Objective: To establish a prenatal non-invasive method for combined detection of fetal ABO, RhD, and RhCE blood group genotypes based on fluorescence quantitative PCR (FQ-PCR) technology, and to evaluate its clinical value in the early prenatal diagnosis of hemolytic disease of the fetus and newborn (HDFN). Methods: A total of 200 high-risk singleton pregnant women who underwent prenatal examinations in our hospital from January 2022 to December 2024 were prospectively enrolled. They were divided into four groups: the ABO incompatibility group (n=100), the RhD incompatibility group (n=50), the RhCE incompatibility group (n=50), and the control group (n=200). FQ-PCR technology was used to detect cell-free fetal DNA (cff-DNA) in maternal plasma, targeting the ABO system (261delG, 796C>A), exons 5/7 of the RHD gene, and the key loci of RhCE system (C/c, E/e). After delivery, the blood group of newborn was verified by serological testing of umbilical cord blood., and the hemolysis panel tests (direct antiglobulin test, free antibody test, and antibody release test) were performed to evaluate the detection consistency and identify high-risk factors. Results: The detection coincidence rates for ABO, RhD, and RhCE blood groups were 98.0% (98/100), 100.0% (50/50), and 96.0% (48/50), respectively. The incidence of HDFN in the ABO incompatibility group was 69.0% (69/100), which is significantly higher than that in the RhD incompatibility group (10.0%, 5/50) and the RhCE incompatibility group (2.0%, 1/50). Multivariate analysis identified maternal blood type O (OR=3.021), maternal RhD-negative (OR=5.253), and maternal age ≥35 years (OR=1.950) as independent risk factors for HDFN (all P<0.05). Conclusion: Prenatal non-invasive combined detection of multiple blood group antigen genotypes can significantly improve the efficiency of early diagnosis of HDFN and provide accurate early warning for high-risk pregnant women.

Objective To explore the mechanism by which puerarin alleviates the cardiotoxicity induced by doxorubicin in myocardial cells. Methods Cells in the logarithmic growth phase were divided into normal control group,model group,low-(20 mmol·L-1),medium-(40 mmol·L-1) and high-(80 mmol·L-1) dose puerarin groups,and positive control group(captopril,1 mmol·L-1). Except for the normal control group,the other groups were co-incubated with 5 mmol·L-1 doxorubicin. Cell viability was assessed using CCK-8 and lactate dehydrogenase (LDH) assays. ROS levels were detected using a ROS probe. Autophagy flux was detected by transfection with HBAD-mcherry-EGFP-LC3 adenovirus. Western Blot was used to measure the protein expression levels of Beclin-1,LC3,p62,p-AMPKα,and AMPKα. Lysosomal function was assessed using a lysosomal probe. Immunofluorescence was used to detect the relative intensity and co-localization of ASMase and LAMP1. Molecular docking analysis was performed to predict the binding capacity of PUE with ASMase. Differential gene expression was analyzed by gene set enrichment analysis. Results Compared to the normal control group,the model group showed reduced cell viability (P<0.01),increased release levels of LDH and ROS (P<0.05,P<0.01),increased number of autophagosomes (P<0.01),and decreased number of autophagic lysosomes (P<0.05). Beclin-1 protein expression and LC3-II/LC3-I ratio decreased(P<0.01),but p62 protein expression increased(P<0.01). Fluorescence intensity of lysosome decreased(P<0.01),whereas fluorescence intensity of ASMase increased(P<0.01). Immunofluorescence co-localization of ASMase and LAMP1 increased (P<0.01),the ratio of p-AMPKα/AMPKα decreased(P<0.05). Compared to the model group,the high-dose puerarin group showed a rebound in cell viability (P<0.05). The medium-and high-dose puerarin groups showed a decreasing trend in LDH level (P<0.05),and all puerarin groups showed a decreasing trend in ROS level (P<0.01). The number of autophagosomes in high-dose puerarin group reduced (P<0.01). The number of autophagic lysosomes in all puerarin groups increased (P<0.05,P<0.01). The high-dose puerarin group showed increased expression of Beclin-1 (P<0.05) and LC3-II/LC3-I ratio,and decreased p62 expression (P<0.01). All puerarin groups showed increased lysosomal fluorescence intensity (P<0.05,P<0.01). The medium-and high-dose puerarin groups showed a decrease in ASMase fluorescence intensity(P<0.05),a reduction in the immunofluorescence co-localization of ASMase with LAMP1 (P<0.01),and an increase in the p-AMPKα/AMPKα ratio (P<0.01). Molecular docking analysis discovered puerarin showed a binding energy of-8.6 kcal·mol-1 with ASMase. Gene enrichment analysis indicated that the differentially expressed genes in the doxorubicin cardiotoxicity model were related to apoptosis,autophagy,and lysosomal function. Conclusion Puerarin can alleviate doxorubicin-induced cardiotoxicity in myocardial cells and protect myocardial cells by regulating autophagy through AMPK/ASMase,as well as restoring autophagic flux.

N-methyladenosine (mA), a ubiquitous RNA modification, is installed by METTL3-METTL14 complex. The structure of the heterodimeric complex between the methyltransferase domains (MTDs) of METTL3 and METTL14 has been previously determined. However, the MTDs alone possess no enzymatic activity. Here we present the solution structure for the zinc finger domain (ZFD) of METTL3, the inclusion of which fulfills the methyltransferase activity of METTL3-METTL14. We show that the ZFD specifically binds to an RNA containing 5'-GGACU-3' consensus sequence, but does not to one without. The ZFD thus serves as the target recognition domain, a structural feature previously shown for DNA methyltransferases, and cooperates with the MTDs of METTL3-METTL14 for catalysis. However, the interaction between the ZFD and the specific RNA is extremely weak, with the binding affinity at several hundred micromolar under physiological conditions. The ZFD contains two CCCH-type zinc fingers connected by an anti-parallel β-sheet. Mutational analysis and NMR titrations have mapped the functional interface to a contiguous surface. As a division of labor, the RNA-binding interface comprises basic residues from zinc finger 1 and hydrophobic residues from β-sheet and zinc finger 2. Further we show that the linker between the ZFD and MTD of METTL3 is flexible but partially folded, which may permit the cooperation between the two domains during catalysis. Together, the structural characterization of METTL3 ZFD paves the way to elucidate the atomic details of the entire process of RNA mA modification.