Molecular phenotype of right ventricular hypertrophy in human tetralogy of Fallot

In 1888 the French physician Etienne-Louis Arthur Fallot described a “tetrad” of congenital anatomical defects in a heart, which are now collectively referred to as tetralogy of Fallot (TF). TF is characterized by a (sub)valvular pulmonary stenosis, a ventricular septal defect (VSD), dextroposition of the aorta (overriding the VSD) and concomitant right ventricular hypertrophy (RVH) (Fig. 1.1). The right ventricular (RV) outflowtract obstruction can be more or less severe, depending on the degree of malformation as well as the extent of RVH. With an incidence of 1 per 2000 newborns TF is a frequent cyanotic congenital heart malformation

Quantitative analysis of collagens and fibronectin expression in human right ventricular hypertrophy

One of the main features in human tetralogy of Fallot (TF) is right ventricular hypertrophy (RVH) due to pressure (sub-pulmonary stenosis) and volume overload (ventricular septal defect). Currently, primary correction at a young age is the treatment of choice. To unravel the role of extracellular matrix in RVH, we examined myocardial expression of collagens and fibronectin in TF patients with primary correction (TF1, age 0.7 ± 0.2 yr,), secondary surgery (TF2, age 36.9 ± 4.6 yr), and in age-matched control patients. Sirius red staining quantified by video imaging showed significantly increased interstitial staining for collagens in both TF1 and TF2 groups as compared to respective controls. Fibronectin was expressed in extracellular spaces, perivascular regions, and in some cardiomyocytes. Quantitative analysis of fibronectin revealed increased expression in only TF1 group as compared to respective control. Our results indicate an increased amount of myocardial extracellular matrix deposition as a sign of fibrosis during RVH in patients with TF

Differences in the early response of hatchlings of different chicken breeding lines to Salmonella enterica serovar Enteritidis infection

Poultry products are the major source of food-borne Salmonella infection in humans. Broiler lines selected to be more resistant to Salmonella could reduce the transfer of Salmonella to humans. To investigate differences in the susceptibility of newly hatched chicks to oral infection with Salmonella enterica serovar Enteritidis, 3 commercial broiler lines (A, B, and C) were infected immediately after hatch and compared to healthy controls at 0.33, 1, and 2 d postinfection. Weight, bacteriological examination, and the jejunal influx of CD4, CD8, TCRaß, TCR¿d, and KUL01 (macrophages and dendritic cells) cells that are positive was investigated. In addition, the jejunal transcriptional response was analyzed using whole-genome chicken cDNA arrays. Salmonella colony-forming unit counts from cecal content and liver revealed that Salmonella enterica entered the body at 0.33 d postinfection. Broiler line A appeared most susceptible to intestinal colonization and the systemic spread of Salmonella. In addition, the Salmonella-induced jejunal influx of macrophages in this line showed a clear increase in time, which is in contrast to lines B and C. On the other hand, all lines showed a peak of CD4+ cells at 1 d postinfection when infected chicks were compared to control chicks. The transcriptional response of line A clearly differed from the responses in lines B and C. Functional analysis indicated that the majority of the differentially expressed genes at 0.33 d postinfection in line A were involved in cell-cycle functions, whereas at 2 d postinfection the majority of the differentially expressed genes could be assigned to inflammatory disorder, differentiation and proliferation of (T) lymphocytes. These data indicate that hatchlings of different broiler lines differ in their systemic spread of Salmonella and suggest that intestinal barrier functions, as well as immunological responses, may be the underlying factors. We hypothesize that the differences between genetic chicken lines divergent in their response to Salmonella infection at a young age include developmental differences of the gut

DNA Microarray and Quantitative Analysis Reveal Enhanced Myocardial VEGF Expression with Stunted Angiogenesis in Human Tetralogy of Fallot

