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ABSTRACTAbnormal expression of long non-coding RNAs (lncRNAs) is associated with the dysfunctions of human trophoblast cells and the occurrence of miscarriage (abnormal early embryo loss). BBC3/PUMA (BCL2 binding component 3) plays significant roles in regulation of cell apoptosis. However, whether specific lncRNAs might regulate BBC3 in trophoblast cells and further induce apoptosis and miscarriage remains completely unclear. Through screening, we identified a novel lnc-HZ12, which was significantly highly expressed in villous tissues of recurrent miscarriage (RM) patients relative to their healthy control (HC) group. Lnc-HZ12suppressed chaperone-mediated autophagy (CMA) degradation of BBC3, promoted trophoblast cell apoptosis, and was associated with miscarriage. In mechanism, lnc-HZ12downregulated the expression levels of chaperone molecules HSPA8 and LAMP2A in trophoblast cells. Meanwhile, lnc-HZ12(mainly lnc-HZ12-SO2 region in F2 fragment) and HSPA8 competitively bound with the 169RVLYNL174patch on BBC3, which prevented BBC3 from interactions with HSPA8 and impaired the formation of BBC3-HSPA8-LAMP2A complex for CMA degradation of BBC3. Thus, lnc-HZ12upregulated the BBC3-CASP9-CASP3 pathway and induced trophoblast cell apoptosis. In villous tissues, lnc-HZ12was highly expressed, CMA degradation of BBC3 was suppressed, and the apoptosis levels were higher in RM vs HC villous tissues, all of which were associated with miscarriage. Interestingly, knockdown of murine Bbc3could efficiently suppress placental apoptosis and alleviate miscarriage in a mouse miscarriage model. Taken together, our results indicated that lnc-HZ12and BBC3 played important roles in trophoblast cell apoptosis and miscarriage and might act as attractive targets for miscarriage treatment.Abbreviation: 7-AAD: 7-aminoactinomycin D; BaP: benzopyrene; BBC3/PUMA: BCL2 binding component 3; ChIP: chromatin immunoprecipitation; CHX: cycloheximide; CMA: chaperone-mediated autophagy; CQ: chloroquine; DMSO: dimethyl sulfoxide; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; HC: healthy control; HSPA8: heat shock protein family A (Hsp70) member 8; IP: immunoprecipitation; LAMP2A: lysosomal associated membrane protein 2; LncRNA: long non-coding RNA; mRNA: messenger RNA; MT: mutant-type; NC: negative control; NSO: nonspecific oligonucleotide; PARP1: poly(ADP-ribose) polymerase 1; RIP: RNA immunoprecipitation; RM: recurrent miscarriage; TBP: TATA-box binding protein; WT: wild-type.

Numerous strategies have been developed to improve the intensity of a luminol electrochemiluminescence (ECL) system due to the low quantum yield of luminol. Notably, considerable research was carried out to improve luminol ECL intensity relying on increasing the concentration of reactive oxygen species (ROS). Herein, a Co–Nx–C electrocatalyst treated with nitric acid or hydrochloric acid (named as Co-POC-O or Co-POC-R, respectively) was in situ prepared on the surface of carbon nanotubes. Surprisingly, compared with Co-POC-R, the Co-POC-O electrocatalyst not only displays excellent oxygen reduction reaction (ORR) performance but also enriches luminol via non-covalent bonds rather than covalent bonds and physical mixing. This method improves the amount of luminol involved in the electrochemical reaction as well as shortens the distance for electron transfer between oxidized luminol and ROS, which significantly enhances the ECL intensity (10-fold higher than that of the bare electrode and 2-fold higher than that of Co-POC-R). The platform realizes highly sensitive dopamine (DA) with a detection limit of 1.0 pM and a linear range from 10 pM to 1.0 nM. In this work, Co-POC-O is both the co-reaction accelerator and carrier material of luminophore species, which provides a new idea to realize ECL signal amplification.

