DNA methylation-associated colonic mucosal immune and defense responses in treatment-na?ve pediatric ulcerative colitis

Inflammatory bowel diseases (IBD) are emerging globally, indicating that environmental factors may be important in their pathogenesis. Colonic mucosal epigenetic changes, such as DNA methylation, can occur in response to the environment and have been implicated in IBD pathology. However, mucosal DNA methylation has not been examined in treatment-naïve patients. We studied DNA methylation in untreated, left sided colonic biopsy specimens using the Infinium HumanMethylation450 BeadChip array. We analyzed 22 control (C) patients, 15 untreated Crohn’s disease (CD) patients, and 9 untreated ulcerative colitis (UC) patients from two cohorts. Samples obtained at the time of clinical remission from two of the treatment-naïve UC patients were also included into the analysis. UC-specific gene expression was interrogated in a subset of adjacent samples (5 C and 5 UC) using the Affymetrix GeneChip PrimeView Human Gene Expression Arrays. Only treatment-naïve UC separated from control. One-hundred-and-twenty genes with significant expression change in UC (> 2-fold, P < 0.05) were associated with differentially methylated regions (DMRs). Epigenetically associated gene expression changes (including gene expression changes in the IFITM1, ITGB2, S100A9, SLPI, SAA1, and STAT3 genes) were linked to colonic mucosal immune and defense responses. These findings underscore the relationship between epigenetic changes and inflammation in pediatric treatment-naïve UC and may have potential etiologic, diagnostic, and therapeutic relevance for IBD.     

Biochemical responses and oxidative stress in <Emphasis Type="Italic">Francisella tularensis</Emphasis> infection: a European brown hare model

Background  

The aim of the present study was to investigate biochemical and oxidative stress responses to experimental F. tularensis infection in European brown hares, an important source of human tularemia infections.     

Ultrastructural and functional abnormalities of mitochondria in cultivated fibroblasts from α -mannosidosis patients

α-Mannosidosis is a lysosomal storage disorder caused by α-mannosidase deficiency. Clinical course of the disease ranges from severe infantile to milder juvenile type and includes mental retardation, skeletal deformities, coarse facies, hepatomegaly and hearing loss. The aim of the study was to analyse mitochondrial ultrastructure and function in cultivated fibroblasts from three patients with α-mannosidosis. All patients were homozygous for the c.2248C>T mutation in the MAN2B1 gene encoding lysosomal α-mannosidase. The mutation results in incorrect protein folding and severe decrease of α-mannosidase activity. The misfolded protein is retained by the control system of endoplasmic reticulum (ER). In analysed fibroblasts, we observed dilated ER, higher amount of aberrant mitochondria and reduced mitochondrial mass compared to controls. Respiratory chain complex IV, cytochrome c oxidase (COX), activity and the ratio between COX and citrate synthase (control enzyme) were significantly increased in comparison to controls (P < 0.05). Furthermore, the activity at least from one of other respiratory chain complexes was increased in each studied cell line. Mitochondrial membrane potential as well as reactive oxygen species production were comparable with controls. Based on our results, we hypothesize more profound effect of swelled and damaged mitochondria and ER dilatation on tissues with higher energy demand than fibroblasts have.     

Some Aspects of PCB Metabolism by Horseradish Cells

Transformation of polychlorinated biphenyls was studied using different strains of in vitro cultured cells of horseradish (Armoracia rusticana L.). Time and concentration dependence of this process and production of intracellular and extracellular peroxidases were measured with differentiated shooty teratoma culture K54. The yield of PCB transformation and the viability of the cells were highly dependent on PCB concentration. 100 ppm PCB totally inhibited growth of the cells, and reduced their metabolism of xenobiotics. Experiments with a peroxidase (POX) inhibitor, propylgallate, and a cytochrome P450 inhibitor, aminobenztriazole, indicated the involvement of both enzymatic systems in PCB metabolism.     

Interactions of 17β-Hydroxysteroid Dehydrogenase Type 10 and Cyclophilin D in Alzheimer's Disease

The nucleus-encoded 17β-hydroxysteroid dehydrogenase type 10 (17β-HSD10) regulates cyclophilin D (cypD) in the mitochondrial matrix. CypD regulates opening of mitochondrial permeability transition pores. Both mechanisms may be affected by amyloid β peptides accumulated in mitochondria in Alzheimer's disease (AD). In order to clarify changes occurring in brain mitochondria, we evaluated interactions of both mitochondrial proteins in vitro (by surface plasmon resonance biosensor) and detected levels of various complexes of 17β-HSD10 formed in vivo (by sandwich ELISA) in brain mitochondria isolated from the transgenic animal model of AD (homozygous McGill-R-Thy1-APP rats) and in cerebrospinal fluid samples of AD patients. By surface plasmon resonance biosensor, we observed the interaction of 17β-HSD10 and cypD in a direct real-time manner and determined, for the first time, the kinetic parameters of the interaction (k_a 2.0?×?10⁵ M¹s^?1, k_d 5.8?×?10⁴ s^?1, and K_D 3.5?×?10^–10 M). In McGill-R-Thy1-APP rats compared to controls, levels of 17β-HSD10–cypD complexes were decreased and those of total amyloid β increased. Moreover, the levels of 17β-HSD10–cypD complexes were decreased in cerebrospinal fluid of individuals with AD (in mild cognitive impairment as well as dementia stages) or with Frontotemporal lobar degeneration (FTLD) compared to cognitively normal controls (the sensitivity of the complexes to AD dementia was 92.9%, that to FTLD 73.8%, the specificity to AD dementia equaled 91.7% in a comparison with the controls but only 26.2% with FTLD). Our results demonstrate the weakened ability of 17β-HSD10 to regulate cypD in the mitochondrial matrix probably via direct effects of amyloid β. Levels of 17β-HSD10–cypD complexes in cerebrospinal fluid seem to be the very sensitive indicator of mitochondrial dysfunction observed in neurodegeneration but unfortunately not specific to AD pathology. We do not recommend it as the new biomarker of AD.