Background: Extrinsic aging results from environmental stressors such as UVR or pollutants. While the effects of single pollutants are better understood, those of their combination remain poorly scrutinized. Objective...Background: Extrinsic aging results from environmental stressors such as UVR or pollutants. While the effects of single pollutants are better understood, those of their combination remain poorly scrutinized. Objective: Building on a study showing downregulation of several processes upon co-exposure to B[a]P and UVA, we investigated changes induced by epigenetic marks. Materials and Methods: Human primary fibroblasts and HaCaT cells were exposed to B[a]P and UVA. After 24 hours, exposed and unexposed cells were compared to assess DNA methylation. Focusing on HaCaT, multiplex assays enabled quantifying histone H3 modifications and evaluating four splicing factors (SRSF1, SRSF3, SFPQ, and SF3B1) by immunohistochemical labeling. The expression of keratinocyte-/fibroblast-relevant genes was assessed by RT-qPCR. Finally, the impact of an Arundo donax L. extract added 24 hours before B[a]P-UVA co-exposure was analyzed. Results: Exposure to B[a]P-UVA raised DNA methylation (HaCaT: ×3.6, fibroblasts: ×1.9), an increase prevented by the extract. In HaCaT cells, B[a]P-UVA increases the frequency of S10P (+38%). When exposure was preceded by extract treatment, the frequency of several methylations was impacted. B[a]P-UVA only induced the expression of SRSF1 and SFPQ in HaCaT (+46% and +34%). Treatment with the extract abolished this effect. Co-exposure increases the expression of inflammation-related genes (IL-1α, IL-1β) in HaCaT cells and decreases those of AQP3, KRT15, and SOD2. The extract has little effect on these changes. In primary fibroblasts, exposure to B[a]P-UVA lowered the expression of LOXL2, LUM, and TGFBR2 (−38%, −59%, and −51%, respectively), and the extract did not affect these modifications. Conclusion: Within 24 hours, a single B[a]P-UVA co-exposure changes epigenetic marks of skin cells but has only mild effects on gene expression. An Arundo donax L. extract can prevent part of the epigenetic marks’ changes and could stimulate the expression of some genes in primary fibroblasts.展开更多
The influence regular and mechanisms of rare earth element cerium and aged condition on the propertiesand fracture feature of monotonic tension for aluminum-lithium alloy 2090 were researched. The evident plasti-catio...The influence regular and mechanisms of rare earth element cerium and aged condition on the propertiesand fracture feature of monotonic tension for aluminum-lithium alloy 2090 were researched. The evident plasti-cation effect can be achieved by adding cerium into alloy 2090, and the aged condition has a significant influ-ence on this effect. The plastication effect of cerium at peckaging is strongest, and at underaging and overagingis weader. The mechanisms of strengthening and plastication of cerium for aluminum-lithium alloys were dis-cussed in the theory of the extrinac strengthening and the intrinsic toughening. According to the research results about fracture feature, first the theory of extrinsic strengthening was presented, and then the role of ceri-um on aluminum-lithium alloy 2090 was explored from the unite energy, the anti-phase baundary energy andthe electron bonds.展开更多
文摘Background: Extrinsic aging results from environmental stressors such as UVR or pollutants. While the effects of single pollutants are better understood, those of their combination remain poorly scrutinized. Objective: Building on a study showing downregulation of several processes upon co-exposure to B[a]P and UVA, we investigated changes induced by epigenetic marks. Materials and Methods: Human primary fibroblasts and HaCaT cells were exposed to B[a]P and UVA. After 24 hours, exposed and unexposed cells were compared to assess DNA methylation. Focusing on HaCaT, multiplex assays enabled quantifying histone H3 modifications and evaluating four splicing factors (SRSF1, SRSF3, SFPQ, and SF3B1) by immunohistochemical labeling. The expression of keratinocyte-/fibroblast-relevant genes was assessed by RT-qPCR. Finally, the impact of an Arundo donax L. extract added 24 hours before B[a]P-UVA co-exposure was analyzed. Results: Exposure to B[a]P-UVA raised DNA methylation (HaCaT: ×3.6, fibroblasts: ×1.9), an increase prevented by the extract. In HaCaT cells, B[a]P-UVA increases the frequency of S10P (+38%). When exposure was preceded by extract treatment, the frequency of several methylations was impacted. B[a]P-UVA only induced the expression of SRSF1 and SFPQ in HaCaT (+46% and +34%). Treatment with the extract abolished this effect. Co-exposure increases the expression of inflammation-related genes (IL-1α, IL-1β) in HaCaT cells and decreases those of AQP3, KRT15, and SOD2. The extract has little effect on these changes. In primary fibroblasts, exposure to B[a]P-UVA lowered the expression of LOXL2, LUM, and TGFBR2 (−38%, −59%, and −51%, respectively), and the extract did not affect these modifications. Conclusion: Within 24 hours, a single B[a]P-UVA co-exposure changes epigenetic marks of skin cells but has only mild effects on gene expression. An Arundo donax L. extract can prevent part of the epigenetic marks’ changes and could stimulate the expression of some genes in primary fibroblasts.
文摘The influence regular and mechanisms of rare earth element cerium and aged condition on the propertiesand fracture feature of monotonic tension for aluminum-lithium alloy 2090 were researched. The evident plasti-cation effect can be achieved by adding cerium into alloy 2090, and the aged condition has a significant influ-ence on this effect. The plastication effect of cerium at peckaging is strongest, and at underaging and overagingis weader. The mechanisms of strengthening and plastication of cerium for aluminum-lithium alloys were dis-cussed in the theory of the extrinac strengthening and the intrinsic toughening. According to the research results about fracture feature, first the theory of extrinsic strengthening was presented, and then the role of ceri-um on aluminum-lithium alloy 2090 was explored from the unite energy, the anti-phase baundary energy andthe electron bonds.
