A Case of Compound Mutations in the MYBPC3 Gene Associated with Biventricular Hypertrophy and Neonatal Death

Hypertrophic cardiomyopathy (HCM) is a familial, genetically determined, primary cardiomyopathy caused by mutations in genes coding for proteins of the sarcomere, or, less frequently, genes involved in storage diseases. In pediatric settings, pure HCM has an estimated incidence of 4.7 per million children. The disease is often sub-clinical and goes unrecognized mainly because most patients with HCM have only mild symptoms, if any. However, sudden cardiac death, the most dramatic clinical occurrence and the primary concern for patients and physicians alike, may be the first manifestation of the disease. We describe a case of compound heterozygosity in the MYBPC3 gene (p.Glu258Lys and IVS25-1G>A) associated with biventricular hypertrophy, atrial enlargement and subsequent neonatal death 33 days postpartum. Other studies have reported compound and/or double heterozygosis in the same or different sarcomeric genes during childhood and adulthood, and neonatal presentations have also been described. Our observations show that the combination of a missense (p.Glu258Lys) and a splice-site mutation (IVS25-1G>A) profoundly affects the clinical course. In families in which parental mutations are known, preimplantation (where ethically and legally feasible) or prenatal genetic screening should be adopted because: (1) neonatal HCM in genetic heterozygosity is potentially lethal and (2) heart disease is the most common developmental malformation and the leading cause of neonatal mortality and morbidity.     

Steroid hormone regulation of C. elegans and Drosophila aging and life history

In the last two decades it has become clear that hormones and gene mutations in endocrine signaling pathways can exert major effects on lifespan and related life history traits in worms, flies, mice, and other organisms. While most of this research has focused on insulin/insulin-like growth factor-1 signaling, a peptide hormone pathway, recent work has shown that also lipophilic hormones play an important role in modulating lifespan and other life history traits. Here we review how steroid hormones, a particular group of lipophilic hormones, affect life history traits in the nematode worm (Caenorhabditis elegans) and the fruit fly (Drosophila melanogaster), with a particular focus on longevity. Interestingly, a comparison suggests that parallel endocrine principles might be at work in worms and flies in these species and that steroid hormones interact with the gonad to affect lifespan.     

Butyrate Induces Glutathione S-Transferase in Human Colon Cells and Protects From Genetic Damage by 4-Hydroxy-2-Nonenal

Butyrate, one of the major products of gut fermentation, is known to inhibit proliferation, induce apoptosis and differentiation, and increase phase II enzyme activities in tumor cells, whereas little information is available on protective effects in less-transformed colon cells. The aim of this study was to investigate whether the chemoprotective mechanism of glutathione S-transferase (GST) induction by butyrate could also play a role in earlier stages of colon carcinogenesis and whether chemoresistance of cells toward the endogenous genotoxic risk factor 4-hydroxy-2-nonenal (HNE) could be a consequence of butyrate treatment. As cell models, we used the human tumor cell lines HT29 and HT29 clone 19A, a differentiated subclone with properties resembling primary colon cells. We determined the expression of GSTP1 protein (enzyme-linked immunosorbent assay), the major GST in HT29, GSTP1 mRNA (Northern blotting), GST activity, intracellular glutathione, and total protein. The genotoxic impact of HNE (100-200 μM) was compared in butyrate-treated and nontreated cells using single-cell microgel electrophoresis. Our results show that GSTP1 mRNA, GSTP1 protein, GST activity, and total protein were increased (1.2- to 2.5-fold) and glutathione levels were maintained after 24- 72 h of incubation with 4 mM butyrate. Moreover, a marked reduction of HNE-induced genotoxicity was caused by preincubation with butyrate. Butyrate also induced the phosphorylation of extracellular signal-regulated kinases (ERK1/2, Western blotting) after 5-30 min, which indicates a regulation of GST expression by this signal pathway. Most effects were greater in HT29 parent cells than in clone cells. In conclusion, butyrate enhances expression of GST and other proteins in both cell lines, which leads to an enhanced chemoprotection, reducing the impact of HNE genotoxicity. Thus butyrate could play a role in early and later stages of cancer prevention by reducing exposure to relevant risk factors.     

Intraventricular entrapment of a Sapien-3 balloon in transapical TAVR: A near missed catastrophe

Balloon rupture is an uncommon complication during balloon-expandable transcatheter aortic valve replacement (TAVR). We describe a balloon rupture and tearing with intraventricular entrapment complicating transapical-TAVR, as well as our bailout retrieval of the failed device.     

Association between Body Iron Status and Leukocyte Telomere Length,a Biomarker of Biological Aging,in a Nationally Representative Sample of US Adults

Background

Excess iron levels can induce oxidative stress and could therefore affect telomere attrition. However, little is known about the impact of body iron status on telomere length.