Traditional Japanese herbal (kampo) medicines and treatment of ocular diseases: a review.

Herbal medicines have been used clinically in Eastern Asia, and traditional Japanese herbal (Kampo) formulas are approved as ethical drugs. The Kampo formulas are mixtures of the crude extracts of several herbs, each of which contains multiple components. Numerous investigators have reported that some herbal medicines are efficacious for treating several human diseases. We reviewed the literature on traditional herbal medicines and treatment of ocular diseases. Oral Orengedoku-to and Kakkon-to inhibit postoperative uveitis in humans. Oral Goshajinki-gan improved ocular surface disorders in patients with type 1 diabetes mellitus. Oral Hachimijio-gan increased retinal blood flow. Keishi-bukuryo-gan Sho might be associated with vitreoretinopathy in patients with type 2 diabetes mellitus. Oral Hachimijio-gan and Goshajinki-gan delayed lens opacification in rats and mice. Oral Sairei-to, Orengedoku-to, Senkanmeimoku-to, Scutellariae radix extract, Gardeniae fructus extract, topical Liguisticum wallichii rhizoma extract, and intravenous injection of tetramethylpyrazine, baicalin, baicalein, wogonin, and crocetin inhibited some forms of experimental uveitis in rabbits. Topical glycyrrhizinate improved allergic conjunctivitis in humans and rats. Oral crocetin improved eyestrain in humans. Oral berberine diminished experimental uveitis in rats. Baicalein, wogonin, berberine, and berberrubine inhibited in vitro expression of several cytokines in cultured retinal pigment epithelial cells. Some Kampo formulas are efficacious for treating several ocular diseases in humans and animals. Some herbal extracts and their components inhibit some forms of experimental uveitis.

Retinal risks of high-dose ornithine supplements: a review.

We reviewed the literature on ornithine supplementation and related topics. Nutritionists and physicians have reported that ornithine supplementation is useful. Paediatricians and biochemists have reported that ornithine is supplemented for NH(3) detoxification in the hyperornithinaemia-hyperammonaemia-homocitrullinuria (HHH) syndrome. In contrast, ophthalmic researchers have reported retinotoxicity associated with high-dose ornithine. In vivo and in vitro experiments have shown that high concentrations of ornithine or its metabolites are toxic to the retinal pigment epithelial (RPE) cells. Long-term (exceeding a few years) and high concentrations (exceeding 600 µmol/l) of ornithine in the blood induce retinal toxicity in gyrate atrophy of the choroid and retina (GA). Intermittent high levels of ornithine do not lead to retinal lesions. Constant blood ornithine levels between 250 and 600 µmol/l do not induce retinal lesions or cause a very slowly progressive retinal degeneration. Blood ornithine levels below 250 µmol/l do not produce retinal alteration. We concluded that short-term, low-dose or transient high-dose ornithine intake is safe for the retina; its nutritional usefulness and effect on NH(3) detoxification are supported by many researchers, but the effect may be limited; and long-term, high-dose ornithine intake may be risky for the retina. Patients with GA should avoid taking ornithine; amino acid supplementation should be administered carefully for patients with the HHH syndrome, relatives of patients with GA (heterozygotes) and subjects with RPE lesions; and blood ornithine levels and retinal conditions should be evaluated in individuals taking long-term, high-dose ornithine.

A cholinergic agonist attenuates endotoxin-induced uveitis in rats.

PURPOSE: Investigation of physiological anti-inflammatory mechanisms can contribute to the treatment of inflammatory disorders. The purpose of the present study was to investigate the effect of nicotine, a selective cholinergic agonist, on endotoxin-induced uveitis (EIU) in rats and the underlying molecular mechanism. METHODS: Lipopolysaccharide (LPS; endotoxin) and nicotine were injected intraperitoneally. Clinical scores were evaluated by slit lamp. Intracameral protein content and the number of cells were determined. Immunohistochemical reactivity of alpha7 nicotine acetylcholine receptor (alpha7nAChR) was examined in the iris and ciliary body (ICB). mRNA and protein levels of cytokines and chemokines were measured by real-time PCR and enzyme-linked immunosorbent assay. RESULTS: After LPS injection, clinical scores, as well as protein content and number of cells in the aqueous humor increased during 18 to 36 hours. Nicotine inhibited the endotoxin-induced elevation of these levels. mRNA and protein of alpha7nAChR expression levels were significantly increased by LPS and/or nicotine injection. Nicotine showed no effects on endotoxin-induced elevation of mRNA levels in ICB. However, nicotine decreased the endotoxin-induced elevation of interleukin (IL)-6, IL-1beta, tumor necrosis factor (TNF)-alpha, cytokine-induced neutrophil chemoattractant (CINC)-1, and monocyte chemotactic protein (MCP)-1, but did not affect IL-10 in the serum and aqueous humor. CONCLUSIONS: Nicotine attenuated endotoxin-induced uveitis through directly decreasing the levels of multiple cytokines and chemokines in the aqueous humor, but did not affect the mRNA levels of these factors. The findings suggest that the nicotinic anti-inflammatory pathway may be involved in the pathogenesis of EIU.

