Pulse-chase studies of [3S]cysteine-labeled fibrillin were performed on fibroblast strains from 55 patients with Marfan syndrome (MFS), including 13 with identified mutations in the fibrillin-1 gene and 10 controls. Quantitation of the soluble intracellular and insoluble extraceliular fibrillin allowed discrimination of five groups. Groups I (n = 8) and H (n = 19) synthesize reduced amounts of normal-sized fibrillin, while synthesis is normal in groups m (n = 6), IV (n = 18), and V (n = 4). When extracellular fibrillin deposition is measured, groups I and III deposit between 35 and 70% of control values, groups II and IV < 35%, and group V > 70%.A deletion mutant with a low transcript level from the mutant allele and seven additional patients have the group I protein phenotype. Disease in these patients is caused by a reduction in microfibrils associated with either a null allele, an unstable transcript, or an altered fibrillin product synthesized in low amounts. In 68% of the MFS individuals (groups II and IV), a dominant negative effect is invoked as the main pathogenetic mechanism. Products made by the mutant allele in these fibroblasts are proposed to interfere with microfibril formation. Insertion, deletion, and exon skipping mutations, resulting in smaller fibrillin products, exhibit the group II phenotype. A truncated form of fibrillin of 60 kD was identified with specific fibrillin antibodies in one of the group II cell culture media. Seven of the nine known missense mutations, giving rise to abnormal, but normal-sized fibrillin molecules, are in group IV. (J. Clin. Invest. 1994. 94:130-137.) Key words: fibrillin biosynthesis e dominant negative mutation * FBNJ * extracellular matrix * elastin-associated microfibril

Both TIMPs and MMP-2 remained inactive during hypertrophy, per se; they were activated during the transition to CHF. At this time, the activation of MMP-2 surpassed that of TIMPs, possibly resulting in ECM breakdown and progression of LV enlargement.

Background: Despite recommendations in the guidelines and consensus documents, there has been no randomized controlled trial evaluating oral anticoagulation (OAC) alone without antiplatelet therapy (APT) in patients with atrial fibrillation and stable coronary artery disease beyond 1 year after coronary stenting. Methods: This study was a prospective, multicenter, open-label, noninferiority trial comparing OAC alone to combined OAC and single APT among patients with atrial fibrillation beyond 1 year after stenting in a 1:1 randomization fashion. The primary end point was a composite of all-cause death, myocardial infarction, stroke, or systemic embolism. The major secondary end point was a composite of the primary end point or major bleeding according to the International Society on Thrombosis and Haemostasis classification. Although the trial was designed to enroll 2000 patients during 12 months, enrollment was prematurely terminated after enrolling 696 patients in 38 months. Results: Mean age was 75.0±7.6 years, and 85.2% of patients were men. OAC was warfarin in 75.2% and direct oral anticoagulants in 24.8% of patients. The mean CHADS 2 score was 2.5±1.2. During a median follow-up interval of 2.5 years, the primary end point occurred in 54 patients (15.7%) in the OAC-alone group and in 47 patients (13.6%) in the combined OAC and APT group (hazard ratio, 1.16; 95% CI, 0.79–1.72; P =0.20 for noninferiority, P =0.45 for superiority). The major secondary end point occurred in 67 patients (19.5%) in the OAC-alone group and in 67 patients (19.4%) in the combined OAC and APT group (hazard ratio, 0.99; 95% CI, 0.71–1.39; P =0.016 for noninferiority, P =0.96 for superiority). Myocardial infarction occurred in 8 (2.3%) and 4 (1.2%) patients, whereas stroke or systemic embolism occurred in 13 (3.8%) and 19 (5.5%) patients, respectively. Major bleeding occurred in 27 (7.8%) and 36 (10.4%) patients, respectively. Conclusions: This randomized trial did not establish noninferiority of OAC alone to combined OAC and APT in patients with atrial fibrillation and stable coronary artery disease beyond 1 year after stenting. Because patient enrollment was prematurely terminated, the study was underpowered and inconclusive. Future larger studies are required to establish the optimal antithrombotic regimen in this population. Clinical Trial Registration: URL: https://www.clinicaltrials.gov . Unique identifier: NCT01962545.