Nanoplastics (NPs), as emerging pollutants, have attracted global attention. Nevertheless, the adverse effects of NPs on female reproductive health, especially unexplained miscarriage, are poorly understood. Defects of trophoblast cell migration and invasion are associated with miscarriage. Migrasomes were identified as cellular organelles with largely unidentified functions. Whether NPs might affect migration, invasion, and migrasome formation and induce miscarriage has been completely unexplored. In this study, we selected polystyrene nanoplastics (PS-NPs, 50 nm) as a model of plastic particles and treated human trophoblast cells and pregnant mice with PS-NPs at doses near the actual environmental exposure doses of plastic particles in humans. We found that exposure to PS-NPs induced a pregnant mouse miscarriage. PS-NPs suppressed ROCK1-mediated migration/invasion and migrasome formation. SOX2 was identified as the transcription factor of ROCK1. PS-NPs activated autophagy and promoted the autophagy degradation of SOX2, thus suppressing SOX2-mediated ROCK1 transcription. Supplementing with murine SOX2 or ROCK1 could efficiently rescue migration/invasion and migrasome formation and alleviate miscarriage. Analysis of the protein levels of SOX2, ROCK1, TSPAN4, NDST1, P62, and LC-3BII/I in PS-NP-exposed trophoblast cells, villous tissues of unexplained miscarriage patients, and placental tissues of PS-NP-exposed mice gave consistent results. Collectively, this study revealed the reproductive toxicity of nanoplastics and their potential regulatory mechanism, indicating that NP exposure is a risk factor for female reproductive health.

N6-methyladenine (6mA), a newly identified epigenetic modification, plays important roles in regulation of various biological processes. However, the effect of 6mA on DNA replication has been little addressed. In this work, we investigated how 6mA affected DNA replication by DNA polymerase of Pseudomonas aeruginosaPhage PaP1 (gp90 exo–). The presence of 6mA, as well as its intermediate hypoxanthine (Hyp), inhibited DNA replication by gp90 exo–. The 6mA reduced dTTP incorporation efficiency by 10-fold and inhibited next-base extension efficiency by 100-fold. Differently, dCTP was preferentially incorporated opposite Hyp among four dNTPs. Gp90 exo–reduced the extension priority beyond the 6mA:T pair rather than the 6mA:C mispair and preferred to extend beyond Hyp:C rather than the Hyp:T pair. Incorporation of dTTP opposite 6mA and dCTP opposite Hyp showed fast burst phases. The burst rate and burst amplitude were both reduced for 6mA compared with unmodified A. Moreover, the total incorporation efficiency (kpol/Kd,dNTP) was decreased for dTTP incorporation opposite 6mA and dCTP incorporation opposite Hyp compared with dTTP incorporation opposite A. 6mA reduced the incorporation rate (kpol), and Hyp increased the dissociation constant (Kd,dNTP). However, 6mA or Hyp on template did not affect the binding of DNA polymerase to DNA in binary or ternary complexes. This work provides new insight into the inhibited effects of epigenetic modification of 6mA on DNA replication in PaP1.

The lumiol-O2electrochemiluminescence (ECL) system constantly emits bright light at positive potential. Notably, compared with the anodic ECL signal of the luminol-O2system, the great virtues of cathodic ECL are that it is simple and causes minor damage to biological samples. Unfortunately, little emphasis has been paid to cathodic ECL, owing to the low reaction efficacy between luminol and reactive oxygen species. The state-of-the-art work mainly focuses on improving the catalytic activity of the oxygen reduction reaction, which remains a significant challenge. In this work, a synergistic signal amplification pathway is established for luminol cathodic ECL. The synergistic effect is based on the decomposition of H2O2by catalase-like (CAT-like) CoO nanorods (CoO NRs) and regeneration of H2O2by a carbonate/bicarbonate buffer. Compared with Fe2O3nanorod (Fe2O3NR)- and NiO microsphere-modified glassy carbon electrodes (GCEs), the ECL intensity of the luminol-O2system is nearly 50 times stronger when the potential ranged from 0 to −0.4 V on the CoO NR-modified GCE in a carbonate buffer solution. The CAT-like CoO NRs decompose the electroreduction product H2O2into OH·and O2·–, which further oxidize HCO3–and CO32–to HCO3·and CO3·–. These radicals very effectively interact with luminol to form the luminol radical. More importantly, H2O2can be regenerated when HCO3·dimerizes to produce (CO2)2*, which provides a cyclic amplification of the cathodic ECL signal during the dimerization of HCO3·. This work inspires developing a new avenue to improve cathodic ECL and deeply understand the mechanism of a luminol cathodic ECL reaction.