Connective tissue growth factor (CTGF) is a secreted protein that is strongly induced in human and experimental heart failure. CTGF is said to be profibrotic; however, the precise function of CTGF is unclear. We generated transgenic mice and rats with cardiomyocyte-specific CTGF overexpression (CTGF-TG). To investigate CTGF as a fibrosis inducer, we performed morphological and gene expression analyses of CTGF-TG mice and rat hearts under basal conditions and after stimulation with angiotensin II (Ang II) or isoproterenol, respectively. Surprisingly, cardiac tissues of both models did not show increased fibrosis or enhanced gene expression of fibrotic markers. In contrast to controls, Ang II treated CTGF-TG mice displayed preserved cardiac function. However, CTGF-TG mice developed age-dependent cardiac dysfunction at the age of 7 months. CTGF related heart failure was associated with Akt and JNK activation, but not with the induction of natriuretic peptides. Furthermore, cardiomyocytes from CTGF-TG mice showed unaffected cellular contractility and an increased Ca2+ reuptake from sarcoplasmatic reticulum. In an ischemia/reperfusion model CTGF-TG hearts did not differ from controls.Our data suggest that CTGF itself does not induce cardiac fibrosis. Moreover, it is involved in hypertrophy induction and cellular remodeling depending on the cardiac stress stimulus. Our new transgenic animals are valuable models for reconsideration of CTGF's profibrotic function in the heart.

BackgroundOstium secundum atrial septal defects (ASDII) account for approximately 10% of all congenital heart defects (CHD), and mutations in cardiac transcription factors, including TBX20, were identified as an underlying cause for ASDII. However, very little is known about disease penetrance in families and functional consequences of inherited TBX20 mutations.MethodsThe coding region of TBX20 was directly sequenced in 170 ASDII patients. Functional consequences of one novel mutation were investigated by surface plasmon resonance, CD spectropolarymetry, fluorescence spectrophotometry, luciferase assay and chromatin immunoprecipitation.ResultsWe found a novel mutation in a highly conserved residue in the T-box DNA binding domain (I121M) segregating with CHD in a three generation kindred. Four mutation carriers revealed cardiac phenotypes in terms of cribriform ASDII, large patent foramen ovale or cardiac valve defects. Interestingly, tertiary hydrophobic interactions within the mutant TBX20 T-box were significantly altered leading to a more dynamic structure of the protein. Moreover, Tbx20-I121M resulted in a significantly enhanced transcriptional activity, which was further increased in the presence of co-transcription factors GATA4/5 and NKX2-5. Occupancy of DNA binding sites on target genes was also increased.ConclusionsWe suggest that TBX20-I121M adopts a more fluid tertiary structure leading to enhanced interactions with cofactors and more stable transcriptional complexes on target DNA sequences. Our data, combined with that of others, suggest that human ASDII may be related to loss-of-function as well as gain-of-function TBX20 mutations.

The familial form of dilated cardiomyopathy (DCM) occurs in about 20%-50% of DCM cases. It is a heterogeneous genetic disease: mutations in more than 20 different genes have been shown to cause familial DCM. LMNA, encoding the nuclear membrane protein lamin A/C, is one of the most important disease gene for that disease. Therefore, we analyzed the LMNA gene in a large cohort of 73 patients with familial DCM. Clinical examination (ECG, echocardiography, and catheterization) was followed by genetic characterization of LMNA by direct sequencing. We detected five heterozygous missense mutations (prevalence 7%) in five different families characterized by severe DCM and heart failure with conduction system disease necessitating pacemaker implantation and heart transplantation. Four of these variants clustered in the protein domain coil 1B, which is important for lamin B interaction and lamin A/C dimerization. Although we identified two novel mutations (E203V, K219T) besides three known ones (E161K, R190Q, R644C), it was remarkable that four mutations represent LMNA hot spots. DCM patients with LMNA mutations show a notable homogenous severe phenotype as we could confirm in our study. Testing LMNA in such families seems to be recommended because genotype information in an individual could definitely be useful for the clinician.

Objectives: Increased intracranial pressure (ICP) in neonates and infants is a severe disease state that requires adequate diagnosis and, depending on the clinical situation and whether it is increasing, a rapid and efficient therapy. Clinical evaluation, B-mode ultrasound, and Doppler ultrasound give rise to a basic noninvasive diagnosis of increased ICP. The purpose of this prospective study was 2-fold: first, to analyze the technical feasibility of obtaining shear wave elastography (SWE) measurements of an infant's brain, and second, to compare the values of healthy neonates to those who have hydrocephalus and are either suspected of having or invasively shown to have increased ICP. Materials and Methods: This was a prospective, institutional review boardapproved study of 184 neonates and infants with a mean age of 12 weeks (ranging from 1 day to 12 months). The final, technical evaluable cohort consisted of 166 infants, of whom 110 were healthy asymptomatic infants and 56 were diagnosed with hydrocephalus. Of the latter, 38 showed clinically increased ICP and 18 did not. Invasive ICP measurements were available from 47 of the children. All infants underwent systematic examination using B-mode ultrasound, Doppler ultrasound, and SWE using a high-resolution linear 15-MHz probe (Aixplorer; Supersonic), by 1 of 2 radiologists, each of whom had at least 5 years' experience examining children's brains and applying SWE. Semiquantitative and quantitative SWE measurements were performed.We compared the SWE values to each participant's clinical symptoms and to their invasive ICP measurement results. Correlations were calculated using Pearson and Spearman correlation coefficients. We used Student t test to compare the mean SWE values in healthy children to those of children with increased ICP. Results: Shear wave elastography in the brain was technically feasible, giving reliable SWE measurements in 110 (88.7%) of 124 of healthy children and in 56 (93.3%) of 60 children with hydrocephalus. Shear wave elastography values and, thus, rigidity in the brain's parenchyma were significantly higher in children with hydrocephalus (n = 56) than in healthy children (n = 110; mean, 21.8 kPa vs 14.1 kPa; P = 0.0083). A thorough correlation between invasive ICP measurements and SWE values in a subgroup of patients with hydrocephalus revealed a direct correlation between increased ICP and increased SWE values (r = 0.69, P < 0.001). Mean SWE values were 30.8 kPa (range, 23.9-62.3 kPa) in patients with confirmed increased ICP (n = 35) versus 16.2 kPa (range, 10.2-41.9 kPa) in patients with nonincreased ICP (n = 12). Conclusions: Shear wave elastography is feasible in neonates with increased ICP and could be a useful additional diagnostic imaging and monitoring method for children verified or suspected to have increased ICP. However, more evidence is necessary to further evaluate the usefulness of SWE measurements in neonates with hydrocephalus. Clinical Relevance: Shear wave elastography can be used as a surrogate marker for ICP in neon...