Comparison of constitutive gene expression levels of hepatic cholesterol biosynthetic enzymes between Wistar-Kyoto and stroke-prone spontaneously hypertensive rats.

Serum total cholesterol amounts in the stroke-prone hypertensive rat (SHRSP) strain are lower than in the normotensive control strain, Wistar-Kyoto (WKY) rat. To understand the strain difference, constitutive gene expression levels of hepatic cholesterol biosynthetic enzymes in male 8-week-old SHRSP and WKY rats were comparatively examined by DNA microarray and real-time reverse transcription-polymerase chain reaction (RT-PCR) analyses. Of 22 cholesterol biosynthetic enzyme genes, expression levels of 8 genes, Pmvk, Idi1, Fdps, Fdft1, Sqle, Lss, Sc4mol, and Hsd17b7, in SHRSP were less than 50% those of the WKY rats; especially, the expression level of Sqle gene, encoding squalene epoxidase, a rate-limiting enzyme in cholesterol biosynthesis pathway, was about 20%. The gene expression level of sterol regulatory element-binding protein-2 (SREBP-2), which functions as a transcription factor upregulating gene expression of cholesterol biosynthetic enzymes, in SHRSP was about 70% of that in WKY rats. These results demonstrate the possibility that the lower serum total cholesterol level in SHRSP is defined by lower gene expression of most hepatic cholesterol biosynthetic enzymes. In particular, decreased gene expression level of Sqle gene might be the most essential factor. Moreover, the broad range of lowered rates of these genes in SHRSP suggests that the abnormal function and/or expression not only of SREBP-2 but also of one or more other transcription factors for those gene expressions exist in SHRSP.

Super-induced gene expression of the N-methyl-D-aspartate receptor 2C subunit in chemical-induced hypertrophic liver in rats.

To identify gene expression that can be closely involved in chemical-induced hepatocellular hypertrophy, the hepatic gene expression profile was assessed by cDNA microarray analysis in male F344 rats fed for 3 days, 4 weeks, and 13 weeks a diet containing a hepatocellular hypertrophy inducer, either phenobarbital (500 ppm), clofibrate (2,500 ppm), or piperonyl butoxide (20,000 ppm). The results showed that, in all treatment groups, the increased expressional rate of the Grin2c gene, which encodes the N-methyl-D-aspartate receptor 2C subunit (NR2C), was the highest among those of all the genes tested, as compared with the corresponding gene expression in rats fed a normal diet. Moreover, real-time RT-PCR analysis showed that the expression levels of the Grin2c gene in rats fed with each chemical clearly increased in a chemical treatment period-dependent fashion, and that the increased rate was closely correlated with the grade of hypertrophy of hepatocytes rather than with the increased rate in liver weight. These results suggest the possibility that chemical-induced NR2C expression relates to the development of hepatocellular hypertrophy.

Hepatic expression of spermatogenic genes and their transiently remarkable downregulations in Wistar-Kyoto rats in response to lead-nitrate administration: strain-difference in the gene expression patterns.

Administration of lead ion (Pb) to rats and mice affects hepatic functions such as the induction of hepatic cell proliferation and upregulation of cholesterol biosynthesis. To identify the genes for which expression changes in response to Pb-administration, we analyzed hepatic gene expression patterns in stroke-prone spontaneously hypertensive rat (SHRSP), its normotensive control, Wistar-Kyoto rat (WKY), and Spraque-Dawley (SD) rat strains, 3, 6, and 12 hr later after single i.v. injection of lead nitrate (LN) at a dose of 100 µmol using a DNA microarray technique. The data analysis demonstrated that the expression of a great number of genes was transiently and remarkably downregulated 3 hr after LN-injection, and then recovered to control levels only in LN-injected WKY. These normal hepatic expression levels in WKY and SHRSP were much higher than those in SD rats. Furthermore, most of these genes were ones thought to be expressed specifically in the spermatids and/or testes; i.e. genes encoding protamin 1, transition protein 1, and transition protein 2. These findings suggest that the regulation system common to expression of all of these genes could be a target site of Pb-toxic action, at least, in the liver of WKY, and that this system might be similar to the system essential for spermatogenesis, especially spermiogenesis, in the testis. In addition, it appears that clarifying the cause of the difference between the systems of WKY and SHRSP might aid in identifying the pathologic genes in SHRSP. Finally, it will be an important to clarify how the products of the genes related to spermatogenesis, including spermiogenesis, are functional in the livers of WKY and SHRSP.

[A case of cystic maculopathy during paclitaxel therapy].

BACKGROUND: Paclitaxel, one of the taxanes, has been used to treat malignant tumors such as breast cancer. It is known to cause cystic maculopathy as an unusual ocular side effect. Here, we describe the clinical features of a patient who suffered cystic maculopathy during paclitaxel therapy. CASE: A 62-year-old woman complained of visual disturbances in both eyes after receiving paclitaxel treatment of six months for metastatic breast cancer. Because cystic maculopathy was discovered during observation, and the paclitaxel therapy was discontinued. After about six weeks of acetazolamide administration, the cystic maculopathy disappeared and visual acuity had recovered. CONCLUSION: Paclitaxel treated patients should be followed carefully for ophthalmic complications, especially cystic maculopathy.

