MiRNA-494 induces trophoblast senescence by targeting SIRT1

Objective Although the mechanism underlying preeclampsia (PE) has been widely explored, the mechanisms related to senescence have not yet been fully revealed. Therefore, we investigated the role of the miR-494/longevity protein Sirtuin 1 (SIRT1) axis in PE. Methods Human placental tissue was obtained from severe preeclampsia (SPE) (n = 20) and gestational age-matched normotensive pregnancies (n = 20), and senescence-associated β-galactosidase (SAβG) and SIRT1 expression levels were measured. The TargetScan and miRDB databases predicted candidate miRNAs targeting SIRT1, and intersected with differentially expressed miRNAs in the GSE15789 dataset (p < 0.05, |log2FC|≥1.5). Subsequently, we showed that miRNA (miR)-494 expression was significantly elevated in SPE, revealing miR-494 as a candidate SIRT1-binding miRNA. A dual-luciferase assay confirmed the targeting relationship between miR-494 and SIRT1. The senescence phenotype, migration, cell viability, reactive oxygen species (ROS) production levels and inflammatory molecule expression levels were measured after miR-494 expression was altered. We conducted a rescue experiment using SIRT1 plasmids to further demonstrate the regulatory relationship. Results SIRT1 expression was lower(p < 0.01) and miR-494 expression was higher (p < 0.001) in SPE, and SaβG staining showed premature placental aging in SPE (p < 0.001). Dual-luciferase reporter assays revealed that miR-494 targeted SIRT1. Compared to control cells, HTR-8/SVneo cells with upregulation of miR-494 had remarkably downregulated SIRT1 expression (p < 0.001), more SAβG-positive cells (p < 0.001), cell cycle arrested (p < 0.05), and upregulated P21 and P16 expression (p < 0.01). miR-494 overexpression also decreased HTR-8/SVneo cell migration (p < 0.05) and ATP synthesis (p < 0.001), increased ROS levels (p < 0.001), and upregulated NLRP3 and IL-1β expression (p < 0.01). SIRT1-overexpressing plasmids partially reversed the effects of miR-494 overexpression in HTR-8/SVneo cells. Conclusion The miR-494/SIRT1 interaction plays a role in the mechanism of premature placental aging in PE patients

Acetylacetone Spectrophotometric Determination of Formaldehyde Content in Vegetables and Risk Assessment

【Objective】The study was conducted to establish a fast method for the detection of formaldehyde content in vegetables, identify the residue level and understand the dietary exposure risk of formaldehyde in vegetables.【Method】The single factor experiment was used to optimize the key experimental conditions, and then a method acetylacetone spectrophotometry for the detection of formaldehyde contents in vegetables was established. The formaldehyde contents of 383 vegetable samples were analyzed and the exposure risk of formaldehyde in vegetables was assessed with point evaluation method.【Result】The detection limit and the quantitation limit for the determination of formaldehyde in vegetables with acetylacetone spectrophotometry were 0.45 and 1.5 mg/kg, respectively; At the added levels of 1.5, 7.5 and 15 mg/kg, the recovery rates ranged from 86.33% to 92.4% with the relative standard deviations were of 2.23%-4.21%. The detection rates of formaldehyde in different vegetables were 5.00%-72.73% with the total detection rate of 26.37%, and the average detection values of different vegetables were 0.47-1.67 mg/kg. The dietary exposure levels of formaldehyde contents in different vegetables to the general population ranged from 0.0019 to 0.068 mg/kg (bw/d) with the MOS ranging from 14.1 to 289.8, and the dietary exposure levels of formaldehyde contents in vegetables to different populations were 0.0060-0.15 mg/kg (bw/d) with the MOS ranging from 10.1 to 33.3. All the evaluated values of MOS were greater than 1.【Conclusion】The method of acetylacetone spectrophotometry is simple, accurate and sensitive, which is suitable for the fast determination of formaldehyde in vegetables. The dietary intake risk of formaldehyde residues in vegetables is low and within the acceptable range