Treatment of skin diseases with the combination of 8-methoxypsoralen and ultraviolet A radiation (PUVA) results in clinical alterations in treated skin that resemble those observed in chronically photodamaged skin. The PUVA-treated patients develop nonmelanoma skin cancers, pigmentary alterations and wrinkling characteristic of sun-induced changes. The major alteration in the dermis of sun-damaged skin is the deposition of abnormal elastic fibers, termed solar elastosis. Up-regulation of elastin promoter activity in dermal fibroblasts explains the excess elastic tissue but not the reason for the aberrant morphology of the elastotic material. In order to study photoaging in an experimental system, we utilized a transgenic mouse line that expresses the human elastin promoter/chloramphenicol acetyltransferase construct in a tissue-specific and developmentally regulated manner. Although UVB radiation has been demonstrated to increase promoter activity in vitro, UVA fails to demonstrate a similar effect at the doses utilized. In this study, we demonstrate the ability of PUVA treatment to up-regulate elastin promoter activity both in vitro and in vivo. These data help to explain the development of photoaging in sun-protected PUVA-treated skin. We attribute the up-regulation of elastin promoter activity in response to PUVA to the formation of DNA photoadducts, which do not occur in response to UVA radiation alone.
FZD4 mutations in either the N- or C-terminal region underlie adFEVR, which indicates that FZD4 plays an important role in retinal angiogenesis. Analysis of FZD4 mutations in families with adFEVR is useful for genetic counseling and for early diagnosis
ABSTRACT.Purpose: To describe the clinical characteristics of a Japanese male patient with enhanced S-cone syndrome (ESCS) and investigate the existence of mutations in the NR2E3 gene, which encodes a photoreceptor cell-specific nuclear receptor. Methods: Fundus examinations, fluorescein angiography, colour vision tests, spectral sensitivity, and full-field and spectral electroretinography were performed. Mutation screening of the NR2E3 gene was performed with polymerase chain reaction (PCR) amplification and direct sequencing. Results: We identified a novel homozygous mutation (c.1048C > T), that converts glutamine (CAA) to a termination codon (TAA) at amino acid position 350. The subject's unaffected parents were heterozygous for the mutation, consistent with autosomal recessive transmission. The electroretinographic findings revealed that the patient had neither rod nor 30-Hz flicker responses but did have cone responses with large a-wave and low b-wave amplitudes, similar to the rod-plus-cone responses, and also substantial short wavelength-sensitive (S) cone and extremely diminished long/middle wavelength-sensitive (L/M) cone responses. In the right eye, spectral sensitivity in the fovea revealed both functional S-cone and remarkably reduced L-and M-cone sensitivities, which was compatible with the decreased visual acuity (VA) and red/green colour vision defects noted in this eye. In contrast, the patient had good VA and normal red/green colour vision in the left eye. Conclusion: The nonsense mutation results in a truncated NR2E3 protein lacking 61 amino acids within the ligand-binding domain (LBD) that consists of 190 amino acids of the C-terminus end. Therefore, null function of the LBD is likely to cause ESCS in the patient. The clinical findings for this patient suggest that his left eye, with its functional L/M-and S-cones, was at an earlier stage of the syndrome than his right eye.
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