Altered N6-Methyladenosine Modification Patterns and Transcript Profiles Contributes to Cognitive Dysfunction in High-Fat Induced Diabetic Mice.

N6-methyladenosine (m6A) constitutes the paramount post-transcriptional modification within eukaryotic mRNA. This modification is subjected to stimulus-dependent regulation within the central nervous system of mammals, being influenced by sensory experiences, learning processes, and injuries. The patterns of m6A methylation within the hippocampal region of diabetes cognitive impairment (DCI) has not been investigated. A DCI model was established by feeding a high-fat diet to C57BL/6J mice. m6A and RNA sequencing was conducted to profile the m6A-tagged transcripts in the hippocampus. Methylated RNA immunoprecipitation with next-generation sequencing and RNA sequencing analyses yielded differentially m6A-modified and expressed genes in the hippocampus of DCI mice, which were enriched in pathways involving synaptic transmission and axonal guidance. Mechanistic analyses revealed a remarkable change in m6A modification levels through alteration of the mRNA expression of m6A methyltransferases (METTL3 and METTL14) and demethylase (FTO) in the hippocampus of DCI mice. We identified a co-mediated specific RNA regulatory strategy that broadens the epigenetic regulatory mechanism of RNA-induced neurodegenerative disorders associated with metabolic and endocrine diseases.

Effects of fatigue, rumination thinking, and sleep quality on hopelessness in family caregivers of cancer patients.

BACKGROUND: The heavy care burden, long-term dependence of caring for cancer patients, and changing social roles put family caregivers at high risk of mental disorders and hopelessness. This explored the relationship between fatigue, sleep quality, rumination, and hopelessness, and provides suggestions to maintain caregivers' mental health. METHODS: We investigated 536 family caregivers of cancer patients in three grade A hospitals in Liaoning Province who met the inclusion criteria on the Beck Hopelessness Scale (BHS), Fatigue Scale-14 (FS-14), Nolen-Hoeksema Ruminative Responses Scale (RRS), and Pittsburgh Sleep Quality Index (PSQI). Data were analyzed with SPSS 26.0, and Amos 22.0 was used to fit the structural equation model. RESULTS: The family caregivers had a higher degree of hopelessness and fatigue, while sleep quality and rumination were positively correlated with hopelessness (r = 0.483-0.906; P < 0.05). Fatigue and sleep quality can indirectly affect hopelessness through rumination thinking, while hopelessness has a direct effect on sleep. CONCLUSIONS: There are multiple action paths between fatigue and sleep quality, rumination thinking, and hopelessness. Family caregivers' physical and mental health can be maintained and hopelessness avoided by improving sleep quality, alleviating fatigue, and psychological counseling.

"It's a Tall Order but I'll Try": a qualitative study on Chinese nurses' cognition and experience responding to cancer patients' requests to hasten death.

PURPOSE: The purpose of this study is to understand the cognition and experience of oncology nurses in China when responding to a patient's request to hasten death, to describe the obstacles that prevent their response, and to provide suggestions for dealing with the patient's request. METHODS: Researchers conducted a qualitative study that consisted of open-ended, semi-structured interviews with 18 registered nurses who had more than 5 years of working experience in the oncology department at a large-scale urban hospital. We analyzed these data for content and themes. RESULTS: How to deal with patients' requests to hasten death is a problem often encountered and handled by nurses in the Department of Oncology. Nurses have a certain understanding of the patients' requests to hasten death. This study abstracts four themes: (1) the nurses' cognition of the "Accelerate the process of death"; (2) the methods they use to deal with the patients' requests to hasten death; (3) the obstacles that prevent nurses from fulfilling the patients' requests to hasten death; and (4) their suggestions for improvement. CONCLUSION: Nurses have a deep understanding of the real thoughts of patients who make a death request, and they hope to provide the corresponding psychological support and physical care. However, the lack of relevant knowledge, policy support, and cooperation of patients' families are obstacles that prevent them from taking action. Therefore, increasing relevant training for nurses, encouraging multi-department cooperation, and developing standardized nursing processes may lay a foundation for oncology nurses to better undertake and guide such conversations.

