Histone modifications and methyl-CpG-binding domain protein levels at the TNFSF7 (CD70) promoter in SLE CD4+ T cells

Abstract: In systemic lupus erythematosus (SLE), T lymphocytes overexpress CD70 ( TNFSF7 gene), leading to the synthesis of autoreactive IgGs. CD70 upregulation in SLE CD4+ T cells is associated with hypomethylation of TNFSF7 promoter. In this study, we explored histone modifications in the TNFSF7 promoter region in SLE CD4+ T cells, and characterized the effects of a DNA methyltransferase inhibitor (5-azaC) and a histone deacetylase inhibitor (TSA) on CD70 expression. We found that CD70 mRNA was significantly increased in active lupus CD4+ T cells, and in control cells treated with 5-azaC, TSA, or both. Histone H3 acetylation and dimethylated H3 lysine 4 (H3K4me2) levels were significantly elevated in patients with lupus, and both factors correlated positively with disease activity. MeCP2 protein levels within the TNFSF7 promoter decreased in patients with active lupus. Treatment of CD4+ T cells with 5-azaC alone significantly raised H3K4 dimethyl levels at the TNFSF7 locus. TSA treatment significantly increased H3 and H4 acetylation levels, as well as levels of H3K4 dimethylation at the TNFSF7 locus. Treatment with 5-azaC plus TSA enhanced H3 acetylation levels. These findings indicate that aberrant histone modifications within the TNFSF7 promoter may contribute to the development of lupus by increasing CD70 expression in CD4+ T cells.

Regulation of transcription of hypoxia-inducible factor-1α (HIF-1α) by heat shock factors HSF2 and HSF4

Hypoxia-inducible factor-1α (HIF-1α) is a principal regulator of angiogenesis and other cellular responses to hypoxic stress in both normal and tumor cells. To identify novel mechanisms that regulate expression of HIF-1α, we designed a genome-wide screen for expressed sequence tags (ESTs) that when transcribed in the antisense direction increase production of the HIF-1α target, vascular endothelial growth factor (VEGF), in human breast cancer cells. We discovered that heat shock factor (HSF) proteins 2 and 4-which previously have been implicated in the control of multiple genes that modulate cell growth and differentiation and protect against effects of environmental and cellular stresses-function together to maintain a steady state level of HIF-1α transcription and VEGF production in these cells. We show both HSFs bind to discontinuous heat shock element (HSE) sequences we identified in the HIF-1α promoter region and that downregulation of either HSF activates transcription of HIF-1α. We further demonstrate that HSF2 and HSF4 displace each other from HSF/HSE complexes in the HIF-1α promoter so that HIF-1α transcription is also activated by overexpression of either HSFs. These results argue that HSF2 and HSF4 regulate transcription of HIF-1α and that a critical balance between these HSF is required to maintain HIF-α expression in a repressed state. Our findings reveal a previously unsuspected role for HSFs in control of VEGF and other genes activated by canonical HIF-1α-mediated signaling.

Performance of an automated solid-phase red cell adherence system compared with that of a manual gel microcolumn assay for the identification of antibodies eluted from red blood cells

IgG antibodies coating red blood cells (RBCs) can be removed by elution procedures and their specificity determined by antibody identification studies. Although such testing is traditionally performed using the tube agglutination assay, prior studies have shown that the gel microcolumn (GMC) assay may also be used with comparable results. The purpose of this study was to compare an automated solid-phase red cell adherence (SPRCA) system with a GMC assay for the detection of antibodies eluted from RBCs. Acid eluates from 51 peripheral blood (PB) and 7 cord blood (CB) samples were evaluated by both an automated SPRCA instrument and a manual GMC assay. The concordance rate between the two systems for peripheral RBC samples was 88.2 percent (45 of 51), including cases with alloantibodies (n = 8), warm autoantibodies (n = 12), antibodies with no identifiable specificity (n = 2), and negative results (n = 23). There were six discordant cases, of which four had alloantibodies (including anti-Jka, -E, and -e) demonstrable by the SPRCA system only. In the remaining 2 cases, anti-Fya and antibodies with no identifiable specificity were demonstrable by the GMC assay only. All seven CB specimens produced concordant results, showing anti-A (n = 3), -B (n = 1), maternal anti-Jka (n = 2), or a negative result (n = 1). Automated SPRCA technology has a performance that is comparable with that of a manual GMC assay for identifying antibodies eluted from PB and CB RBCs.