Effect of N-acetylcysteine on lipopolysaccharide-induced uveitis in rats.

PURPOSE: In this study we investigated the in vivo effect of N-acetylcysteine (NAC) on lipopolysaccharide (LPS)-induced uveitis in rats. METHODS: To induce uveitis, LPS (100 microg) was injected into subcutaneous tissue of Wistar rats (170-190 g). NAC was injected intraperitoneally. Intracameral levels of protein, cells, nitrite, tumor necrosis factor (TNF)-alpha, and interleukin (IL)-6 were determined by spectrophotometry, hemocytometry, and enzyme-linked immunosorbent assay. Expression of TNF-alpha, IL-6, endothelial leukocyte adhesion molecule-1 (E-selectin), intercellular adhesion molecule-1 (ICAM-1), and inducible nitric oxide synthase (iNOS) mRNA was examined by real-time polymerase chain reaction. RESULTS: LPS injection elevated intracameral protein and cells, and the elevation was inhibited by NAC. LPS injection induced expression of TNF-alpha, IL-6, E-selectin, and ICAM-1 mRNA in the iris/ciliary body at 3 h, and iNOS mRNA at 6 h. The LPS-induced elevation of the mRNA levels was inhibited by NAC. NAC inhibited LPS-induced intracameral elevation of TNF-alpha, IL-6, and nitrite. CONCLUSION: NAC decreased LPS-induced uveitis in vivo by reducing the expression of proinflammatory cytokines and adhesion molecules.

Effect of berberine on barrier function in a human retinal pigment epithelial cell line.

PURPOSE: To examine the effects of berberine, an alkaloid isolated from some medicinal herbs, on the disruption of the barrier function in a human retinal pigment epithelial cell line (ARPE-19) stimulated with interleukin-1beta (IL-1beta). METHODS: ARPE-19 cells were cultured to confluence. Berberine and IL-1beta were added to the medium. Barrier functions were evaluated by measuring transepithelial electrical resistance (TER) and the permeability to horseradish peroxidase (HRP) and sodium fluorescein (SF). RESULTS: Berberine dose-dependently inhibited decreased TER and increased the permeability to HRP and SF in the cells stimulated with IL-1beta. CONCLUSIONS: Berberine dose-dependently inhibited the disruption of the barrier function in the ARPE-19 cell line induced by IL-1beta.

S100A9-positive granulocytes and monocytes in lipopolysaccharide-induced anterior ocular inflammation.

S100A9 is a pro-inflammatory protein expressed in infiltrating granulocytes and monocytes. We determined role of S100A9 in endotoxin (LPS)-induced uveitis (EIU) and keratitis in Wistar rats. Anti-S100A9 antibody decreased partially clinical scores, protein, and cells in the aqueous humor at 18-36 h, compared with the LPS group. S100A9-positive cells were expressed in the iris-ciliary body (ICB) and cornea at 24-48 h. Activated caspase-3 (related to apoptosis) and S100A9 co-expressed in ICB at 18-48 h after LPS injection. S100A9 was not expressed in ED2-positive cells in ICB. Dexamethasone (DEX) increased S100A9 mRNA and protein levels in the circulating blood leukocytes, but reduced S100A9 mRNA and protein levels in ICB after LPS injection. BAY 11-7085 (an inhibitor of I-kappaB phosphorylation) suppressed S100A9 mRNA in leukocytes (43.5%) and ICB (68.5%), respectively, after LPS injection. It is possible that S100A9-positive granulocytes and monocyte/macrophages may play a role in the late phase of EIU and keratitis that DEX may inhibit the migration of S100A9-positive granulocytes and monocytes from the blood into the extravascular tissues, and that nuclear factor (NF)-kappaB pathway may be involved in S100A9 expression. S100A9 could play a role in the clearance of inflammatory cells at the late phase of EIU.

