Corrigendum: The m6A-methylated mRNA pattern and the activation of the Wnt signaling pathway under the hyper-m6A-modifying condition in the keloid.

[This corrects the article DOI: 10.3389/fcell.2022.947337.].

The m6A-methylated mRNA pattern and the activation of the Wnt signaling pathway under the hyper-m6A-modifying condition in the keloid.

Purpose: The present study was carried out to investigate the global m6A-modified RNA pattern and possible mechanisms underlying the pathogenesis of keloid. Method: In total, 14 normal skin and 14 keloid tissue samples were first collected on clinics. Then, three samples from each group were randomly selected to be verified with the Western blotting to determine the level of methyltransferase and demethylase. The total RNA of all samples in each group was isolated and subjected to the analysis of MeRIP sequencing and RNA sequencing. Using software of MeTDiff and htseq-count, the m6A peaks and differentially expressed genes (DEGs) were determined within the fold change >2 and p-value < 0.05. The top 10 pathways of m6A-modified genes in each group and the differentially expressed genes were enriched by the Kyoto Encyclopedia of Genes and Genomes signaling pathways. Finally, the closely associated pathway was determined using the Western blotting and immunofluorescence staining. Results: There was a higher protein level of WTAP and Mettl3 in the keloid than in the normal tissue. In the keloid samples, 21,020 unique m6A peaks with 6,573 unique m6A-associated genetic transcripts appeared. In the normal tissue, 4,028 unique m6A peaks with 779 m6A-associated modified genes appeared. In the RNA sequencing, there were 847 genes significantly changed between these groups, transcriptionally. The genes with m6A-methylated modification and the upregulated differentially expressed genes between two tissues were both mainly related to the Wnt signaling pathway. Moreover, the hyper-m6A-modified Wnt/ß-catenin pathway in keloid was verified with Western blotting. From the immunofluorescence staining results, we found that the accumulated fibroblasts were under a hyper-m6A condition in the keloid, and the Wnt/ß-Catenin signaling pathway was mainly activated in the fibroblasts. Conclusion: The fibroblasts in the keloid were under a cellular hyper-m6A-methylated condition, and the hyper-m6A-modified highly expressed Wnt/ß-catenin pathway in the dermal fibroblasts might promote the pathogenesis of keloid.

Identification of a potential diagnostic signature for postmenopausal osteoporosis via transcriptome analysis.

Purpose: We aimed to establish the transcriptome diagnostic signature of postmenopausal osteoporosis (PMOP) to identify diagnostic biomarkers and score patient risk to prevent and treat PMOP. Methods: Peripheral blood mononuclear cell (PBMC) expression data from PMOP patients were retrieved from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) were screened using the "limma" package. The "WGCNA" package was used for a weighted gene co-expression network analysis to identify the gene modules associated with bone mineral density (BMD). Least absolute shrinkage and selection operator (LASSO) regression was used to construct a diagnostic signature, and its predictive ability was verified in the discovery cohort. The diagnostic values of potential biomarkers were evaluated by receiver operating characteristic curve (ROC) and coefficient analysis. Network pharmacology was used to predict the candidate therapeutic molecules. PBMCs from 14 postmenopausal women with normal BMD and 14 with low BMD were collected, and RNA was extracted for RT-qPCR validation. Results: We screened 2420 differentially expressed genes (DEGs) from the pilot cohort, and WGCNA showed that the blue module was most closely related to BMD. Based on the genes in the blue module, we constructed a diagnostic signature with 15 genes, and its ability to predict the risk of osteoporosis was verified in the discovery cohort. RT-qPCR verified the expression of potential biomarkers and showed a strong correlation with BMD. The functional annotation results of the DEGs showed that the diagnostic signature might affect the occurrence and development of PMOP through multiple biological pathways. In addition, 5 candidate molecules related to diagnostic signatures were screened out. Conclusion: Our diagnostic signature can effectively predict the risk of PMOP, with potential application for clinical decisions and drug candidate selection.

Self-compassion and resilience mediate the relationship between childhood exposure to domestic violence and posttraumatic growth/stress disorder during COVID-19 pandemic.

