miR-211 promotes lens epithelial cells apoptosis by targeting silent mating-type information regulation 2 homolog 1 in age-related cataracts

AIM： To detect the expression of miR-211 in age-related cataract tissue, explore the effects of miR-211 on lens epithelial cell proliferation and apoptosis, and identify its target gene.METHODS： This study used real-time quantitative polymerase chain reaction（RT-q PCR） to measure the expression of miR-211 and its predicted target gene [silent matingtype information regulation 2 homolog 1（SIRT1）] in 46 anterior lens capsules collected from age-related cataract patients. Human lens epithelial cell line（SRA01/04） cells were transfected with either miR-211 mimics, mimic controls, miR-211 inhibitors or inhibitor controls, 72 h after transfection, miR NA and protein expression of SIRT1 were measured using RT-qP CR and Western blotting; then cells were exposed to 200 μmol/L H2O2 for 1h, whereupon cell viability was measured by MTS assay, caspase-3 assay was performed. Dual luciferase reporter assay was performed to verify the relationship between miR-211 of SIRT1.RESULTS： Compared to the control group, expression of miR-211 was significantly increased（P〈0.001）, the miR NA and protein expression of SIRT1 were significantly decreased（P〈0.001） in the anterior lens capsules of patients with age-related cataracts. Relative to the control group, SIRT1 miR NA and protein levels in the miR-211 mimic group were significantly reduced, cell proliferation activity significantly decreased, and caspase-3 activity was significantly increased（P〈0.001）. In the miR-211 inhibitor group, SIRT1 miRNA and protein expression were significantly increased, cell proliferation activity significantly increased, and caspase-3 activity was significantly decreased（P〈0.001）. A dual luciferase reporter assay confirmed that SIRT1 is a direct target of miR-211.CONCLUSION： miR-211 is highly expressed in the anterior lens capsules of patients with age-related cataracts. By negatively regulating the expression of SIRT1, miR-211 promotes lens epithelial cell apoptosis and inhibits lens epithelial cell proliferation.

Genetic Analysis of Distorted Segregation Ratio of Mating Types AmongBasidiospores in Lentinula edodes

This study prepared 17 strains of Lentinula edodes, including wild and cultivated strains as materials, and statistically analyzed the ratios of spores from different aspects via mating types＇ analysis and the OWE-SOJ technique. The results from this study first systematically identified skewed expected distribution of mating-type factors segregation in Lentinula edodes spores has commonly statistical meanings in wild and cultivated strains. Genetic analysis of positive and negative parental-recombined fruiting showed that the nuclear type of F1 progeny spores among those strains segregated through theoretical distribution mainly depended on the combined state of parental dikaryons, and the predominant spores were those with the mating type identical to the dikaryotic parent, indicating that the genetic basis of segregation distortion of spores is different from that of protoplast monokaryons in which the B factor takes predominant responsibility for that phenomenon, and it cooperates A factor with B factor to influence the ratio of spores.

Modeling the Structure of Yeast MAT<i>α</i>1: An HMG-Box Motif with a C-Terminal Helical Extension

The yeast MATα1 is required for the activation of α-specific genes in Saccharomyces cerevisiae and thus confers the α-cell identity of the yeast. MATα1 contains a domain called the α-domain which has significant sequence identity to the HMG-box family of proteins. A multiple sequence alignment of several α-domains and various structurally determined HMG-box domains has revealed that both domains possess very similar structural and functional residues. We found that the basic amino acids of the N-terminal loop, the intercalating hydrophobic residues of the first helix, and the hydrophobic residues required for interactions within the core of the protein are remarkably conserved in α-domains and HMG-box proteins. Our generated molecular models suggest that the first and third helix will be shorter and that the HMG-box core is not an isolated domain. The region beyond the conserved HMG-box motif contains an extended helical region for about 20 - 30 amino acids. Structural models generated by comparative modeling and ab initio modeling reveal that this region will add two or more additional α-helices and will make significant contacts to helix III, II and I of the HMG-box core. We were able to illustrate how the extended α-domain would bind to DNA by merging of the α-domain and the LEF-1/DNA complex. The models we are reporting will be helpful in understanding how MATα1 binds to DNA with its partner MCM1 and activates transcription of α-specific genes. These models will also aid in future biophysical studies of MATα1 including the crystallization and structure determination.