Identification of Lydicamycins as Main Antioomycete Compounds from the Biocontrol Agent Streptomyces sp. NEAU-S7GS2.

Oomycetes are well-known phytopathogens that seriously threaten many important crops worldwide. In this study, the endophytic actinobacterium Streptomyces sp. NEAU-S7GS2 demonstrated significant antagonistic activity against Phytophthora and Pythium and showed a potent biocontrol effect on suppression of soybean phytophthora root rot and pepper phytophthora blight. Two compounds were subsequently isolated as the main active components by bioassay-guided fractionation and identified as lydicamycins A and B. These two compounds showed high antioomycete activity against Phytophthora and Pythium with EC50 values of 0.73-2.67 µg/mL, which are equal to or lower than those of commercialized drug metalaxyl. In vivo bioassay using detached leaves demonstrated that lydicamycin A had a better control efficiency against soybean phytophthora root rot than metalaxyl. Taken together, these results suggest that the biocontrol agent Streptomyces sp. NEAU-S7GS2 and lydicamycins have the potential to be developed as promising pesticides to control diseases caused by oomycetes.

Phenopyrrolizins A and B, Two Novel Pyrrolizine Alkaloids from Marine-Derived Actinomycetes Micromonospora sp. HU138.

Two previously undescribed pyrrolizine alkaloids, named phenopyrrolizins A and B (1 and 2), were obtained from the fermentation broth of marine-derived Micromonospora sp. HU138. Their structures were established by extensive spectroscopic analysis, including 1D and 2D NMR spectra as well as HRESIMS data. The structure of 1 was confirmed by single-crystal diffraction analysis and its racemization mechanism was proposed. The antifungal activity assay showed that 2 could inhibit the mycelial growth of Botrytis cinerea with the inhibitory rates of 18.9% and 35.9% at 20 µg/disc and 40 µg/disc, respectively.

Asymptomatic COVID-19 infection in late pregnancy indicated no vertical transmission.

This study is to investigate the clinical characteristics of late pregnancy with asymptomatic 2019 novel coronavirus disease (COVID-19) infection, evaluate the outcome of maternal and fetal prognosis, and identify the evidence of intrauterine vertical transmission. A 22-years-old pregnant woman with asymptomatic COVID-19 infection who was admitted to our hospital on 11 February 2020 was enrolled in this study. Clinical data including laboratory test results and chest computed tomography (CT) scanning were collected and reviewed. Diagnosis of late pregnancy with asymptomatic COVID-19 infection was made. Lumbar anesthesia for cesarean section was performed and a female baby was delivered uneventfully, with the Apgar score of 9 to 10 points. Three times of COVID-19 nucleic acid test for the baby was negative after delivery. The puerpera returned to normal after the operation and two times of throat swab COVID-19 nucleic acid test were all negative after antiviral therapy. We reported an asymptomatic COVID-19 pregnant woman with detailed clinical information and our result indicated that for late pregnant women with asymptomatic COVID-19 infection, there might be no intrauterine infection caused by vertical transmission.

Mifepristone inhibits proliferation, migration and invasion of HUUA cells and promotes its apoptosis by regulation of FAK and PI3K/AKT signaling pathway.

PURPOSE: The aim was to investigate mifepristone effects on endometrial carcinoma and the related mechanism. METHODS: HHUA cells were treated with DMEM containing different concentrations of mifepristone. HHUA cells treated with 100 µmol/L mifepristone were named the Mifepristone group. HHUA cells co-transfected with pcDNA3.1-PI3K and pcDNA3.1-AKT overexpression vectors were treated with 100 µmol/L mifepristone and named the Mifepristone + PI3K/AKT group. mRNA expression was detected by quantitative reverse transcription PCR. Protein expression was performed by Western blot. Cell proliferation was conducted by MTT assay. Wound-healing assay was conducted. Transwell was used to detect cells migration and invasion. Apoptosis detection was performed by flow cytometry. RESULTS: Mifepristone inhibited HHUA cells proliferation in a dose-dependent manner. Compared with HHUA cells treated with 0 µmol/L mifepristone, HHUA cells treated by 50-100 µmol/L mifepristone had a lower wound-healing rate, a greater number of migrating and invasive cells (P<0.01), as well as a higher percentage of apoptotic cells and Caspase-3 expression (P<0.01). When HHUA cells were treated with 50-100 µmol/L of mifepristone, FAK, p-FAK, p-PI3K and p-AKT relative expression was all significantly lower than HHUA cells treated with 0 µmol/L of mifepristone (P<0.01). Compared with the Mifepristone group, HHUA cells of the Mifepristone + PI3K/AKT group had a lower cell growth inhibition rate and percentage of apoptotic cells (P<0.01). CONCLUSION: Mifepristone inhibited HUUA cells proliferation, migration and invasion and promoted its apoptosis by regulation of FAK and PI3K/AKT signaling pathway.

Long noncoding RNA LINC00261 regulates endometrial carcinoma progression by modulating miRNA/FOXO1 expression.

Long noncoding RNA LINC00261 was reported to be downregulated in multiple cancers. LINC00261 overexpression inhibits cancer cell proliferation, migration, and invasion. But the expression and function of LIN00261 in endometrial carcinoma are still elusive. We found that LINC00261 mRNA levels were downregulated in endometrial carcinoma, and LINC00261 overexpression inhibited endometrial carcinoma cell proliferation, migration, and invasion. miRNAs, including miR-182, miR-183, miR-153, miR-27a, and miR-96, were predicted to bind LINC00261 and FOXO1, and functioned to attenuate expression of LINC00261 and FOXO1. Overexpressed LINC00261 lowered these dissociative miRNAs, resulting in increase of FOXO1 protein levels. The knockdown of FOXO1 eliminated the suppression effect of overexpressed LINC00261 on endometrial carcinoma cell aggressiveness. LINC00261 promotes FOXO1 expression through reducing FOXO1-targeted miRNAs to suppress endometrial carcinoma cell proliferation, migration, and invasion. SIGNIFICANCE OF THE STUDY: LINC00261 is downregulated in endometrial carcinoma and associated with metastasis of this cancer. LINC00261 elevates FOXO1 protein levels through reducing FOXO1-targeted miRNAs to suppress endometrial carcinoma cell proliferation, migration, and invasion.