BACKGROUND: Studies have indicated that childhood exposure to domestic violence is a common factor in posttraumatic growth (PTG) and posttraumatic stress disorder (PTSD), but it is unclear whether PTG and PTSD share a common/different underlying mechanism. AIM: To explore the common/different underlying mechanism of PTG and PTSD. METHODS: Between February 12 and 17, 2020, a nationwide cross-sectional online survey was conducted in China among 2038 university students, and a self-administered questionnaire was used for the data collection. The data included demographic characteristics, such as age, gender, and subjective social economic status, and childhood exposure to domestic violence scale that was selected from the Chinese version of revised Adverse Childhood Experiences Question, Self-compassion Scale, Connor-Davidson Resilience Scale, Posttraumatic Growth Inventory, and the Abbreviated PTSD Checklist-Civilian version. A structural equation model was used to test the hypotheses. RESULTS: Exposure to domestic violence was significantly associated with PTG and PTSD via a 1-step indirect path of self-compassion (PTG: ß = -0.023, 95%CI: -0.44 to -0.007; PTSD: ß = 0.008, 95%CI: 0.002, 0.014) and via a 2-step indirect path from self-compassion to resilience (PTG: ß = -0.008, 95%CI: -0.018 to -0.002; PTSD: ß = 0.013, 95%CI: 0.004-0.024). However, resilience did not mediate the relationship between exposure to domestic violence and PTG and PTSD. CONCLUSION: PTG and PTSD are common results of childhood exposure to domestic violence, which may be influenced by self-compassion and resilience.

Plasma pharmacokinetics and cerebral nuclei distribution of major constituents of Psoraleae fructus in rats after oral administration.

BACKGROUND: The fruit of Psoralea corylifolia L., Psoraleae fructus (PF), is widely used in traditional Chinese medicine as a well-known herbal tonic. Previous studies have shown that PF and its major constituents may have potential values in the treatment of Parkinson and Alzheimer diseases, though their pharmacokinetics and brain distribution were largely unknown. PURPOSE: To develop a liquid chromatographic-tandem mass spectrometry (LC-MS/MS) method for simultaneous studies of the plasma pharmacokinetics and cerebral nuclei (including cerebellum, thalamus, brainstem, hippocampus, corpus striatum and cortex) distribution in rats of eleven known PF compounds following as psoralen, isopsoralen, psoralidin, bavachin, bavachinin, isobavachin, isobavachalcone, bavachalcone, neobavaisoflavone, corylifol A, and corylin. METHODS: Rats were orally administered via gavage at a single dose of PF extract at 1.2 g/kg. The eleven known PF compounds were extracted from rat plasma and cerebral nuclei at different time points, and then determined by the established LC-MS/MS method. Non-compartmental pharmacokinetic profiles were calculated, and the distribution in rat plasma and cerebral nuclei were compared. RESULTS: The results showed that all the tested compounds were quickly absorbed into rat plasma and distributed almost evenly to the cerebral nuclei. The distribution concentrations at different nuclei varied at one determined time point, but the overall trends were basically similar to the plasma concentration-time results. Psoralen and isopsoralen, the two highest coumarins contained in PF, displayed far higher plasma concentrations (AUC0→∞, plasma≈53,884∼65,578 ng·h/ml) and central nervous system penetration (AUC0→∞, brain nuclei ≈44,659∼65,823 ng·h/g) than the prenylflavonoids (other compounds except psoralidin, AUC0→∞, plasma≈69∼324 ng·h/ml; AUC0→∞, brain nuclei ≈119∼3662 ng·h/g). However, the total brain-to-plasma ratios of the prenylflavonoids were higher than the coumarins, suggesting the prenylflavonoids can more readily enter the brain than the coumarins. CONCLUSION: The established LC-MS/MS method is sensitive and specific for the simultaneous quantitation of the eleven PF compounds in rat plasma and cerebral nuclei. The results of plasma pharmacokinetics and cerebral nuclei distribution may reveal the possible substance basis for the CNS activities of PF, and highlight the application possibility of PF and its major constituents in the treatment of Parkinson and Alzheimer diseases.

Dietary Total Prenylflavonoids from the Fruits of Psoralea corylifolia L. Prevents Age-Related Cognitive Deficits and Down-Regulates Alzheimer's Markers in SAMP8 Mice.

Alzheimer's disease (AD) is a serious threat for the aging society. In this study, we examined the preventive effect of the total prenylflavonoids (TPFB) prepared from the dried fruits of Psoralea corylifolia L., using an age-related AD mouse model SAMP8. We found that long-term dietary TPFB at 50 mg/kg·day significantly improved cognitive performance of the SAMP8 mice in Morris water maze tests, similar to 150 mg/kg·day of resveratrol, a popular neuro-protective compound. Furthermore, TPFB treatment showed significant improvements in various AD markers in SAMP8 brains, which were restored to near control levels of the normal mice, SAMR1. TPFB significantly reduced the level of amyloid ß-peptide 42 (Aß42), inhibited hyperphosphorylation of the microtubule-associated protein Tau, induced phosphorylation of Ser9 of the glycogen synthase kinase 3ß (GSK-3ß), and decreased the expression of the proinflammatory cytokines TNFα, IL-6, and IL-1ß. Finally, TPFB also markedly reduced the level of serum derivatives of reactive oxygen metabolites (d-ROMs), a biomarker of oxidative stress in vivo. These results showed that dietary TPFB could effectively prevent age-related cognitive deficits and AD-like neurobiochemical changes, and may have a potential role in the prevention of Alzheimer's disease.