Effect of berberine on monocyte chemotactic protein-1 and cytokine-induced neutrophil chemoattractant-1 expression in rat lipopolysaccharide-induced uveitis.

PURPOSE: The aims of this study were to examine the in vivo effects of berberine, an alkaloid isolated from some medicinal herbs, on monocyte chemotactic protein-1 (MCP-1) and cytokine-induced neutrophil chemoattractant-1 (CINC-1) expression in rat lipopolysaccharide (LPS)-induced uveitis. METHODS: LPS was injected intraperitoneally. Berberine was orally administered. MCP-1 mRNA and CINC-1 mRNA were measured by semiquantitative reverse-transcription polymerase chain reaction and real-time polymerase chain reaction. MCP-1 and CINC-1 protein concentration in the aqueous humor were measured by enzyme-linked immunosorbent assay. Histopathologic study was performed in the anterior ocular segments. RESULTS: Berberine dose-dependently inhibited LPS-induced MCP-1 mRNA and CINC-1 mRNA expression of the iris-ciliary body. The alkaloid inhibited chemokines, protein and cell levels in the aqueous humor in rats stimulated with LPS. On histopathologic study, the inflammatory cell infiltration was diminished by the berberine treatment. CONCLUSIONS: These findings indicate that berberine dose-dependently inhibited the expression of MCP-1 and CINC-1 induced by LPS and diminished the anterior uveitis.

Vitreous Chemokines and Sho (Zheng in Chinese) of Chinese-Korean-Japanese medicine in patients with diabetic vitreoretinopathy.

We examined the levels of vitreous chemokines and Sho (Zheng in Chinese) of Chinese-Korean-Japanese medicine in diabetic patients. Patients undergoing vitrectomy were classified into Group 1 (no diabetic retinopathy), Group 2 (diabetic retinopathy with no or a few new vessels), and Group 3 (diabetic retinopathy with many new vessels). The levels of IL-8, MCP-1, MIP-1alpha, MIP-1beta, and RANTES in the vitreous fluid were measured using cytometric bead array method. Sho was determined by the standard diagnostic method of Chinese-Korean-Japanese medicine. Vitreous levels of IL-8 and MCP-1 in Groups 2 and 3 were higher than those in Group 1. MIP-1alpha, MIP-1beta, and RANTES levels in Groups 2 and 3 were almost the same as those in Group 1. The percentage of patients with Keishibukuryo-gan (Guizhifuling-wan in Chinese) sho in Group 3 was higher than that in Group 1. In conclusion, vitreous levels of IL-8 and MCP-1 were high in patients with diabetic vitreoretinopathy. Keishibukuryo-gan sho may be associated with diabetic vitreoretinopathy.

Effect of berberrubine on interleukin-8 and monocyte chemotactic protein-1 expression in human retinal pigment epithelial cell line.

We examined the effects of berberrubine, a protoberberine alkaloid, on interleukin-8 (IL-8) and monocyte chemotactic protein-1 (MCP-1) expression in a human retinal pigment epithelial cell line (ARPE-19) stimulated with interleukin-1beta (IL-1beta) or tumor necrosis factor alpha (TNF-alpha). ARPE-19 cells were cultured to confluence. Berberrubine and IL-1beta or TNF-alpha were added to the medium. IL-8 and MCP-1 protein concentrations were measured using enzyme-linked immunosorbent assay. IL-8 and MCP-1 mRNA were measured by real time polymerase chain reaction. Nuclear factor kappaB (NF-kappaB) translocation was examined by immunofluorescent staining/microscopy. Berberrubine dose-dependently inhibited IL-8 and MCP-1 protein levels in the media and mRNA expression of the cells stimulated with IL-1beta or TNF-alpha. Immunofluorescent staining/microscopy of NF-kappaB in the nucleus of unstimulated cells was faint (51+/-14 arbitrary units). Fluorescein was dense (215+/-42 or 170+/-24 arbitrary units, respectively) 30 min after stimulation with IL-1beta or TNF-alpha and was decreased to 62+/-18 or 47+/-16 arbitrary units, respectively, by berberrubine. Berberrubine dose-dependently inhibited IL-8 and MCP-1 expression and protein secretion induced by IL-1beta or TNF-alpha. Possibly, the effect on chemotactic factors may be via suppression of NF-kappaB translocation.

Alkali burns of the eye: effect of immediate copious irrigation with tap water on their severity.

