Enhancer-driven transcription of MCM8 by E2F4 promotes ATR pathway activation and glioma stem cell characteristics.

BACKGROUND: Glioma stem cells (GSCs) are responsible for glioma recurrence and drug resistance, yet the mechanisms underlying their maintenance remains unclear. This study aimed to identify enhancer-controlled genes involved in GSCs maintenance and elucidate the mechanisms underlying their regulation. METHODS: We analyzed RNA-seq data and H3K27ac ChIP-seq data from GSE119776 to identify differentially expressed genes and enhancers, respectively. Gene Ontology analysis was performed for functional enrichment. Transcription factors were predicted using the Toolkit for Cistrome Data Browser. Prognostic analysis and gene expression correlation was conducted using the Chinese Glioma Genome Atlas (CGGA) data. Two GSC cell lines, GSC-A172 and GSC-U138MG, were isolated from A172 and U138MG cell lines. qRT-PCR was used to detect gene transcription levels. ChIP-qPCR was used to detect H3K27ac of enhancers, and binding of E2F4 to target gene enhancers. Western blot was used to analyze protein levels of p-ATR and γH2AX. Sphere formation, limiting dilution and cell growth assays were used to analyze GSCs growth and self-renewal. RESULTS: We found that upregulated genes in GSCs were associated with ataxia-telangiectasia-mutated-and-Rad3-related kinase (ATR) pathway activation, and that seven enhancer-controlled genes related to ATR pathway activation (LIN9, MCM8, CEP72, POLA1, DBF4, NDE1, and CDKN2C) were identified. Expression of these genes corresponded to poor prognosis in glioma patients. E2F4 was identified as a transcription factor that regulates enhancer-controlled genes related to the ATR pathway activation, with MCM8 having the highest hazard ratio among genes positively correlated with E2F4 expression. E2F4 bound to MCM8 enhancers to promote its transcription. Overexpression of MCM8 partially restored the inhibition of GSCs self-renewal, cell growth, and the ATR pathway activation caused by E2F4 knockdown. CONCLUSION: Our study demonstrated that E2F4-mediated enhancer activation of MCM8 promotes the ATR pathway activation and GSCs characteristics. These findings offer promising targets for the development of new therapies for gliomas.

The association between the romantic relationships of parents and offspring depressive symptoms: Mediating effects of offspring communication patterns and romantic relationships.

This study investigated a conceptual model by testing how parental romantic relationships influenced the depressive symptoms of grown-up children and whether the constructive communication patterns of grown-up children and romantic relationships played mediation effects within it. A total of 421 Chinese participants were enrolled in the study. The level of depressive symptoms, romantic relationship satisfaction and closeness, couple communication patterns, and parental romantic relationships were measured via self-report questionnaires. According to the results, the structural equation modeling analysis verified that the severity of participants' depressive symptoms was negatively associated with the parental romantic relationship and that the association was mediated by participants' constructive communication patterns and their own romantic relationships. Furthermore, compared with nondepressed participants, depressed participants were less satisfied with their parental romantic relationships, exhibited fewer constructive communication patterns, and were more distant and unsatisfied with current romantic relationships.

A novel bee-friendly peptidomimetic insecticide: Synthesis, aphicidal activity and 3D-QSAR study of insect kinin analogs at Phe2 modification.

BACKGROUND: As one of the most abundant and destructive pests in agriculture, aphids cause significant damage to crops due to their sap-taking and as virus vectors. Chemical insecticides are the most effective method to control aphids, but they bring insecticide resistance problems and harm nontarget organisms, especially bees, therefore the search for novel eco-friendly aphid control agents with low bee toxicity is urgent. Insect kinins are a class of small neuropeptides that control important functions in insects. In our previous study, we found insect kinin analog IV-3 has good aphicidal activity and the location of the aromatic ring on the side chain of Phe2 is the key to the formation of the ß-turn resulting in the biological activity of insect kinin analogs. However, there are few studies on insect kinin Phe2 substitution and modification, and its structure-activity relationship is still unclear. RESULTS: In this project, 44 insect kinin analogs with the Phe2 modification, replacing it with different natural or unnatural amino acids, were designed and synthesized based on the lead IV-3 to explore the role of the Phe2 residues. Bioassays with soybean aphids of Aphis glycines indicated that nine analogs have better aphicidal activity than the lead IV-3. In particular, compound L25 exhibits excellent aphicidal activity (LC50  = 0.0047 mmol L-1 ) and has low toxicity to bees. Furthermore, a reliable three-dimensional quantitative structure-activity relationship (3D-QSAR) was established to produce a helpful clue that introducing hydrophobic groups away from the backbone chain is beneficial to improve aphicidal activity. CONCLUSION: The residue Phe2 of insect kinin analogs is the key position and has a significant impact on the activity. L25 has a high toxicity for aphids, while a low toxicity to bees, and therefore can be considered as a lead compound to develop new biosafe aphid control agents. Finally, we provide a useful 3D-QSAR model as theoretical guidance for further structural optimization. © 2022 Society of Chemical Industry.

Melatonin inhibits ESCC tumor growth by mitigating the HDAC7/ß-catenin/c-Myc positive feedback loop and suppressing the USP10-maintained HDAC7 protein stability.

