Dicer interacts with SIRT7 and regulates H3K18 deacetylation in response to DNA damaging agents.

Dicer participates in heterochromatin formation in fission yeast and plants. However, whether it has a similar role in mammals remains controversial. Here we showed that the human Dicer protein interacts with SIRT7, an NAD(+)-dependent H3K18Ac (acetylated lysine 18 of histone H3) deacetylase, and holds a proportion of SIRT7 in the cytoplasm. Dicer knockdown led to an increase of chromatin-associated SIRT7 and simultaneously a decrease of cytoplasmic SIRT7, while its overexpression induced SIRT7 reduction in the chromatin-associated fraction and increment in the cytoplasm. Furthermore, DNA damaging agents promoted Dicer expression, leading to decreased level of chromatin-associated SIRT7 and increased level of H3K18Ac, which can be alleviated by Dicer knockdown. Taken together with that H3K18Ac was exclusively associated with the chromatin, our findings suggest that Dicer induction by DNA damaging treatments prevents H3K18Ac deacetylation, probably by trapping more SIRT7 in the cytoplasm.

Controlled attenuation parameter for the detection of steatosis severity in chronic liver disease: a meta-analysis of diagnostic accuracy.

BACKGROUND AND AIM: Controlled attenuation parameter (CAP) is a novel ultrasound-based elastography method for detection of steatosis severity. This meta-analysis aimed to assess the performance of CAP. METHODS: PubMed, the Cochrane Library, and the Web of Knowledge were searched to find studies, published in English, relating to accuracy evaluations of CAP for detecting stage 1 (S1), stage 2 (S2), or stage 3 (S3) hepatic steatosis which was diagnosed by liver biopsy. Sensitivities, specificities, and hierarchical summary receiver operating characteristic (HSROC) curves were used to examine CAP performance. The clinical utility of CAP was also evaluated. RESULTS: Nine studies, with 11 cohorts were analyzed. The summary sensitivities and specificities values were 0.78 (95% confidence interval [CI], 0.69-0.84) and 0.79 (95% CI, 0.68-0.86) for ≥ S1, 0.85 (95% CI, 0.74-0.92) and 0.79 (95% CI, 0.71-0.85) for ≥ S2, and 0.83 (95% CI, 0.76-0.89) and 0.79 (95% CI, 0.68-0.87) for ≥ S3. The HSROCs were 0.85 (95% CI, 0.81-88) for ≥ S1, 0.88 (95% CI, 0.85-0.91) for ≥ S2, and 0.87 (95% CI, 0.84-0.90) for ≥ S3. Following a "positive" measurement (over the threshold value) for ≥ S1, ≥ S2, and ≥ S3, the corresponding post-test probabilities for the presence of steatosis (pretest probability was 50%) were 78%, 80% and 80%, respectively; if the values were below these thresholds ("negative" results), the post-test probabilities were 22%, 16%, and 17%, respectively. CONCLUSIONS: CAP has good sensitivity and specificity for detecting hepatic steatosis; however, based on a meta-analysis, CAP was limited in their accuracy of steatosis, which precluded widespread use in clinical practice.

Association between polymorphisms in lysyl oxidase-like 1 and susceptibility to pseudoexfoliation syndrome and pseudoexfoliation glaucoma.

The present knowledge on the association of single nucleotide polymorphisms (SNPs) of lysyl oxidase-like 1 (LOXL1) with pseudoexfoliation syndrome (PEXS) and pseudoexfoliation glaucoma (PEXG) is controversial and inconclusive. This meta-analysis sought to derive a more precise estimation of the effects of LOXL1 SNP loci (rs1048661, rs3825942, and rs2165241) on PEXS/PEXG. Literature searches were conducted on the PubMed, EMBASE, ISI Web of Science, and Cochrane Library databases through October 2013. Twelve studies describing 1810 cases and 1790 controls met the inclusion criteria. The strengths of the associations found through the meta-analysis were assessed with pooled odds ratios and their 95% confidence intervals (CI). A meta-regression analysis was also used to examine the influence of the study and population characteristics. The results indicated that rs1048661 TT carriers had 92.1% and 40.4% less risk of developing PEXS/PEXG than did the controls in the Caucasian and Asian populations, respectively. Carriers of rs3825942 AA or rs2165241 CC also had significantly less PEXS/PEXG susceptibility than did the non-carriers. Meta-regression showed that in Caucasians, the male proportion (slope: 0.272; 95% CI: 0.167-0.376; P = 0.0001) and mean age (slope: 0.796; 95% CI: 0.375-1.217; P = 0.0002) of the PEXS/PEXG subjects correlated positively with the effect of rs3825942 on PEXS/PEXG susceptibility. The meta-analysis suggested that LOXL1 rs1048661 TT, rs3825942 AA, and rs2165241 CC were associated with a reduced risk of developing PEXS/PEXG.