Case report: Exotropia in waardenburg syndrome with novel variations.

Background: Waardenburg syndrome (WS) is a rare genetic disorder characterized by congenital sensorineural hearing loss and pigmentary abnormalities of the hair, skin and eyes. However, exotropia is rarely reported. The purpose of this study is to describe the clinical characteristics of three sporadic patients with WS and congenital exotropia and to investigate the disease-causing genes for them. Methods: Patients underwent detailed physical and ocular examinations. Ocular alignment and binocular status were evaluated. DNA was extracted and whole exome sequencing was performed to detect the pathogenic variations in the disease-causing genes for WS. Cloning sequencing was carried out for those indel variations. Results: Three unrelated patients were diagnosed with Waardenburg syndrome and congenital exotropia. Four novel variants, including c.136delA (p.I46Sfs*64) and c.668G>T (p.R223L) in PAX3, c.709dupC (p.Q237Pfs*119) in COL11A2, c.426G>A (p.W142X) in SOX10 gene, were detected in this study. Conclusion: Simultaneous presence of congenital exotropia and WS in our patients is suggested that WS could be involved in malfunction in the multiple nerve systems. Our genetic study will expand the mutation spectrum of PAX3, COL11A2 and SOX10 genes, and is helpful for further study on the molecular pathogenesis of WS.

Expression and role of autophagy related protein p62 and LC3 in the retina in a rat model of acute ocular hypertension.

AIM: To investigate the expression and possible role of the autophagy related protein p62 and LC3 in the retina based on a rat model of acute ocular hypertension. METHODS: Fifty rats were randomized into five groups: control group A, B, C, and D. Groups A to D all received normal saline perfusion into the anterior chamber with pressure of 80 mm Hg for one hour, and retina tissue was obtained at 6, 12, 24 and 48h after perfusion respectively, to investigate the activation of autophagy following ischemia-reperfusion. The distribution and semi-quantification of autophagy related protein p62 and LC3 in the retina were detected using immunohistochemistry technique. The expression level of these two proteins was evaluated using Western blot. RESULTS: The number of retinal ganglion cells (RGCs) decreased with increasing reperfusion time, and significant reduction in the retinal thickness was observed 48h after perfusion. In normal adult rats, LC3 protein was mainly expressed in the ganglion cell layer (GCL), and p62 protein was expressed in the nerve fiber layer (NFL), GCL, inner plexiform layer (IPL), inner nuclear layer (INL) and outer plexiform layer (OPL). In comparison to the control group, the expression level of LC3- II was higher in all the experimental groups (P<0.05), with the peak expression at 12h after reperfusion. Additionally, the expression level of p62 was higher in all the experimental groups than the control (P<0.05, except for group A), with the peak level occurred 24h after reperfusion. CONCLUSION: Both p62 and LC3 show low level and uneven expression in the retina of normal adult rats. Acute ocular hypertension can lead to upregulation of LC3- II and p62 expression in the retina. Autophagy flux is damaged 12h after reperfusion, potentially resulting in further loss of RGCs.

Effects of transforming growth factor-ß2 on myocilin expression and secretion in human primary cultured trabecular meshwork cells.

High intraocular pressure (IOP) is a risk factor for primary open-angle glaucoma (POAG). The trabecular meshwork (TM), a reticular tissue in the outflow passage of the aqueous humor (AH), is a major contributor to intraocular outflow resistance. High levels of myocilin (MYOC), which is expressed in the TM, are associated with high IOP. Furthermore, transforming growth factor-ß2 (TGF-ß2) concentrations in human AH are significantly elevated in POAG patients. This study was designed to investigate the effects of TGF-ß2 on MYOC expression and secretion in human primary cultured TM cells. Primary cultured human TM cells were treated with 0 (control group), 1, 10, and 100 ng/mL TGF-ß2 for 12, 24, or 48 h. MYOC mRNA and protein expressions in TM cells and protein secretion in conditioned media were analyzed by semi-quantitative RT-PCR, Western blotting, and enzyme-linked immunosorbent assays (ELISA), respectively. TM cells treated with 1, 10, and, 100 ng/mL TGF-ß2 for 48 h showed higher MYOC mRNA and protein expressions than those in the control group (0 ng/mL TGF-ß2) (all P < 0.05). Treatment with TGF-ß2 for 48 h also induced MYOC secretion in conditioned media in a dose-dependent manner (0 ng/mL: 7.107±1.163 pg/ml; 1 ng/mL: 7.879±1.894 pg/ml; 10 ng/mL: 8.063±1.181 pg/ml; 100 ng/mL: 8.902±0.699 pg/ml; all P < 0.05). In Conclusion, TGF-ß2 induced MYOC expression and secretion in human primary cultured TM cells. Further investigations are required to confirm the involvement of these two factors in POAG pathogenesis.

Hyaluronic acid increases MMP-2 and MMP-9 expressions in cultured trabecular meshwork cells from patients with primary open-angle glaucoma.

PURPOSE: A depletion of hyaluronic acid (HA) in patients' eyes may be associated with primary open-angle glaucoma (POAG), but the exact mechanism remains unclear. We investigated the effect of HA on the expression of matrix metalloproteinases (MMP-2 and MMP-9) in cultured trabecular meshwork cells. METHODS: Trabecular meshwork cells were cultured from trabecular tissues obtained from the POAG patients aged 23 to 45. The mRNA expression of MMP-2 and MMP-9 was determined by reverse transcription-polymerase chain reaction, and the protein expression of MMP-2 and MMP-9 by gelatin zymography analysis and qualified by the gel electrophoresis image analysis in different HA concentrations. RESULTS: The expression of MMP-2 and MMP-9 by the two methods significantly increased with HA concentration in a dose-response manner. Mean values of the MMP-2 expression by the gelatin zymography analysis were 176, 264, 353, and 448 mg/ml, and mean values of the MMP-9 expression were 547, 659, 895, and 1,147 mg/ml, for HA concentration level of 0, 1, 3, and 6 mg/ml, respectively. CONCLUSIONS: In POAG trabecular meshwork cells, the level of HA concentration increases the activities of MMP-2 and MMP-9. The lack of HA in aqueous humor can result in a reduction in activities of MMPs and therefore may be involved in the pathogenesis of POAG.