Abnormal DNA methylation in peripheral blood mononuclear cells from patients with vitiligo

BACKGROUND

Vitiligo is a skin disorder characterized by the destruction of melanocytes by autoreactive lymphocytes. The genetic and environmental factors that trigger the autoimmune response are poorly understood. However, alterations to epigenetic DNA methylation patterns contribute to many other autoimmune diseases.

OBJECTIVES

To investigate genomic and gene-specific DNA methylation levels in peripheral blood mononuclear cells (PBMCs) of patients with vitiligo and to relate any changes to the expression of genes that regulate methylation, as well as the autoimmune-related gene IL10.

METHODS

We quantified global methylcytosine levels in PBMCs from 20 patients with vitiligo and 20 healthy controls. mRNA levels of DNA methyltransferases (DNMTs), methyl-DNA binding domain proteins (MBDs) and interleukin (IL)-10 were measured by real-time reverse transcriptase-polymerase chain reaction. Methylation of an IL10 regulatory element domain was determined by bisulphite genomic sequencing.

RESULTS

Genomic DNA methylation in PBMCs of patients with vitiligo was increased relative to healthy controls (P = 0·012). DNMT1, MBD1, MBD3, MBD4 and MeCP2 expression was significantly higher than in control PBMCs (P = 0·013, 0·001, 0·005, 0·001 and 0·001, respectively). MBD1 and MBD3 expression correlated positively with global DNA methylation in vitiligo PBMCs (MBD1: r = 0·519, P = 0·019; MBD3: r = 0·529, P = 0·016). IL10 expression was significantly decreased (P = 0·030), and an IL-10 enhancer region was hypermethylated in vitiligo PBMCs compared with controls (P = 0·014).

CONCLUSIONS

These data show that levels of DNA methylation are altered in PBMCs of patients with vitiligo, and this may contribute to disease activity by affecting the expression of autoimmunity-related genes.

Comparison of radionuclide lymphoscintigraphy and dynamic magnetic resonance lymphangiography for investigating extremity lymphoedema

Background

Lymphoscintigraphy is widely used to image the lymphatic system. The aim of this study was to compare lymphoscintigraphy and dynamic magnetic resonance lymphangiography (MRL) in the investigation of extremity lymphoedema.

Methods

Sixteen patients with primary extremity lymphoedema and two with Klippel–Trenaunay syndrome with lymphoedema were examined by lymphoscintigraphy using the tracer 99Tc-labelled dextran, and by MRL using gadobenate dimeglumine as contrast agent. Morphological abnormalities and functional state of the lymphatic systems of affected limbs were compared between the two imaging methods.

Results

Lymphatic vessels were imaged in 14 of 18 limbs with lymphoedema using MRL, compared with one of 18 using lymphoscintigraphy. MRL detected the inguinal nodes in 16 of 17 patients, whereas lymphoscintigraphy revealed inguinal nodes in only nine. MRL revealed more precise information about structural and functional abnormalities of lymph vessels and nodes than lymphoscintigraphy by real-time measurement of lymph flow in vessels and nodes.

Conclusion

Dynamic MRL was more sensitive and accurate than lymphoscintigraphy in the detection of anatomical and functional abnormalities in the lymphatic system in patients with extremity lymphoedema.

Depression, anxiety and quality of life in parents of children with epilepsy

OBJECTIVES

To assess the impact of childhood epilepsy on parental quality of life (QOL) and psychological health, and to investigate possible correlations between parental QOL and background variables as well as parental anxiety and depression.

SUBJECTS AND METHODS

Parents having an epileptic child (n = 263) and parents having a healthy child (n = 270) were enrolled. Groups were in balance for background variables. Short-Form Health Survey (SF-36) Questionnaire, Zung Depression Scale (ZDS) and Zung Anxiety Scale (ZAS) were applied to all parents. Patients were divided into the first visit group (newly diagnosed epilepsy) and follow-up visit group.

