The apoptosis of lens epithehal cells has been proposed as the common basis of cataract formation, with oxidative stress as the major cause. This study was performed to investigate the protective effect of the herbal constituent parthenolide against oxidative stress-induced apoptosis of human lens epithelial （HLE） cells and the possible molecular mechanisms involved. HLE cells （SRA01-04） were incubated with 50 μM H2O2 in the absence or presence of different doses of parthenolide （10, 20 and 50 μM）. To study apoptosis, the cells were assessed by morphologic examination and Annexin V-propidium iodide double staining flow cytometry; to investigate the underlying molecular mechanisms, the expression of caspase-3 and caspase-9 were assayed by Western blot and quantitative RT-PCR, and the activities of caspase-3 and caspase-9 were measured by a Chemicon caspase colorimetric activity assay kit. Stimulated with H202 for 18 h, a high fraction of riLE cells underwent apoptosis, while in the presence ofparthenolide of different concentrations, dose-dependent blocking of HLE cell apoptosis was observed. The expression of caspase-3 and caspase-9 induced by H202 in HLE cells was significantly reduced by parthenolide both at the protein and mRNA levels, and the activation ofcaspase-3 and caspase-9 was also suppressed by parthenolide in a dose-dependent manner. In conclusion, parthenolide prevents HLE cells from oxidative stress-induced apoptosis through inhibition of the activation ofcaspase-3 and caspase-9, suggesting a potential protective effect against cataract formation.
Hangping YaoXiajing TangXueting ShaoLei FengNanping WuKe Yao
Dendritic cells （DCs） play a critical role in initiating the immune response by virtue of their ability tocapture and present antigens to T ceils.^1 Although the precise mechanism by which DCs acquire human immunodeficiency virus （HIV-1） is not completely understood, migration of DCs from the periphery to the draining lymph nodes may enable CD4^＋ T cells to become infected.^2 DC-specific intercellular adhesion molecule 3 grabbing nonintegrin （DC-SIGN, CD209）, a mannose specific C-type lectin receptor on DCs, plays a vital role in this process by binding HIV-gp120 and helping DCs transport HIV from the infection site to the secondary lymph nodes.^3 DC-SIGN related lectin （DC-SIGNR, or L-SIGN, CD209R） shares 77% amino acid identity with DC-SIGN, and is expressed on endothelial cells in the liver, lymph nodes and placental capillaries.^4 Both DC-SIGN and DC-SIGNR are HIV receptors .5