PURPOSE: To examine the effect of immediate irrigation on ocular alkali burn. METHODS: Information on the injury, immediate irrigation, and ocular findings was retrospectively obtained from each patient's record. RESULTS: 36 patients (49 eyes) irrigated their eyes with tap water (the irrigation group) and 17 patients (29 eyes) did not (no irrigation group). The mean age of patients in the irrigation and no irrigation groups was 30 and 53 years, respectively. According to Hugher's classification, 76% of eyes in the irrigation group had grade 1 injury, while 86% of eyes in the no irrigation group had grade 2 injuries. Mean time from the injury until healing was 8 days in the irrigation group and 29 days in the no irrigation group, respectively. CONCLUSION: Immediate copious irrigation with tap water reduced the severity in alkali burns of the eye and shortened the healing time.

Ocular findings in Japanese children with nephrotic syndrome receiving prolonged corticosteroid therapy.

OBJECTIVE: To examine ocular findings in Japanese children with nephrotic syndrome who receive prolonged corticosteroid treatment. METHODS: Information was retrospectively obtained from each patient's record. RESULTS: A total of 45 children (30 boys and 15 girls) were enrolled. Twenty-one patients (46.7%) had epiblepharon with inverted eyelashes. The incidence of epiblepharon was associated with overweight and obesity. Fifteen patients (33.3%) developed posterior subcapsular cataract in both eyes. Of the 15 patients, 4 had visual acuity less than 0.4 and underwent cataract extraction in both eyes. Nine patients (20%) developed intraocular pressure higher than 22 mm Hg during corticosteroid treatment. The total dose and duration of corticosteroid treatment were associated with cataract formation but were unassociated with elevated intraocular pressure. One boy had elevated intraocular pressure after cessation of corticosteroid therapy and underwent trabeculectomy. One patient had repeated hordeolum in the left eyelid. Three patients had bilateral bacterial conjunctivitis. CONCLUSION: Children with nephrotic syndrome who receive corticosteroid treatment may have epiblepharon, cataract, ocular hypertension, hordeolum and bacterial conjunctivitis.

Effect of berberine on interleukin 8 and monocyte chemotactic protein 1 expression in a human retinal pigment epithelial cell line.

PURPOSE: The aims of this study were to examine the effects of berberine, an alkaloid isolated from some medicinal herbs, on interleukin 8 (IL-8) and monocyte chemotactic protein 1 (MCP-1) expression in a human retinal pigment epithelial cell line (ARPE-19) stimulated with interleukin 1beta (IL-1beta) or tumor necrosis factor alpha (TNF-alpha). METHODS: ARPE-19 cells were cultured to confluence. Berberine and IL-1beta or TNF-alpha were added to the medium. IL-8 mRNA and MCP-1 mRNA were measured by semiquantitative reverse-transcription polymerase chain reaction and real-time polymerase chain reaction. IL-8 and MCP-1 protein concentrations in the media were measured using enzyme-linked immunosorbent assay. RESULTS: Berberine dose-dependently inhibited IL-8 mRNA and MCP-1 mRNA expression of the cells and protein levels in the media stimulated with IL-1beta or TNF-alpha. CONCLUSION: These findings indicate that berberine dose-dependently inhibited the expression of IL-8 and MCP-1 induced by IL-1beta or TNF-alpha.

Functional health status of patients at initial visit in primary eye clinic assessed using the Japanese versions of the COOP charts.

Patient health status was evaluated using Japanese versions of COOP charts. The subconjunctival hemorrhage group scored 3.6 in overall health and 3.7 in change in health. The painful outer eye disease group scored higher than 3.0 in feeling, pain, change in health, and quality of life. The seeing floaters group scored higher than 3.0 in feeling, overall health, change in health, and quality of life.

Effect of pituitary adenylate cyclase-activating polypeptide (PACAP) on IL-6, IL-8, and MCP-1 expression in human retinal pigment epithelial cell line.