Solvothermal Synthesis of Novel Magnetic Nickel Based Iron Oxide Nanocomposites for Selective Capture of Global- and Mono-Phosphopeptides.

A facile solvothermal method was developed for synthesis of magnetic nickel-based iron oxide nanocomposites (MNFOs) with different ratios of Ni2+ to Fe3+ for different reaction time. Two factors including dosage of Ni source and length of reaction were investigated for influence on the morphology and composition of MNFOs, as well as their distinct selectivity for different phosphopeptides. After thorough characterization, the possible formation mechanism of MNFOs was proposed. Very interestingly, MNFOs with Ni2+/Fe3+ ratios of 4:5 prepared for 8 h (MNFO-S) and for 24 h (MNFO-L) can selectively capture global- and monophosphopeptides at the fmol level with excellent enrichment performance. These two affinity probes have been exploited to isolate and enrich the phosphopeptides from human normal hepatic cells HL 7702 after exposure to atmospheric fine particulates (PM2.1), which revealed that the protein phosphorylation level was increased significantly in cells after stimulation by fine particulate matters. The findings could provide a new insight for the nickel-based affinity protocol to analyze the mutation of phosphopeptides during cellular signaling pathways in response to exogenous environment stimulation. Consequently, this present work proposed a promising strategy to isolate monophosphopeptides from global phosphopeptides for phosphoproteome research.

Cytotoxicity and toxicoproteomic analyses of human lung epithelial cells exposed to extracts of atmospheric particulate matters on PTFE filters using acetone and water.

Differences of cytotoxicity associated with exposure to different extracts of atmospheric particulate matters (PMs) are still not well characterized by in vitro toxicoproteomics. In this study, in vitro cytotoxicity assays and toxicoproteomic analyses were carried out to investigate toxic effects of PM collected using polytetrafluoroethylene (PTFE) filters extracted with acetone for PM2.1 and water for PM2.1 and PM10 on A549 human lung epithelial cells. The cytotoxicity assays based on cell viability, cell apoptosis and reactive oxygen species generation indicated that PM2.1 extracted with acetone had the highest toxicity. iTRAQ labeling and LC-MS/MS analyses indicated that the number of differentially expressed proteins in A549 cells affected by PM2.1 extracted with acetone was noticeably higher than that of the other two groups. Hierarchical cluster analyses showed that the influences of the extracts of PM2.1 and PM10 using water on the proteome of A549 cells were similar, whereas significantly different from the effect of PM2.1 extracted with acetone. Pathways analyses indicated that PM2.1 extracted with acetone influenced the expression of proteins involved in 14 pathways including glycolysis/gluconeogenesis, pentose phosphate pathway, proteasome, etc. PM2.1 extracted with water affected the expression of proteins involved in 3 pathways including non-homologous end-joining, ribosome and endocytosis. However, PM10 extracted with water affected the expression of proteins involved in only spliceosome pathway. The extracts of PM using different extractants to detach PM from PTFE filters influenced the cytotoxic effects of PM and the proteome of A549 cells. Therefore, extractants should be assessed carefully before the investigations on cytotoxicity to improve the compatibility of experimental results among research teams.

Retention of nucleic acids in ion-pair reversed-phase high-performance liquid chromatography depends not only on base composition but also on base sequence.