Transforming growth factor-beta1 (TGF-beta1) alters myocardial gene expression, resulting in myocyte hypertrophy, through activation of TGF-beta-activated kinase (TAK1), a member of the mitogen-activated protein kinase kinase kinase (MAPKKK) family. We hypothesized that the TGF-beta1-TAK1-p38 MAPK pathway might be activated during ventricular remodeling after myocardial infarction (MI). One, 3, 7, and 14 days after ligation of the left anterior descending coronary artery, noninfarcted left ventricular tissue samples were obtained. Protein levels as well as mRNA levels of the signaling pathway, TGF-beta1, TGF-beta-receptors, and TAK1 increased in the noninfarcted myocardium in MI rats compared with sham-operated animals. Phosphorylation of MAPKK 3/6 (MKK3/6) and p38 MAPK, the downstream targets of TAK1, was also increased in the noninfarcted region. Moreover, an in vitro kinase assay revealed that the activated TAK1 in the noninfarcted myocardium was capable of activating recombinant MKK3/6, suggesting a causative role of TAK1 in the remodeling process. The activation of the TGF-beta1-TAK1-p38 MAPK pathway paralleled the transcriptional upregulation of cardiac markers for ventricular hypertrophy, beta-myosin heavy chain and atrial natriuretic peptide. TAK1 was mainly localized to cardiomyocytes, whereas TGF-beta1 receptors were observed in vascular smooth muscle cells and fibroblasts as well as cardiomyocytes. Thus the TGF-beta1-TAK1-MKK3/6-p38 MAPK pathway in the cardiomyocytes of noninfarcted spared myocardium is activated after acute MI and may play an important role in ventricular hypertrophy and post-MI remodeling in rats.

Nitric oxide accounts for the activity of endothelium-derived relaxing factor, which seems to have an important role in vasodilation and inhibition of platelet aggregation. In endothelial cells, one isoform of nitric-oxide synthase is constitutively expressed. Analysis of the cDNA encoding the human endothelial nitric-oxide synthase revealed that the mRNA is 4.1 kb in size and that the translated protein consists of 1203 amino acids. We have cloned a genomic DNA encoding the human endothelial nitric-oxide synthase and analyzed the entire nucleotide sequence of the gene. The gene consists of 26 exons with a total size of 21 kb. The 5' flanking region of the gene lacks TATA boxes, but it contains putative Spl-binding sites in (G+C)-rich regions. Of particular interest is the fact that a shear-stress-responsive element is located at position -985, which probably regulates the nitric-oxide-synthase gene in response to fluid mechanical forces at the transcriptional level in the vascular endothelium. Two minisatellite sequences are detectable in introns 2 and 8; a 32-bp consensus sequence repeats 38 times and a 57-bp consensus sequence repeats ten times. We found polymorphisms of the BarnHI fragment containing the former minisatellite sequence in genomic DNA from pedigree family members. Furthermore, five tandem repeats of a 27-bp core consensus sequence and 35 repeats of a dinucleotide (CA) are located in introns 4 and 13, respectively. These repeat sequences will probably provide genetic markers for gene mapping and linkage analysis of inherited diseases including cardiovascular diseases.Nitric oxide has been recently implicated in a number of diverse physiological processes, including smooth muscle relaxation, inhibition of platelet aggregation, neurotransmission, immune regulation and penile erection 11, 21. Nitric oxide is produced from L-arginine by nitric-oxide synthase with a concomitant production of L-citrulline. There appears to be at least three distinct isoforms of nitric-oxide synthase [l-41. All three isoforms contain consensus sequences for the binding of FMN, FAD, and NADPH cofactors, and the structures of the isoforms have close homology to cytochrome P-450 reductase 11, 2, 51.Endothelium-derived relaxing factor 161 is important in the regulation of vasomotor tone and blood flow by inhibiting smooth muscle contraction and platelet aggregation [7]. Recently, several groups reported that nitric oxide accountsCorrespondence to