BACKGROUND: Melatonin, a natural hormone secreted by the pineal gland, has been reported to exhibit antitumor properties through diverse mechanisms of action. However, the oncostatic function of melatonin on esophageal squamous cell carcinoma (ESCC) remains elusive. This study was conducted to investigate the potential effect and underlying molecular mechanism of melatonin as single anticancer agent against ESCC cells. METHODS: ESCC cell lines treated with or without melatonin were used in this study. In vitro colony formation and EdU incorporation assays, and nude mice tumor xenograft model were used to confirm the proliferative capacities of ESCC cells. RNA-seq, qPCR, Western blotting, recombinant lentivirus-mediated target gene overexpression or knockdown, plasmids transfection and co-IP were applied to investigate the underlying molecular mechanism by which melatonin inhibited ESCC cell growth. IHC staining on ESCC tissue microarray and further survival analyses were performed to explore the relationship between target genes' expression and prognosis of ESCC. RESULTS: Melatonin treatment dose-dependently inhibited the proliferative ability and the expression of histone deacetylase 7 (HDAC7), c-Myc and ubiquitin-specific peptidase 10 (USP10) in ESCC cells (P < 0.05). The expressions of HDAC7, c-Myc and USP10 in tumors were detected significantly higher than the paired normal tissues from 148 ESCC patients (P < 0.001). Then, the Kaplan-Meier survival analyses suggested that ESCC patients with high HDAC7, c-Myc or USP10 levels predicted worse overall survival (Log-rank P < 0.001). Co-IP and Western blotting analyses further revealed that HDAC7 physically deacetylated and activated ß-catenin thus promoting downstream target c-Myc gene transcription. Notably, our mechanistic study validated that HDAC7/ß-catenin/c-Myc could form the positive feedback loop to enhance ESCC cell growth, and USP10 could deubiquitinate and stabilize HDAC7 protein in the ESCC cells. Additionally, we verified that inhibition of the HDAC7/ß-catenin/c-Myc axis and USP10/HDAC7 pathway mediated the anti-proliferative action of melatonin on ESCC cells. CONCLUSIONS: Our findings elucidate that melatonin mitigates the HDAC7/ß-catenin/c-Myc positive feedback loop and inhibits the USP10-maintained HDAC7 protein stability thus suppressing ESCC cell growth, and provides the reference for identifying biomarkers and therapeutic targets for ESCC.

Flame Retardancy of High-Density Polyethylene Composites with P,N-Doped Cellulose Fibrils.

To derive P,N-doped cellulose fibrils, phosphoric acid and aqueous ammonia were placed in a one-pot reaction, and the phosphate groups and ammonium phosphates were successfully introduced into the cellulose surface. The obtained P,N-doped cellulose fibrils with high liberation were thereafter incorporated into a high-density polyethylene (HDPE) matrix to improve the flame retardancy of HDPE composites, and they had a significant improvement on flame retardancy of HDPE composites. In particular, 7 wt % P,N-doped cellulose fibrils considerably reduced the average and peak heat release rate (HRR) by 29.6% and 72.9%, respectively, and increased the limited oxygen index (LOI) by 30.5%. The presence of phosphate groups and ammonium phosphates within P,N-doped cellulose fibrils was found to promote the thermal degradation of HDPE composites at a lower temperature (i.e., 240 °C). The released acid catalyzed the dehydration of cellulose to form an aromatic carbonaceous structure with a higher crystalline orientation, which improves the flame retardancy of HDPE composites.

[Effects of balance-acupuncture stimulation of "back pain" and "hip pain" points on plasma beta-endorphin and ACTH contents in rats with lumbar disc herniation].

OBJECTIVE: To observe the effect of balance acupuncture on the thermal pain threshold and plasma beta-endorphin (beta-EP) and adrenocorticotrophic hormone (ACTH) levels in lumbar disc herniation rats so as to research its mechanisms underlying improvement of lumbar disc protrusion. METHODS: A total of 120 male rats were randomly divided into blank control (control) group, model group, sham-operation(sham)group, and acupuncture group (n=30) which were further divided into 7-days (d) and 14-d subgroups. Rats in the acupuncture group were treated with balance acupuncture of "Back Pain" point (the midpoint between two eyes) and "Hip Pain"point (the midpoint between the acromial process and the axillary furrow). Thermal pain threshold was detected by using radiant heat detector. Plasma beta-EP and ACTH levels were determined by radioimmunoassay. RESULTS: Compared with the control group and pre-operation and sham group, the thermal pain reaction was increased significantly in the model group (P < 0.05). In comparison with the model group, the thermal pain reaction was decreased obviously from day 10 after acupuncture treatment in the acupuncture group (P < 0.05). Compared to the control group, plasma beta-EP contents on day 7 and 14 and ACTH level on day 14 in the model group were increased significantly (P < 0.05), while in comparison with the model group, plasma beta-EP contents on day 7 and 14 and ACTH level on day 14 in the acupuncture group were down-regulated markedly (P < 0.05). No significant difference were found between the control and sham groups in plasma beta-EP contents and ACTH levels on day 7 and 14 (P > 0.05). CONCLUSION: Balance acupuncture treatment can lower plasma ACTH level in lumbar disc herniation rats, which may contribute to its effect in easing lumbar disc herniation pain in clinic practice.