The study on nucleic acid retention in ion-pair reversed-phase high-performance liquid chromatography mainly focuses on size-dependence, however, other factors influencing retention behaviors have not been comprehensively clarified up to date. In this present work, the retention behaviors of oligonucleotides and double-stranded DNAs were investigated on silica-based C18 stationary phase by ion-pair reversed-phase high-performance liquid chromatography. It is found that the retention of oligonucleotides was influenced by base composition and base sequence as well as size, and oligonucleotides prone to self-dimerization have weaker retention than those not prone to self-dimerization but with the same base composition. However, homo-oligonucleotides are suitable for the size-dependent separation as a special case of oligonucleotides. For double-stranded DNAs, the retention is also influenced by base composition and base sequence, as well as size. This may be attributed to the interaction of exposed bases in major or minor grooves with the hydrophobic alky chains of stationary phase. In addition, no specific influence of guanine and cytosine content was confirmed on retention of double-stranded DNAs. Notably, the space effect resulted from the stereostructure of nucleic acids also influences the retention behavior in ion-pair reversed-phase high-performance liquid chromatography.

A novel particulate matter sampling and cell exposure strategy based on agar membrane for cytotoxicity study.

Laboratories use different strategies to sample and extract atmospheric particulate matter (PM), some of which can be very complicated. Due to the absence of a standard protocol, it is difficult to compare the results of PM toxicity assessment across different laboratories. Here, we proposed a novel PM sampling and cell exposure strategy based on agar membrane. The agar membrane, prepared by a simple freeze-drying method, has a relatively flat surface and porous interior. We demonstrated that the agar membrane was a reliable substitute material for PM sampling. Then the PM on the agar membranes was directly extracted with the culture medium by vortex method, and the PM on the polytetrafluoroethylene (PTFE) filters was extracted with water by the traditional ultrasonic method for comparison. The extraction efficiency was evaluated and in vitro cytotoxicity assays were carried out to investigate the toxic effects of PM extracted with two strategies on macrophage cells. The results showed that the PM extracted from agar membranes induced higher cytotoxicity and more differentially expressed proteins. Overall, the novel PM sampling-cell exposure strategy based on the agar membrane is easy to operate, biocompatible and comparable, and has low disturbance, could be an alternative sampling and extraction method for PM toxicity assessment.

Aggregation and dissolution of engineering nano Ag and ZnO pretreated with natural organic matters in the simulated lung biological fluids.

The increasing application of engineered nanoparticles such as silver nanoparticles (nAg) and zinc oxide nanoparticles (nZnO), results in their accumulation in environmental media. The environmental natural organic matter (NOM) adsorbed by these nanoparticles may have great effects on the aggregation and dissolution of metall ions, which are interesting and important for the assessment of the inhalation risks of these airborne suspended NOM-coated nanoparticles to humans. Therefore, the aggregation and dissolution of nAg and nZnO pretreated with citric acid (CA), tartaric acid (TA) and fulvic acid (FA) in simulated lung biological fluids (artificial lysosomal fluid (ALF) and Gamble Solution) were investigated. The surface properties, morphology and size of the NOM-treated ENPs changed, but the crystalline phase was relatively stable when observed using surface-enhanced Raman scattering, transmission electron microscope, and X-ray diffraction. NOM treatment had no significant influence on the particle size of NOM-treated nAg and nZnO except for a decrease in the size of CA-treated nAg, and it could not promote the aggregation of NOM-treated nAg and nZnO except for the aggregation of TA-treated nAg in Gamble Solution or TA-treated nZnO in ALF. CA- and FA-treatments promoted the release of Zn2+ and Ag+, respectively, while no promotion was observed after TA-treatment. Therefore, NOM affects the release of Zn2+ and Ag+ from NOM-treated nAg and nZnO but does not promote the aggregation of NOM-treated nAg and nZnO, which influences the inhalation risk-based assessment.

Monolithic alkylsilane column: A promising separation medium for oligonucleotides by ion-pair reversed-phase liquid chromatography.

