Regulation effects of Ngn2 gene transfection on retinal neuron differentiation in three-dimensional optic vesicle of mice / 中华实验眼科杂志

Objective To investigate the regulation effects of Ngn2 gene transfection on retinal neuron differnetion in three-dimentional optic vesicle (OV) of mice.Methods OV was cultured in vitro using mouse induced pluripotent stem cells (iPSC) under specific conditions.During OV culture,it was transfected multiple times by lentivirus-mediated Ngn2 gene and then it was induced after maturation.The cells were specificly differentiated toward retinal nerve cells in OV.Using the green fluorescent protein (EGFP) gene as control,the differentiation of retinal nerve cells in OV was detected by immunohistochemistry.Reverse transcription PCR and Western blot were used to quantitatively detect the expressions of retinal neuron-specific proteins Pax6,Islet1 and Brn3b.Results The mouse iPS-derived OV was successfully cultured.The number of neural cells in the OV transfected with the Ngn2 gene was increased by the lentiviral-mediated lentivirus.The expressions of PAX6,Islet1 and Brn3b in the Ngn2 transfection group were significantly higher at the gene and protein levels than those in the control group,with significant differences between the two groups (P＜0.05).Conclusions The Ngn2 gene can effectively increase the number of retinal neuron differentiation in OV and make in vitro cultured OV more mature and form a more perfect retinal cell neural circuit.

Pattern of Wnt ligand expression during chick eye development

The dorsoventral axis of the eye is determined prior to optic cup invagination. A variety of signaling pathways have been implicated in the maintenance of the optic dorsoventral axis, including, but not limited to, bone morphogenetic protein 4, Sonic Hedgehog and retinoic acid. Here, we investigated the possible contribution of Wnt ligands to the establishment or maintenance of the optic axis by analyzing their expression pattern during early chick optic development. We performed in situ hybridization of Wnt-1, Wnt-3a, Wnt-4, and Wnt-5a during the optic vesicle, early optic cup and established optic cup stages and focused our analysis on the optic region. Our data showed that Wnt-5a, but none of the others, is expressed in the dorsal region of the eye starting from the Hamburger and Hamilton stage 14 (HH14). These results are supported by cryosections of the labeled optic region, which further reveal that Wnt-5a is expressed only in the dorsal retinal pigmented epithelium. Thus, we propose that Wnt-5a is a marker for dorsal retinal pigmented epithelium in chick embryos from HH14 to HH19.

The Effect of X -irradiation on Lens Development / 체질인류학회지

For the study the effects of X -ray irradiation on the development of lens and interactions between optic vesicle and lens, 200 rads X -ray irradiated to the preganat rats (Sprague -Dawley strain) on gestation day 9.5. The rats were sacrificed daily from the gestation day 10.5 to 17.5, and investigated the development of lens with light microscope. The results were as follows; 1. The survival rate of X -irradiated rat fetuses was decreased significantly compared with that of the control group. 2. The mean body weight of the X -irradiated rat fetuses was decreased significantly compared with that of the control group. 3. The congenital anomalies of the eye in the rat fetuses after X -irradiation were anophthalmia, congenital aphakia, lens aplasia, lens luxation, and coloboma of the retina. 4. The critical period of lens development of the Sprague -Dawley rats was considered from GD 9. 5 to GD 10.0. 5. In the X -irradiated rat fetuses on gestation day 9.5, optic vesicle did not developed, but lens developed independently , and moved deeply toward the forebrain vesicle. According to above results, it could be concluded that the development of lens from surface ectoderm might be independent from the inductive influence of optic vesicle, and the movement of lens toward the forebrain vesicle could be mediated by chemotactic factors secreted from the brain vesicle. Further studies are needed to reveal the mechanisms of lens development and interaction between lens and brain vesicle.

Microphthalmia with Orbital Cyst: Case Presentation

A microphthalmia with orbital cyst resulting from a failure in the involution of primary optic vesicle or defective closure of embryonic cleft is rare congenital anomaly. Clinical features are variable and mainly depend upon the time of arrest in development of the embryonic eyeball The authors have experienced a case of microphthamia with1uge orbital cyst in left orbit. The patient was 4 months of age and it was found at the time of birth. At radiologic study an area of suspicious defect in the orbital roof was shown. The orbital cyst and small eyeball were removed by intracranial approach and histopathologic examination was performed with serial section. We could find a suspicous site of defective closure of embryonic cleft and also ectopic retinal tissue in the cystic wall. A disorganized ocular tissues forming tumor like mass filled with microphthalmic eyeball. No cornea, iris or anterior chamber was found in the slide. In view of those histopathologic findings we can suspect that the defective closure of embryonic cleft occured at 7 to 14 mm embryo stage.