Effect of Aralia Elata on the Expression of Hyperosmolarity-induced TonEBP Protein and Inflammatory Mediators in Corneal Epithelial Cells

Purpose@#To investigate the effect of Aralia elata (AE) on hyperosmolar stress-induced tonicity response enhancer-binding protein (TonEBP) expression and changes in the levels of proinflammatory cytokines in immortalized human corneal epithelial cells (hCECs). @*Methods@#Immortalized hCECs were cultured with either 5 or 10 μg/mL AE for 24 hours, and the medium then changed to a hyperosmotic medium (500 mOsM/L). After hyperosmolar treatment, cell viability and wound-healing assays were performed, and cell proteins subjected to Western blot analysis, immunocytochemistry for TonEBP and NF-κB, and tests measuring changes in the levels of oxidative stress markers and inflammatory mediators. @*Results@#AE pretreatment ameliorated hyperosmolarity-induced cell death and the delay in wound-healing in a dose-dependent manner. AE inhibited TonEBP and phospho-NF-κB p65 subunit upregulation. AE significantly decreased the expression levels of Bax, 4-HNE, and IL-1β; but increased those of Bcl-2, Bcl-xl, and Gpx. @*Conclusions@#AE increased cell viability and wound-healing, and inhibited the hyperosmolar stress-induced upregulation of TonEBP and NF-κB. AE may be useful for treatment of patients with certain ocular surface diseases.

Involvement of VEGF in both Cell Apoptosis and Survival in the Retina of Type 2 Diabetic OLETF Rats / 대한해부학회지

Vascular endothelial growth factor (VEGF) is closely involved in early retinal pathology of diabetes, including blood-retinal barrier breakdown, pericyte loss, neuro-retinal apoptosis, and cell proliferation. This study examines the involvement of VEGF in cell apoptosis and survival in the retina of animals with type 2 diabetes. We used retinas from 28-week-old Otsuka Long-Evans Tokushima Fatty (OLETF) rats, a model of spontaneous type 2 diabetes, and Long-Evans Tokushima Otsuka (LETO) rats as controls. In parallel with evidence for pericyte loss, we found cell proliferation, apoptosis, and endothelial nitric oxide synthase (eNOS) (an indicator of endothelial cell proliferation/survival) and VEGF overexpression in the OLETF-retina, compared to control LETO. Furthermore, apoptotic signals were partly co-localized to only VEGF-positive cells in the OLETF-retina, but no apoptotic signals were found in VEGF- and eNOS-double-positive cells. These results suggest that upregulated VEGF is involved in apoptosis and eNOS-dependent cell survival in the retinas of type 2 diabetic rats.

Alterations of Tyrosine Hydroxylase and Choline Acetyltransferase in the Retina of the Diabetic Rat / 대한해부학회지

To investigate the effect of hyperglycemia on the visual system, we investigated the retinal dopaminergic and cholinergic systems using tyrosine hydroxylase (TH) and choline acetyltransferase (ChAT) in the rat retinas of streptozotocin (STZ)-induced diabetes. Diabetes was induced by a single intraperitoneal injection of STZ (50 mg/kg) to Sprague-Dawley rats (250~300 g). We first analyzed morphologic thickness changes in the several retinal layers of 6-week-old control and STZ-diabetic rats after H & E staining. To confirm whether TH and ChAT protein expressions changed, we carried out immunohistochemistry analysis and Western blotting. After induction of diabetes, significant changes were not shown in the retinal thickness at 6 weeks. TH and ChAT immunoreactivities were clearly detected in amacrine cells and sublaminas in the inner retina of both control and diabetic rats, showing continuously reduced positive amacrine cells in the retinas during diabetes. In addition, the decline in TH and ChAT protein expression was already present to a significant extent in the retina at 6 weeks in early diabetes. Our present study demonstrates the possibility that the observed alterations in TH and ChAT in the diabetic retina may cause the visual system changes in the retinal pathophysiology associated with diabetes mellitus.