Archive of Medical Research

Complement factor H polymorphisms, renal phenotypes and age-related macular degeneration: the Blue Mountains Eye Study.

Complement factor H (CFH) is a key regulator of the alternative pathway of complement and its mutations have been associated with membranoproliferative glomerulonephritis type II, atypical hemolytic uremic syndrome and age-related macular degeneration (AMD), suggesting that alternative pathway dysregulation is a common pathogenetic feature of these ocular and renal conditions. In this study we tested the hypothesis that common CFH variants have a global role in renal function in the Australian population-based Blue Mountains Eye Study (BMES). We replicated the association of I62V with estimated glomerular filtration rate (GFR; P=0.017) and creatinine clearance (CRCL; P=0.015). The minor allele of I62V (G) was deleterious: adding one copy of the G allele decreased GFR/CRCL by approximately 0.98 ml min(-1) per 1.73 m(2) (95% confidence interval (CI): 0.97, 0.99). We also replicated the association of Y402H with AMD and provided an unbiased estimate of population attributable risk (PAR). The minor allele of Y402H (C) was deleterious: the odds ratio estimate of CC genotype compared to TT was 1.87 (95% CI: 1.44, 2.45). The PAR of the C allele was estimated as 0.22 (95% CI: 0.15, 0.28). In summary, in the BMES population we confirmed the association between I62V and renal function, as measured by the estimated GFR, plus the association of Y402H with both early- and late-stage AMD.Genes and Immunity advance online publication, 13 March 2008; doi:10.1038/gene.2008.10.

Xing C, Sivakumaran TA, Wang JJ, Rochtchina E, Joshi T, Smith W, Mitchell P, Iyengar SK.

[1] 1Department of Epidemiology and Biostatistics, Case Western Reserve University, Cleveland, OH, USA [2] 2Department of Clinical Sciences, University of Texas Southwestern Medical Center, Dallas, TX, USA [3] 3McDermott Center of Human Growth and Development, University of Texas Southwestern Medical Center, Dallas, TX, USA.

From model cell line to in vivo gene expression: disease-related intestinal gene expression in IBD.

Crohn\’s disease (CD) and ulcerative colitis (UC) are subforms of inflammatory bowel diseases (IBD). Genetic and environmental factors influencing the onset and course of the diseases have been recently identified. This study uses a two-step approach to detect genes involved in the pathogenesis of IBD by microarray analysis and real-time PCR (RT-PCR). In a first step, microarray expression screening was used to obtain tumour necrosis factor-alpha (TNF-alpha) induction profiles of two human cell lines to represent the tissue cell types involved in IBD. In a second step, a subset of differentially expressed genes was examined by real-time PCR in intestinal biopsy samples of normal controls (NC) compared with UC and CD patients, as well as to a cohort of patients suffering from intestinal diseases other than IBD. Data were obtained from 88 CD, 88 UC, 53 non-IBD patients (inflammatory control), DC and 45 NC individuals. The experimental design enabled the identification of disease-specific expressed genes. DnaJ (Hsp40) homologue, subfamily B, member 5 (DNAJB5) was downregulated in intestinal biopsy samples of the UC cohort compared with NC. A difference in JUNB expression levels was observed by comparing biopsy samples from inflamed and non-inflamed areas of UC patients. Transcript expression differences between IBD and control cohorts were found by examining histamine N-methyltransferase (HNMT), interleukin-1A (IL-1A) and proplatelet basic protein (PPBP) expression. The experimental procedure represents an approach to identify disease-relevant genes, which is applicable to any disease where appropriate model systems are available.Genes and Immunity advance online publication, 13 March 2008; doi:10.1038/gene.2008.11.

Schulze HA, Häsler R, Mah N, Lu T, Nikolaus S, Costello CM, Schreiber S.

1Institute for Clinical Molecular Biology, University Hospital Schleswig-Holstein, Kiel, Germany.

The association between type 1 diabetes and the ITPR3 gene polymorphism due to linkage disequilibrium with HLA class II.

A fine mapping study of the MHC region in a Swedish case-control population sample reported a novel type 1 diabetes (T1D) association from the inositol 1-, 4-, 5-trisphosphate receptor type 3 gene (ITPR3) in a case-control study, reportedly independent of the HLA class II effect. We attempted to replicate this novel association in a family-based study of 1120 T1D families with at least one affected child, an approach immune to population stratification. We found association of the ITPR3 single nucleotide polymorphisms (SNPs) rs2296336 with T1D but in a direction opposite to that reported. Moreover, rs2296336 was in linkage disequilibrium (LD) with specific alleles of the HLA DQB1 gene. Conditional regression showed that all of the ITPR3 SNP T1D association could be accounted for by the DQB1 effect. Therefore, our findings do not support an obvious role of genetic variation of the ITPR3 gene in T1D risk.Genes and Immunity advance online publication, 13 March 2008; doi:10.1038/gene.2008.12.

