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MEIOB is a vital protein in meiotic homologous recombination and plays an indispensable role in human gametogenesis. In mammals, MEIOB and its partner SPATA22 form a heterodimer, ensuring their effective localization on single-strand DNA (ssDNA) and proper synapsis processes. Mutations in human MEIOB (hMEIOB) cause human infertility attributed to the failure of its interaction with human SPATA22 (hSPATA22) and ssDNA binding. However, the detailed mechanism is still unclear. In our study, truncated or full-length hMEIOB and hSPATA22 are traced by fused expression with fluorescent proteins (i.e., copGFP or mCherry), and the live cell imaging system is used to observe the expression and localization of the proteins. When transfected alone, hMEIOB accumulates in the cytoplasm. Interestingly, a covered NLS in the OB domain of hMEIOB is identified, which can be exposed by hSPATA22 and is necessary for the nuclear localization of hMEIOB. When hSPATA22 loses its hMEIOB interacting domain or NLS, the nuclear localization of hMEIOB is aborted. Collectively, our results prove that the NLS in the OB domain of hMEIOB and interaction with hSPATA22 are required for hMEIOB nuclear localization.

AbstractMicrobial oil recovery (MEOR) technology has a wide application prospect in the field of enhanced oil recovery in low-permeability reservoirs, and genetic engineering plays an important role. At present, oil-production engineering bacteria constructed by genetic engineering are mainly used to obtain high metabolites and strong environmental adaptability; there are few reports on genetically engineered bacteria with different functional metabolites. However, the bacteria which could efficiently produce one metabolite have a poor ability to produce other metabolites. Therefore, in order to reduce the cost of nutrients and improve the effect of microbial oil recovery, dual-metabolite bacteria have been constructed for low-permeability reservoir. In this paper, four rhamnolipid expression plasmids are extracted from E. coli-produced biosurfactant. Then, the rhamnolipid expression plasmids are transferred into the bacteria-produced biopolymer by electrotransformation, and the metabolite performance of the constructed bacteria is evaluated. Finally, the profile control and displacement performance of the constructed bacteria are studied through low-permeability core experiments. The experimental results show that three bacteria, WS1, WS2, and WS3, are successfully constructed that have preferable ability, among which the bacteria WS2 has the best capacity for producing biopolymer and biosurfactant at the same time. After culturing 96 h, the viscosity of the bacteria WS2 fermentation broth could increase to 42.1 mPa·s, and the surface tension and interfacial tension of the fermentation broth could decrease to 24.3 mN/m and 0.035 mN/m, respectively. This time-varying biological viscosity ensures that the microbial system can enter the low-permeability reservoir at a low injection pressure, and the oil recovery of the low-permeability core could be increased by 10.18% after injecting 0.5 PV WS2 microbial system. The findings of this study can help for better understanding of gene construction and technical support for further popularization and application of MEOR in low-permeability reservoirs.

Vascular smooth muscle cells (VSMCs) are an important source of foam cells in atherosclerosis. The mechanism for VSMC-derived foam cell formation is, however, poorly understood. Here, we demonstrate that the P2RY12/P2Y12 receptor is important in regulating macroautophagy/autophagy and VSMC-derived foam cell formation in advanced atherosclerosis. Inhibition of the P2RY12 receptor ameliorated lipid accumulation and VSMC-derived foam cell formation in high-fat diet-fed apoe-/- mice (atherosclerosis model) independent of LDL-c levels. Activation of the P2RY12 receptor blocked cholesterol efflux via PI3K-AKT, while genetic knockdown or pharmacological inhibition of the P2RY12 receptor inhibited this effect in VSMCs. Phosphoproteomic analysis showed that the P2RY12 receptor regulated the autophagy pathway in VSMCs. Additionally, activation of the P2RY12 receptor inhibited MAP1LC3/LC3 maturation, SQSTM1 degradation, and autophagosome formation in VSMCs. Genetic knockdown of the essential autophagy gene Atg5 significantly attenuated P2RY12 receptor inhibitor-induced cholesterol efflux in VSMCs. Furthermore, activation of the P2RY12 receptor led to the activation of MTOR through PI3K-AKT in VSMCs, whereas blocking MTOR activity (rapamycin) or reducing MTOR expression reversed the inhibition of cholesterol efflux mediated by the P2RY12 receptor in VSMCs. In vivo, inhibition of the P2RY12 receptor promoted autophagy of VSMCs through PI3K-AKT-MTOR in advanced atherosclerosis in apoe-/- mice, which could be impeded by an autophagy inhibitor (chloroquine). Therefore, we conclude that activation of the P2RY12 receptor decreases cholesterol efflux and promotes VSMC-derived foam cell formation by blocking autophagy in advanced atherosclerosis. Our study thus suggests that the P2RY12 receptor is a therapeutic target for treating atherosclerosis. Abbreviations: 2-MeSAMP: 2-methylthioadenosine 5′-monophosphate; 8-CPT-cAMP: 8-(4-chlorophenylthio)-adenosine-3ʹ,5ʹ-cyclic-monophosphate; ABCA1: ATP binding cassette subfamily A member 1; ABCG1: ATP binding cassette subfamily G member 1; ACTB: actin beta; ADPβs: adenosine 5′-(alpha, beta-methylene) diphosphate; ALs: autolysosomes; AMPK: AMP-activated protein kinase; APOA1: apolipoprotein A1; APs: autophagosomes; ATG5: autophagy related 5; ATV: atorvastatin; AVs: autophagic vacuoles; CD: chow diet; CDL: clopidogrel; CQ: chloroquine; DAPI: 4ʹ,6-diamidino-2-phenylindole; dbcAMP: dibutyryl-cAMP; DIL-oxLDL: dioctadecyl-3,3,3,3-tetramethylin docarbocyanine-oxLDL; EIF4EBP1/4E-BP1: eukaryotic translation initiation factor 4E binding protein 1; EVG: elastic van gieson; HE: hematoxylin-eosin; HDL: high-density lipoprotein; HFD: high-fat diet; KEGG: Kyoto Encyclopedia of Genes and Genomes; LDL-c: low-density lipoprotein cholesterol; LDs: lipid droplets; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; Masson: masson trichrome; MCPT: maximal carotid plaque thickness; MK2206: MK-2206 2HCL; NBD-cholesterol: 22-(N-[7-nitrobenz-2-oxa-1,3-diazol-4-yl] amino)-23,24-bisnor-5-cholen-3β-ol; OLR1/LOX-1: oxidized low density lipoprotein receptor 1; ORO: oil Red O; ox-LDL: oxidized low-density lipoprotein; SQSTM1/p62: sequestosome 1; TEM: transmission electron microscopy; TIC: ticagrelor; ULK1: unc-51 like autophagy activating kinase 1; VSMCs: vascular smooth muscle cells [ABSTRACT FROM AUTHOR]