In this paper, a monolithic octadecylsilane column and particle-packed octadecylsilane columns were used to investigate the retention behaviors of oligonucleotides by ion-pair reversed-phase liquid chromatography (IP-RPLC). Results showed that, with same base composition, hairpin oligonucleotides always had weaker retention than corresponding random coil oligonucleotides on the monolithic column, but not on the particle-packed columns. In addition, the linear correlation between the retention factor k of oligonucleotides and the reciprocal of temperature (1/T), especially for hairpins, was relatively weaker on the particle-packed columns, as compared to the correlation on the monolithic column. The correlation between k and 1/T became weaker with decreasing particle size of the particle-packed columns. Moreover, results revealed that the overall retention order on the particle-packed column with small particles (3 µm) differed greatly from that on the monolithic column. In contrast, the retention order on the 10 µm particle-packed column was very close to that on the monolithic column. From the above, we inferred that oligonucleotides could keep their primary conformations unchanged when passing through the monolithic column, attributed to the special pore structures of the monolith. However, the conformations of oligonucleotides were suppressed or even destroyed when oligonucleotides passed through the particle-packed columns. This because the narrow and tortuous channels created by the stacked stationary phase particles could lead to more complex and unequable retention behaviors. Therefore, the monolithic column exhibited better retention regularity for oligonucleotides of secondary structure especially for hairpins than the particle-packed columns. It is noteworthy that the monolith-based IP-RPLC opens an intriguing prospect in accurately elucidating the retention behaviors of oligonucleotides.

Study on the polymorphism of G-quadruplexes by reversed-phase HPLC and LC-MS.

Polymorphism is inherent for G-quadruplexes (G4s), and the different structural forms are important for the participation in different biological functions of telomeres. A lot of progress has been made in the exploration of G4 polymorphism. However, quick separation and reliable assessment methods for different conformations of G4 are still very few. In this work, the polymorphism of three sequences d[(G3T)3G3], d[(G3C)3G3] and d[(G3T)4] annealed in six different solutions were investigated by means of reversed-phase high performance liquid chromatography (RP-HPLC), liquid chromatography-mass spectrometry (LC-MS), fluorescence spectroscopy, circular dichroism spectroscopy, together with native-polyacrylamide gel electrophoresis. Different G4 conformations of these three sequences can be separated clearly by RP-HPLC, and further characterized by on-line LC-MS analysis. It is revealed that high-order structures other than intramolecular quadruplexes were favored for d[(G3T)3G3] and d[(G3C)3G3] under the annealing conditions. However, flanking loop impeded d[(G3T)4] to form higher-order structures than dimer. In addition, the nature and concentration of cation, as well as the annealing solution component, all have decent influence on the stability and relative ratios of various G4 building blocks. Based on the above findings, RP-HPLC and LC-MS combined with spectroscopic techniques can be used as a facile and powerful tool for quick separation and identification of G4s in solutions, and for effective assessment of DNA sequences and annealing environments on G4 polymorphism. The established protocol provides a novel strategy for evaluating G4 polymorphism, which will facilitate studies on quadruplex structures and their biophysical properties.

FOXJ2 expression in rat spinal cord after injury and its role in inflammation.

Foxj2 (forkhead box J2), a novel member of the forkhead/HNF3 family, binds DNA with a dual sequence specificity. It may play a role in maintenance and survival of developing and adult neurons. However, its expression and function in the central nervous system lesion are still unclear. In this study, we performed a spinal cord injury (SCI) model in adult Sprague-Dawley rats and investigated the dynamic changes of Foxj2 expression in the spinal cord. Western blot analysis revealed that Foxj2 was present in normal spinal cord. It gradually increased, reached a peak at day 5 after SCI, and then declined during the following days. Double immunofluorescence staining revealed wide expression of Foxj2, which is detected in neurons and astrocytes. After injury, Foxj2 expression was increased predominantly in astrocytes, which highly expressed proliferating cell nuclear antigen, a marker for proliferating cells. And knockdown of Foxj2 in cultured primary astrocytes by siRNA showed that Foxj2 played an important role in lipopolysaccharide-induced inflammatory responses. These results suggested that Foxj2 may be involved in the pathophysiology of SCI, and further research is needed to have a good understanding of its function and mechanism.