Association of interleukin 1 gene family polymorphisms with duodenal ulcer disease

Cytokine genes taking part in the immunological response to Helicobacter pylori infection are good candidates to study for genetic predisposition to duodenal ulcer disease (DU). Among cytokines, interleukin (IL)-1beta and its natural specific inhibitor, the interleukin-1 receptor antagonist, are cytokines that play a key role in regulating gastric acid secretion and modulating the immune response in the gastrointestinal mucosa. We aimed to investigate whether polymorphisms in the IL-1B and IL-1RN genes are involved in the susceptibility to duodenal ulcer. DNA from 131 unrelated Spanish Caucasian patients with DU and 105 ethnically matched healthy controls was typed for the IL-1B-511, IL-1B-31, and IL-1B + 3954 gene polymorphisms, and the VNTR polymorphism in intron 2 of the IL-1RN gene by polymerase chain reaction (PCR)-based methods and TaqMan assays. H. pylori status and non-steroidal anti-inflammatory drugs (NSAIDs) use was determined in all patients and controls. Logistic regression analysis identified H. pylori infection (OR: 9.74; 95%CI = 3.53-26.89) and NSAIDs use (OR: 8.82; 95%CI = 3.51-22.17) as independent risk factors for DU. In addition, the simultaneous carriage of IL-1RN*2, IL-1B-511*C, IL-1B-31*T and IL-1B + 3954*C alleles was a genetic risk factor for DU in patients with H. pylori infection (OR: 3.22; 95%CI = 1.09-9.47). No significant differences in IL-1RN and IL-1B genotypes were found when patients were categorized according to gender, age of onset, smoking habit, NSAIDs use, type of complication and positive family history. Our results provide further evidence that host genetic factors play a key role in the pathogenesis of duodenal ulcer.     

Association between polymorphisms in the human chemokine receptor genes CCR2 and CX3CR1 and rheumatoid arthritis

Cell trafficking into the rheumatoid synovium is thought to play an important role in the inflammation seen in rheumatoid arthritis. Chemokine receptors play a central role in this process, and several common variants are known, including the CCR2 variant, CCR2-64I, and two variants of the CX3CR1 gene, V249I and T280M. All three variants result in functional amino acid substitutions. We studied the association of these chemokine receptor variants with susceptibility to and severity of rheumatoid arthritis in two Dutch patient populations; 282 consecutive rheumatoid arthritis patients from a rheumatology outpatient clinic, and a cohort of 101 female rheumatoid arthritis patients, followed closely for a 12-year period, from whom hand and feet X-rays taken at three year intervals were scored and analyzed in this study. Although there was a trend towards increased severity of disease in patients carrying CX3CR1 variants, this was not independent of known risk factors. We found no evidence for a significant independent role for the CCR2 and CX3CR1 variants in the susceptibility to or severity of rheumatoid arthritis.     

Human papillomavirus type 16 E5 protein (review)

The association of certain human papillomavirus (HPV) types with malignancies of the anogenital tract is well established. The virus type most frequently associated with cellular transformation is HPV 16, as has been shown in epidemiological studies. Its transforming capacity has also been demonstrated in many in vitro cell transformation experiments. The most potent oncogenes of HPV 16 are the E6 and E7 proteins, but the E5 protein, whose homologue is the main oncogene of bovine papillomavirus, has recently been identified as an oncogene also for HPV. On the basis of epidemiological and clinical data from tumor material as well as from in vitro data it has been suggested, that the HPV 16 E5 protein would have a function at the early stages of cervical carcinogenesis. The E5 protein enhances growth factor-mediated signal transduction to the nucleus and consequently augments cellular proliferation. Expression of the E5 protein enables the infected cell to escape growth control provided by surrounding cells by inhibiting gap junctional intercellular communication in epithelial cells. This viral oncogene seems to interfere with the control mechanisms of cellular growth and proliferation and thus facilitate the function of the E6 and E7 proteins and further steps towards epithelial cell transformation.     