PURPOSE: To examine pituitary adenylate cyclase-activating polypeptide (PACAP) receptors (PAC1, VPAC1, and VPAC2) mRNA and the effect of PACAP on interleukin-6 (IL-6), interleukin-8 (IL-8), and monocyte chemotactic protein-1 (MCP-1) expression in human retinal pigment epithelial cell line (ARPE-19) stimulated with interleukin-1beta (IL-1beta). METHODS: Expression of PACAP receptor mRNA was examined by reverse transcription polymerase chain reaction (RT-PCR). PACAP and IL-1beta were added to serum-free medium. IL-6, IL-8, and MCP-1 mRNA were measured by real-time PCR. IL-6, IL-8, and MCP-1 protein concentrations were measured using enzyme-linked immunosorbent assay. Nuclear factor kappaB (NF-kappaB) translocation was examined by immunofluorescence. RESULTS: PAC1 and VCAP1 receptors mRNA were expressed in unstimulated cells. VCAP2 mRNA was expressed in cells stimulated with IL-1beta. IL-1beta stimulated IL-6, IL-8, and MCP-1 mRNA expression and protein levels. PACAP (10(- 7) to 10(- 6) M) inhibited IL-1beta -stimulated IL-6, IL-8, and MCP-1 mRNA and protein levels. Immunofluorescence of NF-kappaB in the nucleus was dense 30 min after stimulation with IL-1beta, and it was decreased by PACAP. CONCLUSIONS: ARPE-19 cells had PACAP receptors mRNA. PACAP inhibited IL-6, IL-8, and MCP-1 expression and protein secretion. Possibly, the effect on cytokines may be via suppression of NF-kappaB translocation.

Epiblepharon with inverted eyelashes and high body mass index in Japanese children.

PURPOSE: To evaluate the sexual predilection of epiblepharon in Japanese children and the relationship between this condition and body mass index. SUBJECTS AND METHODS: Japanese children who were 6 to 14 years old were cross-sectionally surveyed on routine health screening. RESULTS: Of 2,941 children examined, 127 had epiblepharon. The incidence decreased with age. No sexual predilection was found. Lower eyelids were commonly involved bilaterally. Mild complaints included discomfort or foreign body sensation. The body mass index in children 6 to 11 years old with epiblepharon was higher than that in children without epiblepharon. CONCLUSIONS: No sexual predilection was found for epiblepharon. A high body mass index was noted in children with epiblepharon who were 6 to 11 years old.

Peripherin/RDS gene in Indonesian patients with retinitis pigmentosa: geographic comparison of polymorphic variations.

To analyze peripherin/RDS (retinal degeneration slow) gene alterations in Indonesian patients with retinitis pigmentosa. We examined the gene in 13 unrelated Indonesian patients with retinitis pigmentosa and in 24 normal individuals. Peripheral venous blood was extracted, and genomic DNAs were amplified by polymerase chain reaction (PCR). The PCR products were directly sequenced. Each subject underwent ocular examination. The prevalence of the gene alteration was compared to that reported in Japanese and Caucasian populations. Among 13 patients, 3 concurrently had Glu304Gln and Gly338 Asp alterations at exon 3 of the peripherin/RDS gene. Two patients had heterozygous alterations and one had a homozygous variation. The prevalence of the alterations (23%) in Indonesian patients was similar to that in Japanese patients (26%) and was lower than that in Caucasian patients (30-70%). The alterations were also observed in 7 of 24 (29%) normal healthy Indonesian individuals. Peripherin/RDS gene polymorphisms (Glu304Gln and Gly338Asp) were found in Indonesian patients with retinitis pigmentosa. The prevalence of alterations in Indonesian patients was similar to that in Japanese patients and lower than in Caucasian patients.

Effect of alpha-melanocyte-stimulating hormone on interleukin 8 and monocyte chemotactic protein 1 expression in a human retinal pigment epithelial cell line.

PURPOSE: To examine melanocortin receptor (from MC-1 to MC-5) mRNA and the effect of alpha-melanocyte-stimulating hormone (alpha-MSH) on interleukin 8 (IL-8) and monocyte chemotactic protein 1 (MCP-1) expression in a human retinal pigment epithelial cell line (ARPE-19) stimulated with IL-1beta or tumor necrosis factor alpha (TNF-alpha). METHODS: Expressions of MC-1 to MC-5 mRNA were examined by semiquantitative reverse transcription polymerase chain reaction (RT-PCR). alpha-MSH and IL-1beta or TNF-alpha were added to serum-free medium. IL-8 and MCP-1 mRNA were measured by real-time PCR. IL-8 and MCP-1 protein concentrations were measured using enzyme-linked immunosorbent assay. Nuclear factor kappaB (NF-kappaB) translocation was examined by immunofluorescent staining/microscopy. RESULTS: MC-1 to MC-5 receptor mRNA was expressed in unstimulated cells. IL-1beta stimulated IL-8 and MCP-1 mRNA at 6 h. TNF-alpha stimulated IL-8 and MCP-1 mRNA expression at 1.5 and 3 h. alpha-MSH (10(-14) to 10(-10)M) inhibited IL-8 and MCP-1 mRNA expression in the cells stimulated with IL-1beta or TNF-alpha. alpha-MSH inhibited IL-1beta or TNF-alpha-stimulated IL-8 and MCP-1 protein levels in the media. Immunofluorescent staining/microscopy of NF-kappaB in the nucleus was dense 30 min after stimulation with IL-1beta or TNF-alpha and was decreased by alpha-MSH. CONCLUSIONS: ARPE-19 cells had MC-1 mRNA. alpha-MSH inhibited IL-8 and MCP-1 expression and protein secretion. Possibly, the effect on chemotactic factors may be via suppression of NF-kappaB translocation.

