The epigenetic modification of mitochondrial DNA (mtDNA) is still in controversy. To clarify this point, we applied the gold standard method for DNA methylation, bisulfite pyrosequencing, to examine human mtDNA methylation status. Before bisulfite conversion, BamHI was used to digest DNA to open the loop of mtDNA. The results demonstrated that the linear mtDNA had significantly higher bisulfite conversion efficiency compared with circular mtDNA. Furthermore, the methylation values obtained from linear mtDNA were significantly lower than that of circular mtDNA, which was verified by SEQUENOM MassARRAY. The above impacts of circular structure were also observed in lung DNA samples but not in saliva DNA samples. Mitochondrial genome methylation of blood samples and saliva samples from 14 unrelated individuals was detected. The detected regions covered 83 CpG sites across mtDNA including D-loop, 12 S rRNA, 16 S rRNA, ND1, COXI, ND3, ND4, ND5, CYTB. We found that the average methylation levels of nine regions were all less than 2% for both sample types. In conclusion, our findings firstly show that the circular structure of mtDNA affects bisulfite conversion efficiency, which leads to overestimation of mtDNA methylation values. CpG methylation in human mtDNA is a very rare event at most DNA regions.

FT-Raman spectra were obtained for thiophenol UP) and TP on gold nanoparticles. All vibrational fundamentals for the TP molecule are assigned on the basis of the scaled quantum force field procedure. Three model systems are studied and compared for the interactions of TP with the Au atom: (1) TP with a Au atom, C6H5SH-Au; (2) TP anion with a Au atom, C6H5S--Au; and (3) TP with a Au atom and subsequent formation of thiophenylate, C6H5SAu. The equilibrium structures and Raman spectra were calculated for the model systems using density functional theory (DFT) with the B3LYP functionals and the mixed basis set 6-311+G** (for C, S, H) and LANL2DZ (for Au), and theoretical Raman wavenumbers of C6H5SAu and C6H5S--Au were assigned according to potential energy distributions. The third model system is shown to be preferred over the other two. The calculated binding energies are also shown to support the third model system. It is suggested that a simple model, such as the one used in the present study, is reasonable to describe surface-enhanced Raman spectroscopy of thiophenol adsorbed on gold nanoparticles. Copyright (C) 2007 John Wiley & Sons, Ltd

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We identified three heterozygous mutations in CTNNA1 in familial exudative vitreoretinopathy (FEVR) patients, and these mutations resulted in overactivation of Norrin/βcatenin signaling and disruption of the cadherin/catenin complex. • Clinical features of FEVR were reproduced in mice lacking Ctnna1 in vascular endothelial cells and in mice with an endothelial-cell-specific gain-of-function Ctnnb1 allele. • In a large Indian family with FEVR, we identified an LRP5 mutation (p.P848L) that results in overactivation of Norrin/β-catenin signaling, and we observed clinical features of FEVR in the retina of Lrp5 P847L knock-in mice. • The precise regulation of β-catenin activation is critical for normal retinal vascular development. What Are the Clinical Implications? • Because both in-and overactivation of Norrin/β-catenin signaling can cause defective angiogenesis, careful monitoring during drug treatment targeting β-catenin is warranted. • The cadherin/catenin complex has the potential to be a therapeutic target for other neovascular diseases affecting the blood-brain barrier, which contribute to altered brain function and intellectual disability.

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