All-trans retinoic acid regulates the expression of MMP-2 and TGF-ß2 via RDH5 in retinal pigment epithelium cells.

AIM: To investigate the effect of all-trans retinoic acid (ATRA) on retinol dehydrogenase 5 (RDH5), matrix metalloproteinase-2 (MMP-2) and transforming growth factor-ß2 (TGF-ß2) transcription levels, and the effect of RDH5 on MMP-2 and TGF-ß2 in retinal pigment epithelium (RPE) cells. METHODS: After adult RPE cell line-19 (ARPE-19 cells) intervened with gradient concentrations of ATRA (0-20 µmol/L) for 24h, flow cytometry was used to detect the proliferation and apoptosis of cells in each group, and quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect RDH5, MMP-2 and TGF-ß2 mRNA expression. Then, after ARPE-19 cells transfected with three different siRNA targets for 48h, the RDH5 knockdown efficiency of each group and expression of MMP-2 and TGF-ß2 mRNA within them was detected by qRT-PCR. RESULTS: Flow cytometry results showed that ATRA could inhibit the proliferation of RPE cells and promote the apoptosis of RPE cells, and the difference of apoptosis was statistically significant when the ATRA concentration exceeded 5 µmol/L and compared with the normal control group (P=0.027 and P=0.031, respectively). qRT-PCR results showed that ATRA could significantly inhibit the expression level of RDH5 mRNA (P<0.001) and promote the expression of MMP-2 and TGF-ß2 mRNA (P=0.03 and P<0.001, respectively) in a dose-dependent manner, especially when treated with 5 µmol/L ATRA. The knockdown efficiency of RDH5 siRNA varies with different targets, among which RDH5 siRNA-435 had the highest knockdown efficiency, i.e., more than 50% lower than that of the negative control group (P=0.02). When RDH5 was knocked down for 48h, the results of qRT-PCR showed that the expressions of MMP-2 and TGF-ß2 mRNA were significantly up-regulated (P<0.001). CONCLUSION: ATRA inhibits the expression of RDH5 and promotes MMP-2 and TGF-ß2, and further RDH5 knockdown significantly upregulates MMP-2 and TGF-ß2. These findings suggest that RDH5 may be involved in an epithelial-mesenchymal transition of RPE cells mediated by ATRA.

[Effects of straw mulching and phosphorus application on forms and availability of soil phosphorus in hilly dryland of Sichuan, China]. / 秸秆覆盖与施磷对四川丘陵旱地土壤磷形态及有效性的影响.

We conducted a two-factor split-plot experiment to examine the alteration of soil inorganic phosphorus forms and phosphorus availability under straw mulching and phosphorus fertilizer rates. The main factor was straw mulching and non-mulching, while the sub-factor was phosphorus supply rates, including 0, 75, and 120 kg·hm-2. We analyzed the characteristics of phosphorus adsorption-desorption, the content of inorganic phosphorus components and their relationship with available phosphorus in hilly upland purple soil in Sichuan. Results showed that compared with the non-mulching, the maximum phosphorus adsorption capacity of straw mulching was notably decreased by 7.7% and 7.4% in the two experimental years from 2018 to 2020. The degree of phosphorus saturation and readily desorbable phosphorus of straw mulching were remarkably increased by 35.4% and 21.6% in 2019 and 18.6% and 35.2% in 2020, respectively. The maximum buffer capacity of phosphorus was not different between straw mulching and non-mulching. The maximum phosphorus adsorption capacity and maximum buffer capacity of phosphorus were significantly lower, and the degree of phosphorus saturation was notably higher in the phosphorus application treatment than that under no phosphorus treatment. The readily desorbable phosphorus increased with the increases of phosphorus rates. The contents of dicalcium phosphate (Ca2-P), octa-calcium phosphate (Ca8-P) and iron phosphorus (Fe-P) in straw mulching treatment were notably higher than those in non-mulching treatment, whereas the content of aluminum phosphorus (Al-P) significantly lower under the straw mulching. Meanwhile, the contents of occluded phosphate (O-P) and apatite (Ca10-P) tended to decrease in the straw mulching compared with that under the non-mulching. Phosphorus application increased the content of different inorganic phosphorus components. Compared with the non-mulching, soil available phosphorus content and the phosphorus activation coefficient of straw mulching remarkably increased by 23.2% and 21.3% in 2019, and 9.6% and 8.9% in 2020, respectively. Soil available phosphorus content and phosphorus activation coefficient increased with the increases of phosphorus rate. Results of regression analysis showed that the contribution of inorganic phosphorus components to the availability of available phosphorus in purple soil was Ca2-P > Fe-P > Al-P > Ca8-P > Ca10-P > O-P. Therefore, straw mulching combined with a reasonable phosphorus fertilizer rate could promote the decomposition and transformation of insoluble soil phosphorus to moderately active or easily absorbed phosphorus forms, reduce soil phosphorus adsorption, stimulate soil phosphorus desorption, and improve soil phosphorus availability. Based on the economic benefits, phosphate fertilizer application at the rate of 75 kg·hm-2 combined with straw mulching was recommended in Sichuan hilly dryland, which would be more beneficial in improving soil phosphorus availability.

Role of theories in school-based diabetes care interventions: A critical review.

BACKGROUND: Diabetes is one of the most common chronic diseases of childhood. School plays an essential role in the management of student diabetes, which reduces the risk of short- and long-term diabetes complications and ensures that students are well-positioned for optimal academic performance and growth. AIM: The aim of this review was to systematically identify and synthesize the literature concerning theory-based diabetes care interventions in K-12 schools in the United States. It critically assessed the specific role of theories and associated essential constructs in intervention design, implementation, outcome measurement, and evaluation. METHODS: Relevant literature was identified by keyword searches of the Cochrane Library, PubMed, and Web of Science. RESULTS: Four interventions met the eligibility criteria and were included in the review. Of those, two evaluated online diabetes education programs for school personnel and the other two assessed in-person interventions. Three studies adopted a one-group pre-post study design, and the remaining one adopted a one-shot case-study design. Three of the interventions adopted social cognitive theory, and the remaining one was guided by the diffusion of innovations theory. Three studies identified core constructs of a theory as predictors of behavioral change. Two used theory to select or develop intervention techniques. Two studies used theory to customize participant intervention techniques. Two studies discussed their findings in the context of theory. No study used theory to select potential intervention participants. CONCLUSION: In conclusion, despite the value of theory in intervention design and evaluation, theory-based diabetes interventions at school remain scarce. Future research may seek ways to better integrate theory and empirical research.