Pendred syndrome (PDS) and DFNB4 comprise a phenotypic spectrum of sensorineural hearing loss disorders that typically result from biallelic mutations of the SLC26A4 gene. Although PDS and DFNB4 are recessively inherited, sequencing of the coding regions and splice sites of SLC26A4 in individuals suspected to be affected with these conditions often fails to identify two mutations. We investigated the potential contribution of large SLC26A4 deletions and duplications to sensorineural hearing loss (SNHL) by screening 107 probands with one known SLC26A4 mutation by Multiplex Ligation-dependent Probe Amplification (MLPA). A heterozygous deletion, spanning exons 4-6, was detected in only one individual, accounting for approximately 1% of the missing mutations in our cohort. This low frequency is consistent with previously published MLPA results. We also examined the potential involvement of digenic inheritance in PDS/DFNB4 by sequencing the coding regions of FOXI1 and KCNJ10. Of the 29 probands who were sequenced, three carried nonsynonymous variants including one novel sequence change in FOXI1 and two polymorphisms in KCNJ10. We performed a review of prior studies and, in conjunction with our current data, conclude that the frequency of FOXI1 (1.4%) and KCNJ10 (3.6%) variants in PDS/DFNB4 individuals is low. Our results, in combination with previously published reports, indicate that large SLC26A4 deletions and duplications as well as mutations of FOXI1 and KCNJ10 play limited roles in the pathogenesis of SNHL and suggest that other genetic factors likely contribute to the phenotype.
Summary Endothelial cell adhesion molecules orchestrate the recruitment and binding of inflammatory cells to vascular endothelium. With endothelial dysfunction and vascular injury, the levels of endothelial bound and soluble adhesion molecules increase. Such expression is modulated by nitric oxide (NO), and in patients with sickle cell disease (SCD), these levels are inversely associated with measures of NO bioavailability. To further evaluate the role of endothelial dysfunction in a population study of SCD, we have measured the levels of soluble endothelium‐derived adhesion molecules in the plasma specimens of 160 adult patients with SCD during steady state. Consistent with a link between endothelial dysfunction and end‐organ disease, we found that higher levels of soluble vascular cell adhesion molecule‐1 (sVCAM‐1) were associated with markers indicating renal dysfunction and hepatic impairment. Analysis of soluble intercellular cell adhesion molecule‐1 (sICAM‐1), sE‐selectin and sP‐selectin levels indicated partially overlapping associations with sVCAM‐1, with an additional association with inflammatory stress and triglyceride levels. Importantly, increased soluble adhesion molecule expression correlated with severity of pulmonary hypertension, a clinical manifestation of endothelial dysfunction. Soluble VCAM‐1, ICAM‐1, and E‐selectin were independently associated with the risk of mortality in this cohort. Our data are consistent with steady state levels of soluble adhesion molecules as markers of pulmonary hypertension and risk of death.
Abstract —Atherosclerotic lesion development is characterized by the recruitment of leukocytes, principally monocytes, to the vessel wall. Considerable interest has been focused on the adhesion molecule(s) involved in leukocyte/endothelial interactions. The goal of the present study was to determine the role of the very late antigen-4 (VLA-4) integrin/ligand interaction in fatty streak development using murine models. Because α4 null mice are not viable, a peptidomimetic was used to block VLA-4–mediated leukocyte binding. The ability of a synthetic peptidomimetic of connecting segment-1 (CS-1 peptide) to block the recruitment of leukocytes and the accumulation of lipid in the aortic sinus of either wild-type mice (strain C57BL/6J) or mice with a low-density lipoprotein null mutation (LDLR−/−) maintained on an atherogenic diet was assessed. The active (Ac) CS-1 peptide or scrambled (Sc) CS-1 peptide was delivered subcutaneously into mice using a mini osmotic pump. Mice were exposed to the peptide for 24 to 36 hours before the onset of the atherogenic diet. In C57BL/6J mice, leukocyte entry into the aortic sinus, as assessed by en face preparations, was inhibited by the active peptide (Ac=28±4, Sc=54±6 monocytes/valve; P =0.004). Additionally, frozen sections stained with Oil Red O were analyzed to assess lipid accumulation in the aortic sinus. C57BL/6J mice that received the (Ac) compound demonstrated significantly reduced lesion areas as compared with mice that received the (Sc) peptide (Ac=4887±4438 μm 2 , Sc=15 009 ±5619 μm 2 ; P <0.0001). In a separate study, LDLR−/− mice were implanted with pumps containing either the (Ac) or (Sc) peptide before initiation of the atherogenic diet. Because LDLR−/− mice fed a chow diet displayed small lesions at 14 weeks, the effects of the peptide seen in these animals represented a change in early lipid accumulation rather than initiation. By using whole-mount preparations, the (Ac) but not the (Sc) peptide significantly reduced the area of lipid accumulation in the aortic sinus, resulting in an approximate 66% decrease. Plasma analysis from all studies revealed concentrations of peptide to be present at levels previously determined by in vitro analysis to block adhesion. (Ac) CS-1 peptide, which blocks VLA-4 on the leukocyte surface, is effective in reducing leukocyte recruitment and lipid accumulation in the aortic sinus. The present study provides in vivo evidence that the VLA-4 integrin plays an important role in the initiation of the atherosclerotic lesion and lipid accumulation, and it suggests a potential therapeutic strategy for this disease.