[Three cases of corneal disorders associated with an oral anticancer drug S-1].

PURPOSE: S-1 is a new oral anticancer drug containing tegafur, which is a prodrug of 5-fluorouracil. In this report, we describe the clinical features of three patients who suffered corneal disorders that seemed to be caused by S-1 administration. CASES: One female and two male patients, whose ages ranged from 57 to 69 years, were entered in this study. Between 3 to 14 months after they started oral S-1 therapy, they experienced sudden visual reduction. They all had corneal disorders, which occurred in the inferior and the superior areas, and progressed toward the center. As the corneal disorders invaded the pupil area, the patients noticed visual disturbance. They recovered their vision and their corneal disorders diminished when the drug was discontinued. However, after the drug intake was resumed, the corneal disorders occurred again in some cases. All patients also had lacrimal obstructions. CONCLUSION: S-1 treated patients should be followed carefully for ophthalmic complications because corneal disorders are likely to appear.

Novel mutations in the arrestin gene and associated clinical features in Japanese patients with Oguchi's disease.

PURPOSE: Only 2 mutations in the arrestin gene have been previously reported to be associated with Oguchi's disease, a homozygous Asn309(1-bp del) mutation in Japanese families and a homozygous Arg193stop mutation in an Indian family. The aim of this article is to report 2 novel mutations in the arrestin gene in 2 Japanese patients with Oguchi's disease and to describe the clinical features with the mutations. DESIGN: Molecular genetic study and observational case report. PARTICIPANTS: Two unrelated Japanese patients with Oguchi's disease associated with novel arrestin mutations. METHODS: Genomic DNA was extracted from leukocytes of the peripheral blood, and exons 2 through 16 of the arrestin gene were amplified by polymerase chain reaction and directly sequenced. A complete ophthalmologic examination was performed, including best-corrected visual acuity, slit-lamp and fundus examinations, fundus photography, and electroretinography (ERG). MAIN OUTCOME MEASURES: Direct sequencing of the arrestin gene, evaluation of visual acuity, refraction, and ERG. RESULTS: Three arrestin gene mutations were identified in 2 patients. A compound heterozygous mutation, Arg175stop and Asn309(1-bp del), was identified in 1 patient with Oguchi's disease. The former mutation has not been reported, whereas the latter is known to be a frequent mutation in Oguchi's disease in Japanese families. In a second patient, another novel mutation was detected in the gene, a homozygous Arg292stop mutation. Both patients demonstrated characteristic features of Oguchi's disease, including night blindness, golden-yellow discoloration of the retina, absent rod ERG response, and "negative" type bright-flash ERG after 30 minutes of dark adaptation. CONCLUSIONS: The existence of 2 novel mutations of the arrestin gene in 2 unrelated Japanese patients strongly supports the previous data that arrestin gene mutations are associated with Oguchi's disease. All of the mutations in the arrestin gene that have been identified in Oguchi's disease are null mutations, indicating that only critical gene defects in the arrestin gene are associated with Oguchi's disease.

Autosomal dominant cone-rod dystrophy with R838H and R838C mutations in the GUCY2D gene in Japanese patients.

PURPOSE: To describe the clinical phenotypes of two Japanese families with autosomal dominant cone-rod dystrophy (CORD) caused by an R838H or R838C mutation. METHODS: Complete ophthalmological examinations were performed on three affected individuals from two Japanese families with autosomal dominant CORD. One family had an R838H mutation, and the other family had an R838C mutation in the GUCY2D gene. The tests included best-corrected visual acuity, slit-lamp and fundus examinations, fundus photography, electroretinography, Goldmann kinetic perimetry, and automated light- and dark-adapted static perimetry. RESULTS: The three patients showed essentially normal fundus or little pigmentary change in the maculae by indirect ophthalmoscopy, and only fluorescein angiography revealed clear atrophy of the retinal pigmented epithelium around the fovea. Central or paracentral scotoma was detected by the Goldmann kinetic visual field test. Electroretinography as well as light-adapted and dark-adapted two-color perimetry showed more severe impairment of cone than of rod function. The clinical features in our patients resembled those in Caucasian families with R838H or R838C mutations. CONCLUSIONS: The R838H and R838C mutations in GUCY2D cause CORD in the Japanese population. These mutations can cause a similar clinical phenotype in other races.

Novel complex GUCY2D mutation in Japanese family with cone-rod dystrophy.

