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N6-methyladenosine (m6A) is the most abundant mRNA internal modification in eukaryotic mRNAs. This study focuses on the effect of circMPP1 on placental villi function and the molecular mechanism. First, differentially expressed circular RNAs (circRNAs) in placenta tissues of large-for-gestational-age(LGA) neonates were screened by m6A-circRNA Epitranscriptomic Microarray and bioinformatics analyses. The abnormal expression of circMPP1 in placental tissues and cell lines was validated by RT-qPCR. In-vitro and in-vivo functional experiments were performed to evaluate the role of circMPP1 in placental impairment and fetal dysplasia. The interacting proteins of circMPP1 were identified and validated using RNA pull-down, RNA immunoprecipitation, fluorescence in situ hybridization, and immunofluorescence experiments. Protein interactions and expression levels were detected by Co-immunoprecipitation and western blot analysis. The m6A modification in circMPP1 was verified by methylated RNA immunoprecipitation assay. Bioinformatics analyses showed that circMPP1 was highly expressed in tissues with disordered placental function. In-vitro and in-vivo functional experiments showed that circMPP1 inhibited the function of placental villi. Further mechanism analyses showed that circMPP1 activated the NF-kappa B and MAPK3 signaling pathways. In addition, the m6A "reader" protein YTHDC1 was found to reduce circMPP1 expression via m6A modification. In conclusion, this study demonstrates that YTHDC1 maintains trophoblasts function by promoting degradation of m6A-mediated circMPP1., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Preeclampsia (PE) is an obstetric disorder. N6-methyladenosine (m6A) modification is related to PE trophoblast biological behaviors. This study explored the mechanism of m6A-modified circSETD2 in trophoblast biological behaviors. Chorionic trophoblast apoptosis and circSETD2 expression in PE rat models were detected. HTR8/SVneo cells were induced by CoCl 2 to establish PE trophoblast models. circSETD2 was silenced or overexpressed to evaluate its effect on cell proliferation, invasion, and apoptosis. m6A level of circSETD2 in trophoblasts was changed by pcDNA3.1-METTL3 and pcDNA3.1-FTO. The targeting relations among miR-181a-5p, circSETD2, and MCL1 were verified by dual-luciferase assay. miR-181a-5p and MCL1 expressions were interfered with to confirm the effect of m6A-modified circSETD2. m6A methylation level was changed in PE rats for in vivo validation. PE rats showed diminished circSETD2 expression and increased apoptosis index. circSETD2 overexpression promoted trophoblast proliferation and invasion, and reduced apoptosis. METTL3 overexpression increased total m6A, circSETD2 m6A, and circSETD2 levels. m6A modification mediated circSETD2 upregulation. circSETD2 was a sponge of miR-181a-5p to elevate MCL1 transcription. miR-181a-5p overexpression or MCL1 silencing annulled the role of m6A-modified circSETD2. circSETD2 inhibition negated suppression of METTL3 overexpression on chorionic trophoblast apoptosis in vivo. Collectively, m6A modification of circSETD2 suppressed miR-181a-5p and increased MCL1 transcription, thus regulating trophoblasts., (© 2022 Wiley Periodicals LLC.)

Background: The role of repeat cerclage (RC) among patients with prolapsed membranes remains controversial. We aimed to investigate the effectiveness of RC and assess the correlation between clinical factors and pregnancy outcome following RC., Methods: The clinical data of patients who underwent RC for prolapsed membranes after prior cerclage were retrospectively investigated. The clinical characteristics of patients were compared between singleton and twin pregnancies. The clinical characteristics of singleton pregnancies were compared between the gestational age (GA) at delivery <28 weeks' and ≥28 weeks' groups. Receiver operating characteristic (ROC) curve analysis was performed to determine predictive factors. Singleton patients were divided into two groups according to GA at RC as follows: GA <22.3 weeks and GA ≥22.3 weeks. Pregnancy outcomes were compared between groups., Results: The mean GA at delivery of singleton pregnancies was significantly higher than that of twin pregnancies. The mean latency between RC and delivery of singleton pregnancies was significantly longer than their twin counterparts. There were significant differences in the pregnancy outcomes between the GA <22.3 weeks group and GA ≥22.3 weeks group. Kaplan-Meier survival curves showed a lower incidence of neonatal death in the GA ≥22.3 weeks group compared with that in the GA <22.3 weeks group., Conclusions: RC may be an effective method to prolong the duration of pregnancy among patients with singleton pregnancy. However, the selection of RC for patients with twin pregnancies remains controversial. GA at RC appears to be fair for predicting pregnancy outcomes following RC., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Cai, Xia and Na.)

We investigate the bleaching of two-photon absorption by single-photon excitation using femtosecond transient absorption measurements on the prototypical polyfluorene (F8), and thus introduce single-photon pumping and two-photon probing spectroscopy for the determination of absorption cross-sections in an organic semiconductor. Single-photon excitation at 3.1 eV rearranges the population distributions on the singlet excited state (1Bu) and on the ground state (1Ag), and probe pulses at 1.55 eV will thus be absorbed both by the singlet excited state through a single-photon process and by the partially depopulated ground state for two-photon transition from 1Ag to mAg. As a result, the two-photon absorption will be partially bleached, introducing a modulation to the total transient absorption. Probe intensity dependence of the transient absorption enables simultaneous determination of the two-photon absorption (mAg?1Ag) and exciton absorption (kAg?1Bu) cross-sections at 1.55 eV.