Yu Alice L, Moriniere Jerome, Birke Marco, Neumann Carolin, Fuchshofer Rudolf, Kampik Anselm, Bloemendal Hans, Welge-Lussen Ulrich
Department of Ophthalmology, Ludwig-Maximilians-University, Munich, Germany.
Invest Ophthalmol Vis Sci. 2009 Apr;50(4):1707-17. doi: 10.1167/iovs.08-1961. Epub 2008 Oct 24.
Histologic studies have previously demonstrated increased expression of small heat shock proteins (Hsps) in reactive optic nerve head (ONH) astrocytes of patients with glaucoma. Transforming growth factor (TGF)-beta2 and hydrogen peroxide (H(2)O(2)) are known to induce ONH astrocyte reactivation. The goal of the present study was to determine whether new potentially involved Hsps, such as Hsp32, -47, -60, and -70, are expressed in the reactivation process of ONH astrocytes mediated by TGF-beta2 and H(2)O(2).
Cultured human ONH astrocytes were treated with 1.0 ng/mL TGF-beta2 for up to 48 hours. In addition, the cells were exposed to 100, 200, or 400 microM H(2)O(2) for 1 hour. Expression of Hsp32, -47, -60, and -70 was examined by immunohistochemistry, real-time PCR, and Western blot analyses.
Treatment with TGF-beta2 increased Hsp32 after 4 and 6 hours, whereas Hsp47 was upregulated after treatment with TGF-beta2 for 12, 24, and 48 hours. Exposure of the cells to H(2)O(2) could increase both Hsp32 and -47. No significant effects on the expression of Hsp60 and -70 were observed after treatment of the cells with TGF-beta2 or H(2)O(2).
TGF-beta2 increased Hsp32 after short-term treatment and Hsp47 after longer periods in cultured human ONH astrocytes. H(2)O(2) increased both Hsp32 and -47 levels. No effects on Hsp60 and -70 levels were induced by TGF-beta2 and H(2)O(2). These results may provide further insights into the cellular stress responses of reactive human ONH astrocytes. Further extensive studies are needed to examine the potential roles of Hsps in the ONH of glaucomatous eyes.
组织学研究先前已证明，青光眼患者反应性视神经乳头（ONH）星形胶质细胞中小热休克蛋白（Hsps）的表达增加。已知转化生长因子（TGF）-β2和过氧化氢（H₂O₂）可诱导ONH星形胶质细胞重新激活。本研究的目的是确定新的潜在相关Hsps，如Hsp32、-47、-60和-70，是否在由TGF-β2和H₂O₂介导的ONH星形胶质细胞重新激活过程中表达。
将培养的人ONH星形胶质细胞用1.0 ng/mL TGF-β2处理长达48小时。此外，将细胞暴露于100、200或400 μM H₂O₂中1小时。通过免疫组织化学、实时PCR和蛋白质印迹分析检测Hsp32、-47、-60和-70的表达。
用TGF-β2处理4小时和6小时后Hsp32增加，而用TGF-β2处理12、24和48小时后Hsp47上调。细胞暴露于H₂O₂可增加Hsp32和-47。用TGF-β2或H₂O₂处理细胞后，未观察到对Hsp60和-70表达的显著影响。
在培养的人ONH星形胶质细胞中，短期处理后TGF-β2增加Hsp32，较长时间后增加Hsp47。H₂O₂增加Hsp32和-47水平。TGF-β2和H₂O₂未诱导Hsp60和-70水平的变化。这些结果可能为反应性人ONH星形胶质细胞的细胞应激反应提供进一步的见解。需要进一步广泛研究以检查Hsps在青光眼患者ONH中的潜在作用。
