The effects of postmenopausal hormone use on cataract: a meta-analysis.

BACKGROUND:Cataract is the leading cause of blindness worldwide. Many observational studies assessed the relationship between postmenopausal hormone replacement therapy (HRT) and risk of cataract development, but the reported results were controversial. The aim of present meta-analysis was to evaluate the association of postmenopausal hormone replacement therapy with risk of cataract development. METHODS:The eligible observational studies, including cross-sectional, case-control and cohort studies, were identified by searching PubMed and Embase during March of 2013. Either a fixed- or a random-effects model was used to calculate the pooled odds ratio (OR) with its 95% confidence interval (95%CI). Subgroup analysis on cataract types was performed. RESULTS:A total of four cohort and five case-control or cross-sectional studies were finally included into this meta-analysis. Overall, a significant decreased risk of developing any type of cataract was found in ever HRT group as compared with non-HRT group among cohort studies (OR 0.83; 95%CI: 0.71,0.97) and case-control or cross-sectional studies (OR 0.74; 95%CI: 0.59,0.93). Subgroup analysis on cataract types determined that the significantly decreased risk of nuclear cataract in current HRT group (OR 0.72; 95%CI: 0.61,0.85) and also a critically reduced risk of nuclear cataract in ever HRT group (OR 0.80; 95% CI: 0.64,1.01) were found among case-control or cross-sectional studies, as compared with non-HRT group. No association of HRT with risk of cortical and posterior subcapsular cataract was observed. CONCLUSIONS:The results of present meta-analysis indicate that postmenopausal hormone use may play a protective role in cataract development

ERRγ is involved in ANG-regulated cancer cell proliferation and cell cycle protein expression.

<p>(<b>A</b>) MCF-7 cells transfected with siRNAs targeting ANG, ERRγ, or both were seeded at equal density. Cell numbers were counted at each time point as indicated. One-way ANOVA was used for statistical analysis of cell proliferation. (<b>B</b>) MCF-7 cells were transfected with siRNAs targeting ANG, ERRγ, or both and the expression levels of indicated genes were detected with RT-qPCR. (<b>C</b>) MCF-7 cells transfected with siRNAs targeting ANG, ERRγ, or both were applied to ChIP assays with antibodies against RNA Pol II or ERRγ. The antibody enriched DNA were analyzed by qPCR. Values were means±s.d. for triplicates.</p

Identification of Estrogen Receptor-Related Receptor Gamma as a Direct Transcriptional Target of Angiogenin

<div><p>Nuclear translocation of angiogenin (ANG) is essential for the proliferation of its target cells. ANG promotes rRNA synthesis, while whether it regulates mRNA transcription remains unknown. Using the chromatin immunoprecipitation method, we have identified 12 ANG-binding sequences. One of these sequences lies in the estrogen receptor-related receptor gamma (ERRγ) gene which we designated as ANG-Binding Sequence within ERRγ (ABSE). ABSE exhibited ANG-dependent repressor activity in the luciferase reporter system. Down-regulation of ANG increased ERRγ expression, and active gene marker level at the ABSE region. The expression levels of ERRγ targets genes, p21^WAF/CIP and p27^KIP1, and the occupation of ERRγ on their promoter regions were increased in ANG-deficient cells accordingly. Furthermore, knockdown of ERRγ promoted the proliferation rate in ANG-deficient breast cancer cells. Finally, immunohistochemistry staining showed negative correlation between ANG and ERRγ in breast cancer tissue. Altogether, our study provides evidence that nuclear ANG directly binds to the ABSE of ERRγ gene and inhibits ERRγ transcription to promote breast cancer cell proliferation.</p></div

Immunohistochemistry staining of ANG and ERRγ in breast tissue samples.

<p>Tissue microarray slide containing human breast ductal carcinoma tissues (<b>A, B</b>) and adjacent normal breast tissues (<b>C, D</b>) were stained with ANG (<b>A, C</b>) or ERRγ (<b>B, D</b>) antibody and visualized with Dako’s Envision kit. (Magnification: ×100). (<b>E</b>) The roles of ANG in the nucleus. ANG in the nucleolus promotes rRNA production and ribosome biogenesis. Meanwhile, ANG in the nucleoplasm regulates the expressions of its target genes to regulate cancer cell proliferation coordinately.</p

ANG interacts with ABSE fragment in HeLa and MCF-7 cells.

<p>(<b>A</b>) Schematic illustration of ABSE localization in <i>ERRγ</i> gene. (<b>B</b>) HeLa cells were pretreated with or without neomycin for 1 hour and incubated with 1 ug/mL of ANG. Cells were then applied to ChIP experiments with IgG or ANG antibody and analyzed by qPCR. Data shown represents mean±s.d. of three independent experiments. (<b>C</b>) MCF-7 cells were pretreated with or without neomycin for 1 hour and incubated with 1 ug/mL of ANG. Cells were then stained with ANG polyclonal antibodies. Nuclei were stained with DAPI (blue). (<b>D</b>) MCF-7 cells were treated with or without neomycin followed by incubation with 1 ug/mL of ANG. Cells were then applied to ChIP experiments. Data shown represents mean±s.d. of three independent experiments.</p

ANG influences the histone modifications and Pol II occupation at ABSE region.

<p>MCF-7 cells were transfected with siRNA targeting ANG or control siRNA for 72 hours. ChIP assays were performed with antibodies against acetyl-H4 (<b>A</b>), H3K4me2 (<b>B</b>), or RNA Pol II (<b>C</b>) and analyzed by qPCR. Values were means±s.d. for triplicates.</p

ANG regulates the repressive activity of ABSE and ERRγ expression.

<p>(<b>A</b>) Schematic illustration of plasmids used in the luciferase assays. (<b>B</b>) MCF-7 cells were transfected with the indicated plasmids together with siRNAs targeting control or ANG. Luciferase activities were detected 48 hours after transfection. Relative luciferase activity is a ratio of Firefly luciferse units normalized to Renilla luciferase units. (<b>C</b>) MCF-7 cells were treated with siRNA targeting ANG or control for 48 hours. The mRNA levels of <i>ANG</i> and <i>ERRγ</i> were detected by RT-qPCR.</p

Identification of ANG-binding DNA fragments.

<p>(<b>A</b>) Schematic illustration of ChIP screen of ANG-binding DNA. (<b>B</b>) Sonicated chromatin samples from HeLa cells were immunoprecipitated overnight with ANG antibody or IgG and applied to Western blot analysis. Data showed specific enrichment of ANG in the antibody group.</p

Information of ANG-binding fragments identified by ChIP-cloning.

<p>Information of ANG-binding fragments identified by ChIP-cloning.</p