Tetralogy of Fallot (ToF) is a cyanotic congenital heart disease with prominent right ventricular hypertrophy (RVH) associated with impaired myocardial oxygen and nutrient supply. Consequently, the right ventricle may manifest in altered molecular phenotype with a number of adaptive and inherited gene profiles which are largely unknown. The aim of the present study was to investigate the myocardial differential gene expression profile and to assess myocardial vascularisation in patients with ToF. DNA microarray analysis on right ventricular biopsies from ToF-patients operated for primary corrective surgery (referred as ToF-1; n = 12, mean age 0.5 year) and age matched controls (n = 6) was validated by Northern hybridisation and RT-PCR. Employing immunohistochemistry and video image analysis expression of vascular endothelial growth factor (VEGF), vascular density (by alpha-SMA and CD31 staining) and myocyte cross sectional area (Gomori's reticuline staining) were assessed in ToF-1 and adult patients (referred as ToF-2, n = 12, mean age 30 years) who underwent surgery for pulmonary regurgitation and compared the data with respective age matched controls (n = 6/12). DNA microarray analysis revealed altered expression pattern for 236 genes including enhanced (1.5-2.2-fold) expression of angiogenic factors and their receptors including; VEGF, flt-1, flk-1 angiopoietin-2, FGF-2, FGF-R1, PDGF-A, whereas, flt-4, Tie, TGF-beta, TGF-beta 3R showed decreased (1.6-3.4-fold) expression in ToF-patients. Northern blot analysis verified the expression patterns of VEGF and flk-1 in both ToF-1 and ToF-2 patients. VEGF staining in cardiomyocytes was increased in ToF-1 (1.5-fold, p < 0.05) as compared to ToF-2. Video image analysis revealed enhanced vascular density (p < 0.01) with enlarged myocyte cross sectional area (p < 0.01), but vascular wall thickness remained unchanged in ToF-1 patients as compared to age matched controls. Our data suggest that RVH is associated with profound changes in gene profile for a number of genes, where VEGF/VEGF-R system contributes to enhance, but stunted myocardial angiogenesis in patients with ToF

Lifestyle of lactobacillus plantarum in the mouse cecum

Lactobacillus plantarum is a common inhabitant of mammalian gastrointestinal tracts and specific strains belonging to this species are marketed as probiotics intended to confer beneficial health effects. To assist in determining the physiological status and host-microbe interactions of L. plantarum in the digestive tract we assessed changes in the transcriptome of L. plantarum WCFS1 during colonization of the cecum of germ-free mice. According to the transcript profiles L. plantarum WCFS1 was metabolically active and not under severe stress in this intestinal compartment. Carbohydrate metabolism was the most strongly affected functional gene category whereby many genes encoding diverse sugar transport and degradation pathways were induced in mice even compared to L. plantarum grown in a mouse chow-derived laboratory medium. This suggests that the ability of L. plantarum WCFS1 to consume diverse energy sources including plant-associated and host-derived carbohydrates was increased during its residence in the digestive tract. Many of these genes were also induced in L. plantarum colonizing germ-free mice fed a humanized Western-style diet. Similarly a core set of genes encoding cell surface-related properties were differentially expressed in mice. This set includes genes required for the D-alanylation and glycosylation of lipoteichoic acids that were strongly down-regulated in mice. In total L. plantarum exhibits a distinct in vivo transcriptome directed towards adaptation to the mouse intestinal environment

Lifestyle of lactobacillus plantarum in the mouse cecum

Lactobacillus plantarum is a common inhabitant of mammalian gastrointestinal tracts and specific strains belonging to this species are marketed as probiotics intended to confer beneficial health effects. To assist in determining the physiological status and host-microbe interactions of L. plantarum in the digestive tract we assessed changes in the transcriptome of L. plantarum WCFS1 during colonization of the cecum of germ-free mice. According to the transcript profiles L. plantarum WCFS1 was metabolically active and not under severe stress in this intestinal compartment. Carbohydrate metabolism was the most strongly affected functional gene category whereby many genes encoding diverse sugar transport and degradation pathways were induced in mice even compared to L. plantarum grown in a mouse chow-derived laboratory medium. This suggests that the ability of L. plantarum WCFS1 to consume diverse energy sources including plant-associated and host-derived carbohydrates was increased during its residence in the digestive tract. Many of these genes were also induced in L. plantarum colonizing germ-free mice fed a humanized Western-style diet. Similarly a core set of genes encoding cell surface-related properties were differentially expressed in mice. This set includes genes required for the D-alanylation and glycosylation of lipoteichoic acids that were strongly down-regulated in mice. In total L. plantarum exhibits a distinct in vivo transcriptome directed towards adaptation to the mouse intestinal environment