Uveitis and pseudouveitis presenting for the first time in Japanese elderly patients.

PURPOSE: To evaluate the clinical characteristics of uveitis or pseudouveitis presenting de novo in Japanese elderly patients. METHODS: We retrospectively examined 296 patients with uveitis or pseudouveitis who were treated at Toyama Medical and Pharmaceutical University Hospital. Patients were followed up for 1 week to 5 years (mean, 11 months). RESULTS: Of 296 patients, 82 (38 men and 44 women, 120 eyes) presented with their first episode of uveitis or pseudouveitis at the age of > or = 60 years. Forty patients had anterior uveitis, 2 had intermediate uveitis and the other 40 had posterior and/or pan-uveitis. Of 82 patients, 53 (64.6%) had idiopathic uveitis. The prevalence of Vogt-Koyanagi-Harada syndrome and Behçet disease in elderly patients was lower than that in younger patients. Complicated cataract was frequently seen in the eyes with uveitis. Most eyes with uveitis had poor visual acuity. CONCLUSIONS: The prevalence of Vogt-Koyanagi-Harada syndrome and Behçet disease in elderly patients was lower than that in younger patients.

Ocular findings in Japanese patients with varicella-zoster virus infection.

PURPOSE: To examine ocular findings in Japanese patients with varicella, herpes zoster ophthalmicus, and acute retinal necrosis. METHODS: A retrospective study was conducted. Information on the ocular, cutaneous, systemic, and virologic findings on pediatric and adult patients was obtained from medical records. RESULTS: A total of 77 (45 male and 32 female) patients were enrolled in the study: 4 children had varicella, 68 adults had herpes zoster ophthalmicus, and 5 adults had acute retinal necrosis. Children with varicella had eruptions on the eyelid. Patients with herpes zoster ophthalmicus had eruptions, conjunctivitis, keratitis, iridocyclitis, and other findings. Patients with acute retinal necrosis had intracameral cells and retinal lesions. Some patients with herpes zoster ophthalmicus had malignancy, type 2 diabetes mellitus, or other disease. One pregnant woman developed acute retinal necrosis shortly after varicella infection. A total of 48% of patients with negative Hutchinson sign had ocular lesions, while all patients with positive sign showed ocular lesions. Patients with varicella and herpes zoster ophthalmicus had good visual acuity at the last visit. Some patients with acute retinal necrosis had poor visual acuity at the last visit. CONCLUSIONS: Patients with varicella, herpes zoster ophthalmicus, and acute retinal necrosis had several ocular complications. Some patients with acute retinal necrosis had poor visual outcomes. Ophthalmologists should be aware that acute retinal necrosis may develop shortly after varicella infection.

Rhodopsin promoter-EGFP fusion transgene expression in photoreceptor neurons of retina and pineal complex in mice.

Light detection in vertebrate eyes is mediated through retinal photoreceptor rod and cone cells that transduce light signals into electrical responses. The differentiation and synaptogenesis of photoreceptor cells are especially important since these cells are the main targets of degeneration in retinitis pigmentosa. We produced transgenic mice that express enhanced green fluorescent protein (EGFP) under the control of the mouse rhodopsin gene promoter. In Western blot analyses of transgenic retinal homogenates, expression of the endogenous rhodopsin gene was detected from post-natal day (P)8; however, EGFP expression in transgenic retinas was initially detected at P12, indicating delayed expression of the transgene. At P14, fluorescence microscopy showed a weak expression of EGFP in the transgenic retina. In the adult transgenic mice, the strongest EGFP expression was observed in the outer nuclear layer, and to a lesser extent in the outer plexiform layer as well as in the inner and outer segments. EGFP expression was also observed in the pineal stalk. The rhodopsin promoter-EGFP transgenic mice will be not only useful to assess rhodopsin gene promoter activity in vivo, but also for retinal transplant studies as a source of functional photoreceptor cells that are fluorescent green.