PURPOSE: All mutations in the retinal guanylate cyclase gene (GUCY2D) that causes autosomal dominant cone-rod dystrophy (CORD) are associated with an amino acid substitution in codon 838. A novel heterozygous complex missense mutation of I915T and G917R in the GUCY2D gene was found in a Japanese family with autosomal dominant CORD. The clinical features associated with this mutation were described. METHODS: Blood samples were collected from 27 patients with cone-rod or cone dystrophies and from 11 patients with macular dystrophy. Genomic DNA was extracted from peripheral leukocytes. All 18 coding exons of the GUCY2D gene were directly sequenced. The PCR product carrying a novel mutation was subcloned, and each allele was sequenced. A complete ophthalmologic examination was performed in members of the family with the novel mutation. RESULTS: A novel heterozygous complex missense mutation of T2817C and G2822C that would predict I915T and G917R amino acid substitutions, respectively, was found in an autosomal dominant CORD family. The two nucleotide changes were located on the same allele, and segregated with the disease. Two other known missense mutations of R838H and R838C were found in two other CORD families. The clinical phenotype associated with the novel mutation was similar to that with the Arg838 mutations. CONCLUSIONS: A heterozygous complex mutation of I915T and G917R in the GUCY2D gene caused autosomal dominant CORD, indicating that a heterozygous mutation that does not include a codon 838 substitution can lead to this ocular phenotype.

Retinal and optic disc atrophy associated with a CACNA1F mutation in a Japanese family.

OBJECTIVE: To describe retinal and optic disc atrophy and a progressive decrease of visual function in 2 Japanese brothers. Both had a mutation in the CACNA1F gene, the causative gene of incomplete congenital stationary night blindness (CSNB). METHODS: We studied observational case reports and performed comprehensive ophthalmologic examinations including best-corrected visual acuity, biomicroscopy, ophthalmoscopy, fundus photography, and electroretinography. Genomic DNA was extracted from the peripheral blood, and all 48 exons of the CACNA1F gene were directly sequenced. RESULTS: The 2 brothers had retinal and optic disc atrophy and a progressive reduction of visual acuity with increasing age. Although these clinical features are not typical of previous patients with incomplete CSNB, both patients had an in-frame mutation with deletion and insertion in exon 4 of the CACNA1F gene. In both patients, the bright-flash, mixed rod-cone electroretinogram had a negative configuration, a characteristic of incomplete CSNB. However, the full-field scotopic and photopic electroretinograms were nonrecordable, indicating severe, diffuse retinal malfunction, which is not typical in incomplete CSNB. CONCLUSION: These findings indicate that a mutation of the CACNA1F gene may be associated with retinal and optic disc atrophy with a progressive decline of visual function. Clinical Relevance In patients with retinal and optic disc atrophy associated with negative-type electroretinograms, a CACNA1F gene mutation should be considered.

Macular dystrophy in a Japanese family with fundus albipunctatus.

PURPOSE: To report a Japanese family with fundus albipunctatus and macular dystrophy associated with a mutation in the 11-cis retinol dehydrogenase (RDH5) gene. DESIGN: Observational case report. METHOD: Ophthalmic examinations and DNA analysis were performed. RESULTS: The fundi of a 56-year-old man and his 51-year-old sister showed numerous yellow-white punctata. He also had bull's-eye maculopathy and prepappillary arterial loops, whereas she did not, and his best-corrected visual acuity was impaired, whereas hers was normal. Their kinetic visual fields did, however, show central or paracentral scotoma, and both had tritanomalous color vision. Their scotopic electroretinograms were typical of fundus albipunctatus, and photopic electroretinograms were significantly reduced. A homozygous Gly107Arg mutation in the RDH5 gene was detected in both siblings. CONCLUSIONS: We suggest that the macular dystrophy is caused by the RDH5 gene mutation as a phenotype variation in fundus albipunctatus.

Incomplete congenital stationary night blindness associated with symmetrical retinal atrophy.

PURPOSE: To describe a Japanese patient with incomplete congenital stationary night blindness (iCSNB) with atypical retinal atrophy and kinetic visual field defects. METHODS: An ophthalmologic examination was performed, and the CACNA1F gene was analyzed by direct genomic sequencing. RESULTS: The patient had a hemizygous Arg913stop mutation in CACNA1F and had electroretinographic changes that were typical of iCSNB. The fundus had atrophic retinal lesions around the inferior vascular arcades OU, and Goldmann kinetic perimetry showed relative scotomas in the corresponding areas. CONCLUSIONS: Although most patients with iCSNB show essentially normal fundi without visual field defects, this case demonstrated retinal atrophy associated with visual field defects indicating a phenotypic heterogeneity induced by the CACNA1F mutation.

Novel de novo mutation in CRX gene in a Japanese patient with leber congenital amaurosis.

PURPOSE: To report a novel de novo mutation in the cone-rod homeobox (CRX) gene in a Japanese patient with Leber congenital amaurosis (LCA). METHODS: The CRX gene was analyzed by direct genomic sequencing in a patient with LCA and in his healthy parents. A complete ophthalmologic examination was performed on the family. RESULTS: A heterozygotic deletion of G at nucleotid 520 in CRX, predicting a frameshift in codon 174 and a premature termination of translation [Ala174(1-bp del)], was identified in the proband. The mutation was not present in his unaffected parents. CONCLUSION: A novel de novo mutation in CRX was found in a Japanese patient with LCA.