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The unique patterns of epigenetic modifications appear in mammalian oocyte development. Establishment of these modifications, including DNA methylation and histone modifications, is a complicated but highly ordered process, which is crucial in terms of oocyte maturation and early embryo development in mammals. Therefore, dissecting the mechanisms of epigenetic establishment in oocytes is of great significance to look insight into the principles of reproduction and pathogenesis of related diseases. In this review, we delineate the distribution patterns and dynamic landscapes of DNA methylation as well as histone methylation, acetylation, ubiquitination, phosphorylation and lactylation in mammalian oocyte development represented by mice and humans. Meanwhile, we present a summary and discussion in the matter of the potential relevance among these epigenetic modifications, which are regulated by multiple factors related to biological functions.

The protective effects of pigment epithelium-derived factor (PEDF) against X-ray-induced retinopathy were investigated in vitro and in vivo. The function of PEDF was suppressed using PEDF receptor inhibitors and transfection of siRNA in human retinal pigment epithelium cell line ARPE-19. The decreased expression of PEDF was measured using quantitative fluorescent reverse transcription PCR and ELISA. Cell viability after X-ray exposure was monitored using the CCK-8 method. Both left and right irradiation fields were set up to deliver X-rays to the eyes of mice using a small animal radiotherapy simulation machine. Each field was irradiated with 10 Gy. The total dose was 20 Gy. The saline containing 2 nmol/L PEDF-34, a 34-amino acid fragment at positions 44~77 of the PEDF, was prepared. After irradiation, the mice were treated with eye drops every day for 4 weeks. After 8 weeks, the eyeballs were harvested for HE and TUNEL staining and checked for retinopathy and apoptosis. The results showed that pretreatment via PEDF receptor inhibitors and the reduction of PEDF expression aggravated X-ray-induced cell damage in ARPE-19 cells, while PEDF-34 exerted protective effects against X-ray-induced cell damage. Eight weeks after irradiation with a dose of 20 Gy, the experimental mice demonstrated aberrant morphology in the retinal pigment epithelial cell layer and apoptotic cells in the outer nuclear layer. The PEDF-34-treated group maintained a structurally normal retina and had no apoptotic cells. The current study indicates that PEDF has a protective effect against radiation-induced retinopathy, and the PEDF-34-containing eye drops could alleviate the injury. Our findings may provide an experimental basis for a new treatment approach for radiation retinopathy.

In order to investigate the laws of the laser peening forming process and the effects of laser peening on the surface quality and tensile properties of 5083 aluminum alloy, experiments were conducted utilizing various laser peening paths, energies, and plate thicknesses. Subsequently, laser peening forming experiments were performed on S-shaped and different shapes of aluminum alloy substrates. The impact of different laser peening durations on surface morphology and tensile properties was then analyzed. Results indicated that the largest bending deformation perpendicular to the laser peening path reached 12.5 mm. In cases where the laser peening path was inclined relative to the horizontal direction, torsional deformations were observed in the aluminum alloy plate. For laser energy levels of 5 J, 6 J, and 7 J, deformation amounts were 3.8 mm, 4.9 mm, and 5.4 mm, respectively. Plates with thicknesses of 4 mm exhibited convex deformation, while those with 2 mm thickness showed concave deformation. Furthermore, following one and two laser peening cycles, the residual stresses in the alloy plates were −80 MPa and −107 MPa, the surface hardness increased by 16 HV and 31 HV, the roughness increased by 2.495 μm and 3.615 μm, and the tensile strength increased by 9.5 MPa and 18.5 MPa, respectively. [ABSTRACT FROM AUTHOR]