Brennan, Marie-Luise; Penn, Marc S.; Van Lente, Frederick; Nambi, Vijay; Shishenbor, Mehdi H.; Aviles, Ronnier J.; Goormastic, Marlene; Pepoy, Michael L.; McErlean, Ellen S.; Topol, Eric J.; Nissen, Steven E.; Hazen, Stanley L.
Pendred syndrome (PDS) and DFNB4 comprise a phenotypic spectrum of sensorineural hearing loss disorders that typically result from biallelic mutations of the SLC26A4 gene. Although PDS and DFNB4 are recessively inherited, sequencing of the coding regions and splice sites of SLC26A4 in individuals suspected to be affected with these conditions often fails to identify two mutations. We investigated the potential contribution of large SLC26A4 deletions and duplications to sensorineural hearing loss (SNHL) by screening 107 probands with one known SLC26A4 mutation by Multiplex Ligation-dependent Probe Amplification (MLPA). A heterozygous deletion, spanning exons 4-6, was detected in only one individual, accounting for approximately 1% of the missing mutations in our cohort. This low frequency is consistent with previously published MLPA results. We also examined the potential involvement of digenic inheritance in PDS/DFNB4 by sequencing the coding regions of FOXI1 and KCNJ10. Of the 29 probands who were sequenced, three carried nonsynonymous variants including one novel sequence change in FOXI1 and two polymorphisms in KCNJ10. We performed a review of prior studies and, in conjunction with our current data, conclude that the frequency of FOXI1 (1.4%) and KCNJ10 (3.6%) variants in PDS/DFNB4 individuals is low. Our results, in combination with previously published reports, indicate that large SLC26A4 deletions and duplications as well as mutations of FOXI1 and KCNJ10 play limited roles in the pathogenesis of SNHL and suggest that other genetic factors likely contribute to the phenotype.
Pendred syndrome (PDS) and DFNB4 comprise a phenotypic spectrum of sensorineural hearing loss disorders that typically result from biallelic mutations of the SLC26A4 gene. Although PDS and DFNB4 are recessively inherited, sequencing of the coding regions and splice sites of SLC26A4 in individuals suspected to be affected with these conditions often fails to identify two mutations. We investigated the potential contribution of large SLC26A4 deletions and duplications to sensorineural hearing loss (SNHL) by screening 107 probands with one known SLC26A4 mutation by Multiplex Ligation-dependent Probe Amplification (MLPA). A heterozygous deletion, spanning exons 4–6, was detected in only one individual, accounting for approximately 1% of the missing mutations in our cohort. This low frequency is consistent with previously published MLPA results. We also examined the potential involvement of digenic inheritance in PDS/DFNB4 by sequencing the coding regions of FOXI1 and KCNJ10. Of the 29 probands who were sequenced, three carried nonsynonymous variants including one novel sequence change in FOXI1 and two polymorphisms in KCNJ10. We performed a review of prior studies and, in conjunction with our current data, conclude that the frequency of FOXI1 (1.4%) and KCNJ10 (3.6%) variants in PDS/DFNB4 individuals is low. Our results, in combination with previously published reports, indicate that large SLC26A4 deletions and duplications as well as mutations of FOXI1 and KCNJ10 play limited roles in the pathogenesis of SNHL and suggest that other genetic factors likely contribute to the phenotype.
Detection of an optimal panel of biomarkers capable of predicting a patient's risk of major adverse cardiac events (MACE) is of clinical significance. Due to the high dynamic range of the protein concentration in human blood, applying proteomics techniques for protein profiling can generate large arrays of data for development of optimized clinical biomarker panels. The objective of this study is to discover a panel of biomarkers for predicting risk of MACE in subjects reliably. The development of immunoassay can only tolerate the complexity of the prediction model with less than ten selected biomarkers. Hence, traditional optimization methods, such as genetic algorithm, cannot be used to derive a solution in such a highdimensional space. In this paper, we propose an improved genetic algorithm with the local floating searching technique to discover a subset of biomarkers with improved prognostic values for prediction of MACE. The proposed method has been compared with standard genetic algorithm and other feature selection approaches based on the MACE prediction experiments.