Qu HQ, Marchand L, Szymborski A, Grabs R, Polychronakos C.

1Endocrine Genetics Lab, The McGill University Health Center (Montreal Children\’s Hospital), Montréal, Québec, Canada.

Combination of KIR and HLA gene variants augments the risk of developing birdshot chorioretinopathy in HLA-A*29-positive individuals.

Birdshot chorioretinopathy (BCR), a chronic ocular inflammatory disease with characteristic choroidal lymphocytic infiltrates, has been strongly associated with human leukocyte antigen (HLA)-A29. Although HLA-A29 occurs frequently in all populations, BCR affects only a small percentage of HLA-A29-positive Caucasians, indicating additional susceptibility factors for BCR. Discovery of HLA class I-specific killer cell immunoglobulin-like receptors (KIR) led to a series of epidemiological studies implicating KIR-HLA gene combinations in disease. Here, we characterized KIR-HLA pairs in BCR patients and controls carrying HLA-A*29 as well as controls lacking HLA-A*29. KIR-HLA pairs implicated for weak inhibition (KIR2DL2/3+HLA-C1 and KIR3DL1+HLA-Bw4(T80)) in combination with activating KIR genes associated with autoimmunity (KIR2DS2, 2DS3 and 2DS4) augment the risk of developing BCR in HLA-A*29-positive individuals. The reciprocal association of strong inhibitory pairs (KIR3DL1+HLA-Bw4(I80) and KIR2DL1+HLA-C2) in combination with those implicated in protection from infection (KIR3DS1+HLA-Bw4(I80) and KIR2DS1+HLA-C2) was observed in HLA-A*29-negative controls. These results suggest that a profound effect of KIR2DS2/S3/S4 in the absence of strong inhibition may enhance the activation of natural killer cells and T-cell subsets against intraocular self-antigens, thereby contributing to pathogenesis of BCR.Genes and Immunity advance online publication, 13 March 2008; doi:10.1038/gene.2008.13.

Levinson RD, Du Z, Luo L, Monnet D, Tabary T, Brezin AP, Zhao L, Gjertson DW, Holland GN, Reed EF, Cohen JH, Rajalingam R.

1Ocular Inflammatory Disease Center, Jules Stein Eye Institute, David Geffen School of Medicine at UCLA, University of California at Los Angeles, Los Angeles, CA, USA.

Lack of association between genetic variation in G-protein-coupled receptor for asthma susceptibility and childhood asthma and atopy.

G-protein-coupled receptor for asthma susceptibility (GPRA or GPR154) was identified as an asthma and atopy candidate gene by positional cloning. Some subsequent studies suggest associations of GPRA single nucleotide polymorphisms (SNPs) and haplotypes with asthma or atopy susceptibility. However, the associated SNPs or haplotypes vary among studies. The role of GPRA genetic variation in asthma and atopy remains unsolved. Published data on GRPA variants and asthma come exclusively from Caucasian and Asian populations. We examined whether GPRA SNPs and haplotypes are associated with asthma and atopy in a Mexican population. We genotyped and analyzed 27 GPRA SNPs in 589 nuclear families consisting of asthmatic children aged 4-17 years of age and their parents in Mexico City. Atopy was determined by skin prick tests to 25 aeroallergens. The 27 SNPs examined provided excellent coverage of the GPRA gene. GPRA SNPs and haplotypes were not associated with childhood asthma and the degree of atopy to aeroallergens in a Mexican population. Our review of studies of GPRA variants in relation to asthma phenotypes shows considerable heterogeneity. Accordingly, our results suggest that GPRA variants are not an important contributor to childhood asthma and atopy susceptibility in a Mexican population.Genes and Immunity advance online publication, 13 March 2008; doi:10.1038/gene.2008.8.

Wu H, Romieu I, Sienra-Monge JJ, Del Rio-Navarro BE, Burdett L, Yuenger J, Li H, Chanock SJ, London SJ.

1Laboratory of Respiratory Biology, Division of Intramural Research, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, NC, USA.

The effect of NOD2 activation on TLR2-mediated cytokine responses is dependent on activation dose and NOD2 genotype.

