Curcumin protects trabecular meshwork cells against hydrogen peroxide-induced oxidative stress and apoptosis via Nrf2-keap1 pathway

Purpose: To explore the effects and molecular mechanism of action of curcumin on trabecular meshwork cells (TMCs).Methods: TMCs were isolated from pig eyes and NF-E2-related factor 2 (Nrf2) was knocked down by siRNA transfection. The effect of curcumin on intracellular reactive oxygen species (ROS) was measured by a ROS-specific dye. Annexin V-FITC/propidium iodide (PI) double labeling was applied to determine apoptosis. The expressions of apoptosis-associated proteins and Nrf2-Kelch-like ECHassociated protein 1 (Keap 1) pathway activation were assessed by western blotting, while target gene transcription was analyzed by quantitative real-time polymerase chain reaction (qRT-PCR).Results: Curcumin reduced the levels of intracellular ROS and apoptosis induced by H2O2, upregulated B-cell lymphoma-2 (Bcl-2), downregulated Bcl2-associated X (Bax), and activated caspase-3 and nine other proteins (p < 0.05). Curcumin reduced the expressions of Nrf2, HO-1, and NQO1, and increased Keap1 in H2O2-induced TMCs (p < 0.05). Moreover, Nrf2 knockdown partly reversed the effect of curcumin on ROS and apoptosis in TMCs induced by H2O2 (p < 0.05).Conclusion: Curcumin inhibited oxidative stress and apoptosis by Nrf2-Keap1 activation in TMCs. Curcumin is therefore a potential therapeutic agent for the management of glaucoma.Keywords: Curcumin, Oxidative stress, Apoptosis, Glaucoma, Nrf2-Keap

Gab2 facilitates epithelial-to-mesenchymal transition via the MEK/ERK/MMP signaling in colorectal cancer

Clinicopathologic factors and Gab2 expression in 35 CRC patients. (DOCX 22 kb

Plant Functional Traits Are the Mediators in Regulating Effects of Abiotic Site Conditions on Aboveground Carbon Stock-Evidence From a 30 ha Tropical Forest Plot

Understanding the relative contribution of abiotic and biotic factors to the formation of ecosystem functioning across scales is vital to evaluate ecosystem services. Here, we elucidate the effects of abiotic site conditions (i.e., soil and topographic properties) and plant functional traits on variations of stand aboveground carbon (AGC) stock in an old-growth tropical montane rain forest. The response-effect framework in functional ecology is adopted in examining how plant functional traits respond to environmental changes and affect ecosystem functioning. We measured specific leaf area and wood density of 270 woody plant species and estimated stand AGC stocks in a 30-ha forest plot. The relationships among environmental factors (ENVIRONMENT), community-weighted means of functional traits (TRAITS) and stand AGC stocks across nested spatial scales were disentangled by structural equation modeling. The results showed that the stands composed of ‘acquisitive’ species (high specific leaf area and low wood density) had low AGC, whereas stands composed of ‘conservative’ species (low specific leaf area and high wood density) had high AGC. TRAITS responded to ENVIRONMENT and affected AGC directly. ENVIRONMENT had an indirect effect on AGC through its direct effect on TRAITS. TRAITS were more important than ENVIRONMENT in driving variations of AGC. The effects of TRAITS on AGC increased, while the effects of ENVIRONMENT on AGC decreased with the increase of spatial scales in the tropical montane rain forest. Our study suggests that plant functional traits are the mediators in regulating effects of abiotic site conditions on ecosystem functions