (20-60 mmHg) of colorectal distensions (CRD). From a separate group of rats that were exposed to repeated WAS or SHAM stress, the amygdala was isolated to assess the methylation status of glucocorticoid receptor (GR) and corticotropin releasing-factor (CRF) genes via bisulfite sequencing and verified by pyrosequencing. GR and CRF gene expression was quantified via qRT-PCR. Stressed rats exhibited visceral hypersensitivity that was significantly attenuated by TSA. Compared to SHAM controls, methylation of the GR gene was increased following WAS while expression of the GR gene was decreased. Methylation of the CRF promoter was decreased with WAS with a concomitant increase in CRF expression. This study demonstrates the involvement of central epigenetic mechanisms in regulating stress-induced visceral hypersensitivity and provides a foundation for exploring the epigenetic mechanisms that may contribute to IBS-like symptomatology.

Haemolytic anaemia in a multi-ethnic cohort of lupus patients: a clinical and serological perspective

Systemic lupus erythematosus is a chronic autoimmune disease that can be associated with a variety of haematological manifestations. We identified 76 patients with haemolytic anaemia in a cohort of 1251 unrelated female lupus patients enrolled in our studies. The presence of the various American College of Rheumatology clinical criteria for lupus and serological specificities were determined in lupus patients with haemolytic anaemia and compared with a group of race-matched control lupus patients without haemolytic anaemia. Clinical data were obtained from medical records, and serological specificities were determined in our clinical immunology laboratory at OMRF. The presence of haemolytic anaemia in lupus patients was associated with a higher frequency of proteinuria (OR = 2.70, P = 0.000031), urinary cellular casts (OR = 2.83, P = 0.000062), seizures (OR = 2.96, P = 0.00024), pericarditis (OR = 2.21, P = 0.0019), pleuritis (OR = 1.72, P = 0.028) and lymphopenia (OR = 1.79, P = 0.015). These findings were independent of the presence of thrombocytopenia, which was approximately five times more common in lupus patients with haemolytic anaemia. Lupus patients with haemolytic anaemia were about 8 years younger than lupus patients without haemolytic anaemia at the time of disease onset (P = 0.000001). In the absence of thrombocytopenia, lupus patients with haemolytic anaemia were approximately two times more likely to have anti-dsDNA antibodies (P = 0.024). The presence of haemolytic anaemia is associated with a subset of lupus characterized by a younger age of disease onset, and a more severe disease with a higher likelihood of renal involvement, seizures, serositis and other cytopenias.

Sulpha allergy in lupus patients: a clinical perspective

Abstract

Systemic lupus erythematosus is a chronic, relapsing autoimmune disease that can affect multiple organ systems. An increased prevalence of drug allergy has been reported in lupus patients compared with the general population. Using a cohort of 417 lupus patients, we found a history of sulpha allergy in 27.3% of patients. European-American lupus patients with sulpha allergy are about two times more likely to suffer from lymphopenia, two times more likely to have anti-Ro autoantibody, and four times less likely to have anti-nRNP antibodies compared with lupus patients without a reported sulpha allergy ( P = 0.0075, 0.025, and 0.032, respectively). In African-American lupus patients, a history of sulpha allergy was associated with over three times increased odds of developing pericarditis ( P = 0.005).

Genetic association of interleukin-21 polymorphisms with systemic lupus erythematosus

OBJECTIVE

The aetiology of systemic lupus erythematosus (SLE) is incompletely understood. Both genetic and environmental factors are implicated in the pathogenesis of the disease. Herein, we describe genetic association between SLE and polymorphisms in the interleukin (IL)-21 gene. The reported effect of IL-21 on B-cell differentiation into plasma cells and its effect on dendritic cell maturation and T-cell responses make IL-21 an attractive candidate gene for SLE.

METHODS

Three single nucleotide polymorphisms (SNPs) in the IL-21 gene were genotyped in a total of 2636 individuals (1318 cases and 1318 controls matched for age, sex and race). Population-based case-control association analyses were performed.

RESULTS

We found a genetic association with SLE and two SNPs located within the IL-21 gene (rs907715: chi(2) = 11.55, p<0.001; rs2221903: chi(2) = 5.49, p = 0.019). Furthermore, genotypes homozygous for the risk alleles were more frequent than genotypes homozygous for the non-risk alleles in European-American patients as compared to controls (rs907715 (GG versus AA): odds ratio (OR) = 1.66, p = 0.0049; rs2221903 (GG versus AA): OR = 1.60, p = 0.025).

CONCLUSION

Our findings indicate that IL-21 polymorphism is a candidate association with SLE. The functional effects of this association, when revealed, might improve our understanding of the disease and provide new therapeutic targets.

Genetic linkage of systemic lupus erythematosus with chromosome 11q14 (SLEH1) in African-American families stratified by a nucleolar antinuclear antibody pattern

Systemic lupus erythematosus (SLE) is an autoimmune disease with complex genetics. We evaluated pedigrees multiplex for SLE that had an affected with antinucleolar antibodies to increase the homogeneity for genetic linkage analysis. We found a significant linkage effect on chromosome 11q14 at marker D11S2002 in African-American Pedigrees. This effect produced a maximum LOD score of 5.62 using a dominant inheritance model with 95% penetrance in males and 99% penetrance in females. The results were supported by multipoint linkage analysis. Fine mapping of the region with two additional markers within 6 cM of D11S2002 further provided evidence of linkage in this region. Linkage at D11S2002, named SLEH1, was previously found in some of these same African-American pedigrees multiplex for SLE, but who were stratified by hemolytic anemia (Kelly et al, submitted). In conclusion, an important SLE susceptibility gene, SLEH1 at 11q14, is identified in African-Americans when stratifying pedigrees by antinucleolar autoantibodies.

Ankylosing spondylitis in north Jordan: descriptive and analytical study

OBJECTIVE

A study of ankylosing spondylitis in Jordan, which has been under investigated in this region.

METHODS

Twenty two patients were studied according to standard methodology during a period of four years. Information on HLA, the presence of uveitis, cardiac disease, and peripheral arthritis was recorded. Other variables such as age, sex, employment, and level of disability were also recorded.

RESULTS

The results reflected the characteristics of the illness and the impact of the disease on the patients and their quality of life and were consistent with the findings of other workers in the region.