The mechanism by which mutations in NOD2 predispose to Crohn\’s disease (CD) is incompletely understood. In mice, NOD2 has been found to function as a negative regulator of Toll-like receptor 2 (TLR2) signaling. In contrast, studies in humans so far showed no negative regulatory interaction between NOD2 and TLR2, and in fact suggest a synergistic effect between the two. Here, we show that this interaction is dose dependent. Adding low doses of muramyl dipeptide (MDP) to TLR2 primed monocytes results in a significant increase in cytokine production, whereas adding higher doses of MDP led to a striking downregulation of the responses. This downregulation by high-dose MDP does not occur in monocytes from NOD2-deficient patients. The inhibitory role of NOD2 at high concentrations of MDP implicates a safety mechanism to prevent exaggerated antibacterial immune responses in the gut to high or perpetuating bacterial load. This regulatory mechanism is lost in NOD2-deficient CD patients.Genes and Immunity advance online publication, 13 March 2008; doi:10.1038/gene.2008.9.

Borm ME, van Bodegraven AA, Mulder CJ, Kraal G, Bouma G.

1Department of Molecular Cell Biology and Immunology, Vrije Universiteit Medical Center, Amsterdam, The Netherlands.

In vivo restoration of RhoB expression leads to ovarian tumor regression.

Ovarian cancers are very aggressive cancers most often diagnosed when metastasis has already occurred in the entire peritoneal cavity. Ovarian adenocarcinoma cells present an undetectable level of RhoB GTPase. Using preclinical ovarian cancer models, we aimed to evaluate the potential use of RhoB cDNA as a tumor suppressor gene in gene therapy. RhoB restoration in vitro, through recombinant adenovirus transduction, resulted in the apoptosis of endogenous RhoB protein low-expressing cell lines (OVCAR-3 and IGROV-1) through the activation of the intrinsic apoptotic caspase cascade. We showed that a single injection of 10(8) p.f.u. of adenoviral vector encoding a reporter gene into the peritoneal cavity of ovarian tumor bearing mice can induce the gene modification of a large quantity of cells throughout the cavity. We thereby tested the effect of AdRhoB injections to treat ovarian cancer-bearing mice. The ectopic expression of RhoB, following its introduction via viral transduction into nude mice in vivo, was highly effective in suppressing tumor growth of ovarian cancer xenografts. Therapeutic agents designed to correct defects of RhoB at the molecular level may thereby provide innovative treatment options for patients not responding to standard therapies.Cancer Gene Therapy advance online publication, 14 March 2008; doi:10.1038/cgt.2008.12.

Couderc B, Pradines A, Rafii A, Golzio M, Deviers A, Allal C, Berg D, Penary M, Teissie J, Favre G.

[1] 1INSERM U563, CPTP, Toulouse, France; Institut Claudius Regaud, Toulouse, France [2] 2Faculté des Sciences Pharmaceutiques, University Toulouse III, Toulouse, France [3] 3EA3035, Institut Claudius Regaud, Toulouse, France.

Silencing Livin gene expression to inhibit proliferation and enhance chemosensitivity in tumor cells.

Livin, a novel member of the human inhibitors of apoptosis protein (IAP) family, plays an important role in tumor progression and occurrence by inhibiting cell apoptosis. It is selectively expressed in the most common human neoplasms and appears to be involved in tumor cell resistance to chemotherapeutic agents. To investigate its possibility as a therapeutic target for human malignancies, we established two genetically different stable tumor cell lines (LoVo and SPCA-1) and RNA interference (RNAi) technique was employed to downregulate Livin expression in two human tumor cell lines. The specific downregulation of Livin expression in tumor cell lines significantly inhibited in vitro cell proliferation and in vivo tumorigenicity. Furthermore, Livin knockdown led to cell arrest in the G(1)/G(0) phase of cell cycle, eventual apoptosis and chemosensitivity enhancement in tumor cells. All these results indicate that RNAi-mediated downregulation of Livin expression can lead to potent antitumor activity and chemosensitizing effects in human cancers.Cancer Gene Therapy advance online publication, 14 March 2008; doi:10.1038/cgt.2008.16.

Wang R, Lin F, Wang X, Gao P, Dong K, Zou AM, Cheng SY, Wei SH, Zhang HZ.

1Department of Clinical Diagnosis, Tangdu Hospital, Fourth Military Medical University, Xi\’an, Shaanxi, China.

A permanent tan from iron.

Lim R, Irvine T, Ahmed MS, Abraham K, Wong CF.

Department of Nephrology, Aintree University Hospitals NHS Foundation Trust, Liverpool, UK.

The case / Acute renal failure and anemia.

Chen H, Liu Z, Li L.

Research Institute of Nephrology, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China.