Left-Atrial Appendage Thrombosis in Patients With Severe Aortic Stenosis Undergoing Transcatheter Aortic Valve Implantation

BackgroundData about the impact of left-atrial appendage thrombosis (LAAT) on early safety and mortality in patients undergoing transfemoral transcatheter aortic valve implantation (TF-TAVI) are scarce. We aimed to investigate the prevalence and predictors of LAAT and the outcome associated with this condition in patients treated by TF-TAVI.MethodsRetrospective data analysis was derived from a prospective single-centre registry comparing patients with and without LAAT regarding early safety at 30 days, according to Valve Academic Research Consortium-2 (VARC-2) and 2-year mortality.ResultsLAAT was found in 7.6% of the whole cohort (n = 2527) and in 16.6% in those patients with known pre-existing atrial fibrillation (AF cohort, n = 1099). Compared with controls, patients with LAAT were sicker, indicated by a higher Society of Thoracic Surgeons (STS) score and burden of comorbidities. Neither VARC-2–defined early safety at 30 days nor the rate of stroke was different between LAAT and controls in both the whole (early safety: 29.2% vs 24.2%, P = 0.123; stroke: 5.9% vs 4.7%, P = 0.495) and AF cohort (early safety: 29.1% vs 22.9%, P = 0.072; stroke: 5.6% vs 3.3%, P = 0.142). Evaluating the whole cohort in a univariate analysis, the 2-year mortality was significantly higher in LAAT compared with controls (hazard ratio, 1.41; 95% confidence interval, 1.07-1.86; P = 0.014). However, multivariate analysis of the whole cohort and the AF cohort revealed no association between LAAT and 2-year mortality.ConclusionsLAAT was frequent in patients undergoing TF-TAVI— in particular, in patients with histories of AF—but it was not associated with an increase in periprocedural complications and did not predict 2-year mortality.     

CTLA4 gene polymorphisms in Dutch and Chinese patients with inflammatory bowel disease

BACKGROUND: Inflammatory bowel diseases (IBDs) are characterized by chronic intestinal inflammation as a result of an exaggerated T-cell response. CTLA4, a receptor of activated T cells, has an inhibitory function in regulating T-cell activation. Since CTLA4 gene polymorphisms have been associated with several autoimmune diseases, the aim was to study these gene polymorphisms in patients with IBD in two different populations. METHODS: The C-318T polymorphism in the promoter region and A+49G polymorphism in exon I of the CTLA4 gene were investigated by a PCR-SSP method. We studied 139 unrelated patients with ulcerative colitis (UC), 163 patients with Crohn disease (CD) and 174 healthy controls of Dutch Caucasian origin as well as 35 patients with UC and 62 healthy controls from the Chinese Han population. RESULTS: No significant differences in the distribution of allele, genotype and haplotype frequencies were observed between C-318T and A+49G gene polymorphisms and IBD in Dutch Caucasians and UC in the Chinese Han population. Although the haplotypes of the C-318T and A+49G polymorphisms were distributed differently between Dutch Caucasian and Chinese Han populations, there were no differences in the subgroups of patients with CD classified according to age, localization and behaviour in the Vienna classification and in those with UC classified according to age at onset, disease extension and presence of colectomy in the Dutch patients. However, the CTLA4-318 genotype CC was more frequent in patients with CD over 40 years (93%) than in younger patients (74%) (P = 0.045). CONCLUSION: C-318T and A+49G CTLA4 gene polymorphisms and their haplotypes are not associated in Dutch Caucasian patients with IBD and in Chinese patients with UC.     

Susceptibility to ankylosing spondylitis: no evidence for the involvement of transforming growth factor beta 1 (TGFB1) gene polymorphisms

BACKGROUND: Genetic factors are thought to be crucial in the pathogenesis of ankylosing spondylitis. Transforming growth factor beta 1 (TGF beta 1) is a multifunctional cytokine that plays a key role in inflammation. Two functional single nucleotide polymorphisms (SNPs) in the TGFB1 gene have been described: TGFB1 T869C and TGFB1 G915C. OBJECTIVE: To determine whether these SNPs contribute to ankylosing spondylitis susceptibility or its disease characteristics. METHODS: Genomic DNA was isolated from the peripheral blood of 134 patients with ankylosing spondylitis and 194 healthy blood donors. All subjects were unrelated and of white Dutch ethnicity. The diagnosis of ankylosing spondylitis was made according to the modified New York criteria. The TGFB1 T869C and TGFB1 G915C SNPs were genotyped by a polymerase chain reaction-single strand conformation polymorphism haplotyping method. RESULTS: No significant differences were found between patients and controls in genotype, allele, and haplotype frequencies or in the carrier rate of the rare alleles of the TGFB1 T869C and TGFB1 G915C SNPs. CONCLUSIONS: TGFB1 T869C and TGFB1 G915C SNPs are not major factors in the susceptibility to ankylosing spondylitis or its disease characteristics.     

