3'-UTR OLR1/LOX-1 gene polymorphism and endothelial dysfunction: molecular and vascular data in never-treated hypertensive patients.

Endothelial dysfunction represents an independent predictor for clinical events. Genetic background may promote deleterious alterations of endothelial physiology. The aim of the study was to investigate the relationship between the rs1050283 polymorphism in the 3'-UTR of OLR1/LOX-1 gene and endothelial dysfunction in 178 never-treated hypertensive patients and 36 healthy subjects. The rs1050283 C/T single nucleotide polymorphism was detected, by TaqMan allelic discrimination assay. The influence of polymorphism on gene transcription rate was tested in 12 heterozygous hypertensive patients, by using an allelic imbalance assay. Forearm blood flow (FBF) was measured during intra-arterial infusion of acetylcholine (ACh), and sodium nitroprusside at increasing doses. Analysis of endothelium-dependent and endothelium-independent vasodilatation was tested according to rs1050283 polymorphism. In hypertensive patients, ACh-stimulated FBF is significantly reduced in T allele carriers (P < 0.0001), even when the allelic imbalance assay indicates an overexpression of C allele. In healthy subjects, there is no significant difference for ACh-dependent vasodilatation among genotypic groups (P = 0.660). In essential hypertensive patients, the T allele of OLR1/LOX-1 gene is strongly associated with an impaired endothelium-dependent vasodilatation, a powerful predictor of cardiovascular events.

Transabdominal coelocentesis as early source of fetal DNA for chromosomal and molecular diagnosis.

This study reports a comparative analysis between results of transabdominal coelocentesis and traditional invasive procedure in order to assess the usefulness of coelocentesis as a source of fetal DNA for molecular and chromosomal analysis. A number of 28 women were included in the study. A successful sampling of coelomic fluid was obtained in 25 women by transabdominal procedure. A positive amplification of DNA with QF-PCR techniques was obtained in 90% of cases, while 10% of cases failed to reveal interpretable results. Although all samples were cultured, the growth rate was not sufficient to determine karyotypes within 2 weeks. Five samples were selected to be analyzed by array-based comparative genomic hybridization (a-CGH) but the interpretation of these results was difficult and ambiguous. Our results suggest that transabdominal coelocentesis is suitable for the detection of single DNA variation and for QF-PCR analysis, while further experiments are needed to develop optimized protocols for traditional karyotyping and array-analysis.

IPLEX administration improves motor neuron survival and ameliorates motor functions in a severe mouse model of spinal muscular atrophy.

Spinal muscular atrophy (SMA) is an inherited neurodegenerative disorder and the first genetic cause of death in childhood. SMA is caused by low levels of survival motor neuron (SMN) protein that induce selective loss of α-motor neurons (MNs) in the spinal cord, resulting in progressive muscle atrophy and consequent respiratory failure. To date, no effective treatment is available to counteract the course of the disease. Among the different therapeutic strategies with potential clinical applications, the evaluation of trophic and/or protective agents able to antagonize MNs degeneration represents an attractive opportunity to develop valid therapies. Here we investigated the effects of IPLEX (recombinant human insulinlike growth factor 1 [rhIGF-1] complexed with recombinant human IGF-1 binding protein 3 [rhIGFBP-3]) on a severe mouse model of SMA. Interestingly, molecular and biochemical analyses of IGF-1 carried out in SMA mice before drug administration revealed marked reductions of IGF-1 circulating levels and hepatic mRNA expression. In this study, we found that perinatal administration of IPLEX, even if does not influence survival and body weight of mice, results in reduced degeneration of MNs, increased muscle fiber size and in amelioration of motor functions in SMA mice. Additionally, we show that phenotypic changes observed are not SMN-dependent, since no significant SMN modification was addressed in treated mice. Collectively, our data indicate IPLEX as a good therapeutic candidate to hinder the progression of the neurodegenerative process in SMA.

Cholesterol-lowering drugs inhibit lectin-like oxidized low-density lipoprotein-1 receptor function by membrane raft disruption.

Lectin-like oxidized low-density lipoprotein (LOX-1), the primary receptor for oxidized low-density lipoprotein (ox-LDL) in endothelial cells, is up-regulated in atherosclerotic lesions. Statins are the principal therapeutic agents for cardiovascular diseases and are known to down-regulate LOX-1 expression. Whether the effect on the LOX-1 receptor is related to statin-mediated cholesterol-lowering activity is unknown. We investigate the requirement of cholesterol for LOX-1-mediated lipid particle internalization, trafficking, and processing and the role of statins as inhibitors of LOX-1 function. Disruption of cholesterol-rich membrane microdomains by acute exposure of cells to methyl-ß-cyclodextrin or chronic exposure to different statins (lovastatin and atorvastatin) led to a spatial disorganization of LOX-1 in plasma membranes and a marked loss of specific LOX-1 function in terms of ox-LDL binding and internalization. Subcellular fractionation and immunochemical studies indicate that LOX-1 is naturally present in caveolae-enriched lipid rafts and, by cholesterol reduction, the amount of LOX-1 in this fraction is highly decreased (≥60%). In contrast, isoprenylation inhibition had no effect on the distribution and function of LOX-1 receptors. Furthermore, in primary cultures from atherosclerotic human aorta lesions, we confirm the presence of LOX-1 in caveolae-enriched lipid rafts and demonstrate that lovastatin treatment led to down-regulation of LOX-1 in lipid rafts and rescue of the ox-LDL-induced apoptotic phenotype. Taken together, our data reveal a previously unrecognized essential role of membrane cholesterol for LOX-1 receptor activity and suggest that statins protect vascular endothelium against the adverse effect of ox-LDL by disruption of membrane rafts and impairment of LOX-1 receptor function.