RESULTS

The parents of children with epilepsy had significantly lower QOL scores in SF-36 for all subscales and higher levels of depression and anxiety by using ZDS and ZAS. The factors correlated with parental QOL were seizure control, visit status, anxiety, depression, employment, cost of epilepsy, status epilepticus, drug side effect and age of parents.

CONCLUSIONS

Childhood epilepsy has a severe impact on parental QOL and psychological health, and recognition of possible correlations between parental QOL and background variables will be helpful to improve parental QOL.

Characterization of green fluorescent protein-expressing retinal cone bipolar cells in a 5-hydroxytryptamine receptor 2a transgenic mouse line

Retinal bipolar cells relay visual information from photoreceptors to third-order retinal neurons. Bipolar cells, comprising multiple types, play an essential role in segregating visual information into multiple parallel pathways in the retina. The identification of molecular markers that can label specific retinal bipolar cells could facilitate the investigation of bipolar cell functions in the retina. Transgenic mice with specific cell type(s) labeled with green fluorescent protein (GFP) have become a powerful tool for morphological and functional studies of neurons in the CNS, including the retina. In this study, we report a 5-hydroxytryptamine receptor 2a (5-HTR2a) transgenic mouse line in which expression of GFP was observed in two populations of bipolar cells in the retina. Based on the terminal stratification and immunostaining, all the strongly GFP-labeled bipolar cells were found to be type 4 cone bipolar cells. A small population of weakly labeled bipolar cells was also observed, which may represent type 8 or 9 cone bipolar cells. GFP expression in retinal cone bipolar cells was seen as early as postnatal day 5. In addition, despite severe retinal degeneration due to the presence of the rd1 mutation in this transgenic line, the density of GFP-labeled cone bipolar cells remained stable up to at least 6 months of age. This transgenic mouse line will be a useful tool for the study of type 4 cone bipolar cells in the retina under both normal and disease conditions.

Preoperative transcatheter arterial chemoembolization (TACE) and chemotherapy for hepatic colorectal metastases: Impact on hepatic histology and postoperative outcome

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Background: The objective was to evaluate the effect of preoperative administration of TACE and chemotherapy on hepatic injury and on postoperative outcome in patients with colorectal liver metastases (CRM) Methods: Seventy seven patients underwent hepatic resection for CRM between January 1999 and December 2007 were evaluated. Pathologic review of the non-tumorous liver was performed using established criteria for steatosis, steatohepatitis, and sinusoidal dilation. The effect of two different treatment and hepatotoxicity on postoperative outcome was analyzed. Results: 40 patients (51.9%) received no preoperative treatment, where 27 patients (35.0%) received preoperative chemotherapy, 10 patients (12.9%) performed TACE before resection. The median duration of TACE group was 4.5 months (range, 1–6 months), where the median duration of chemotherapy group was 5 cycles (range, 2–9 cycles). Chemotherapy regimen consisted of oxalipaltin plus FU (29.9%), or irinotecan plus FU (5.2%). On pathologic analysis, 36 patients (46.7%) had steatosis, 24 (31.1%) had sinusoidal dilation, and 8 (10.3%) had steatohepatitis. TACE was associated with steatosis, steatohepatosis and postoperative complication, when compared with no chemotherapy (all p<0.05).Among chemotherapy group,Oxaliplatin was associated with steatohepatitis compared with no preoperative treatment (13.0% v 0%, respectively; p<0.05). Irinotecan was associated with steatohepatitis compared with no preoperative treatment (50% v 0%, respectively; p=0.0006). Patients with preoperative chemotherapy had increased steatohepatitis compared with no treatment group (18.5% v 0%, respectively, p=0.0008), the postoperative morbility rate in preoperative chemotherapy (25.9%) was double that of the no-chemotherapy (12.5%), but this difference was not statistically significant (p=0.20). Preoperative chemotherapy was also not associated with 90-day mortality. Conclusions: Preoperative TACE treatment may cause pathological liver injury, and increase postoperative morbility after hepatic surgery. The standard preoperative chemotherapy regimen with Oxaliplatin or Irinotecan may increase steatohepatis.

No significant financial relationships to disclose.