Combined carriership of TLR9-1237C and CD14-260T alleles enhances the risk of developing chronic relapsing pouchitis

AIM: To investigate the single nucleotide polymorphisms (SNPs) in genes involved in bacterial recognition and the susceptibility to pouchitis or pouchitis severity. METHODS: Analyses of CD14 -260C>T, CARD15/ NOD2 3020insC, Toll-like receptor (TLR)4 +896A>G, TLR9 -1237T>C, TLR9+2848G>A, and IRAKM + 22148G>A SNPs were performed in 157 Meal-pouch anal anastomosis (IPAA) patients (79 patients who did not develop pouchitis, 43 infrequent pouchitis patients, 35 chronic relapsing pouchitis patients) and 224 Italian Caucasian healthy controls. RESULTS: No significant differences were found in SNP frequencies between controls and IPAA patients. However, a significant difference in carriership frequency of the TLR9-1237C allele was found between the infrequent pouchitis and chronic relapsing pouchitis groups [P = 0.028, odd's ratio (OR) = 3.2, 95%d = 1.2-8.6]. This allele uniquely represented a 4-locus TLR9 haplotype comprising both studied TLR9 SNPs in Caucasians. Carrier trait analysis revealed an enhanced combined carriership of the alleles TLR9 -1237C and CD14 -260T in the chronic relapsing pouchitis and infrequent pouchitis group (P = 0.018, OR = 4.1, 95%CI = 1.4 -12.3). CONCLUSION: There is no evidence that the SNPs predispose to the need for IPAA surgery. The significant increase of the combined carriership of the CD14 -260T and TLR9 -1237C alleles in the chronic relapsing pouchitis group suggests that these markers identify a subgroup of IPAA patients with a risk of developing chronic or refractory pouchitis.     

Post‐mortem multiple sclerosis lesion pathology is influenced by single nucleotide polymorphisms

Over the last few decades, several common single nucleotide polymorphisms (SNPs) have been identified that correlate with clinical outcome in multiple sclerosis (MS), but the pathogenic mechanisms underlying the clinical effects of these SNPs are unknown. This is in part because of the difficulty in the functional translation of genotype into disease‐relevant mechanisms. Building on our recent work showing the association of clinical disease course with post‐mortem MS lesion characteristics, we hypothesized that SNPs that correlate with clinical disease course would also correlate with specific MS lesion characteristics in autopsy tissue. To test this hypothesis, 179 MS brain donors from the Netherlands Brain Bank MS autopsy cohort were genotyped for 102 SNPs, selected based on their reported associations with clinical outcome or their associations with genes that show differential gene expression in MS lesions. Three SNPs linked to MS clinical severity showed a significant association between the genotype and either the proportion of active lesions (rs2234978/FAS and rs11957313/KCNIP1) or the proportion of mixed active/inactive lesions (rs8056098/CLEC16A). Three SNPs linked to MS pathology‐associated genes showed a significant association with either proportion of active lesions (rs3130253/MOG), incidence of cortical gray matter lesions (rs1064395/NCAN) or the proportion of remyelinated lesions (rs5742909/CTLA4). In addition, rs2234978/FAS T‐allele carriers showed increased FAS gene expression levels in perivascular T cells and perilesional oligodendrocytes, cell types that have been implicated in MS lesion formation. Thus, by combining pathological characterization of MS brain autopsy tissue with genetics, we now start to translate genotypes linked to clinical outcomes in MS into mechanisms involved in MS lesion pathogenesis.     

Structural basis for the glucocorticoid response in a mutant human androgen receptor (AR(ccr)) derived from an androgen-independent prostate cancer

The crystal structure of a mutant androgen receptor (AR) ligand-binding domain (LBD) in complex with the agonist 9alpha-fluorocortisol has been determined at 1.95 A resolution. This mutant AR contains two mutations (L701H and T877A) and was previously reported as a high-affinity cortisol/cortisone responsive AR (AR(ccr)) isolated from the androgen-independent human prostate cancer cell lines MDA PCa 2a and 2b (Zhao et al. Nature Med. 2000, 6, 703-6). The three-dimensional structure of the AR(ccr) LBD complexed with 9alpha-fluorocortisol shows the typical conformation of an agonist-bound nuclear receptor in which helix 12 is precisely positioned as a "lid" for the ligand-binding pocket. Binding of 9alpha-fluorocortisol to the AR(ccr) involves favorable hydrogen bond patterns on the C17 and C21 substituents of the ligand due to the mutations at 701 and 877 in the AR(ccr). Our studies provide the first structural explanation for the glucocorticoid activation of AR(ccr), which is important for the development of new therapeutic treatments for androgen-independent prostate cancer.