Azadirachtin Inhibits Nuclear Receptor HR3 in the Prothoracic Gland to Block Larval Ecdysis in the Fall Armyworm, Spodoptera frugiperda.

Azadirachtin has been used to control agricultural pests for a long time; however, the molecular mechanism of azadirachtin on lepidopterans is still not clear. In this study, the fourth instar larvae of fall armyworm were fed with azadirachtin, and then the ecdysis was blocked in the fourth instar larval stage (L4). The prothoracic glands (PGs) of the treated larvae were dissected for RNA sequencing to determine the effect of azadirachtin on ecdysis inhibition. Interestingly, one of the PG-enriched genes, the nuclear hormone receptor 3 (HR3), was decreased after azadirachtin treatment, which plays a critical role in the 20-hydroxyecdysone action during ecdysis. To deepen the understanding of azadirachtin on ecdysis, the HR3 was knocked out by using the CRISPR/Cas9 system, while the HR3 mutants displayed embryonic lethal phenotype; thus, the stage-specific function of HR3 during larval molting was not enabled to unfold. Hence, the siRNA was injected into the 24 h L4 larvae to knock down HR3. After 96 h, the injected larvae were blocked in the old cuticle during ecdysis which is consistent with the azadirachtin-treated larvae. Taken together, we envisioned that the inhibition of ecdysis in the fall armyworm after the azadirachtin treatment is due to an interference with the expression of HR3 in PG, resulting in larval mortality. The results in this study specified the understanding of azadirachtin on insect ecdysis and the function of HR3 in lepidopteran in vivo.

Research progress on the relationship between Porphyromonas gingivalis and the malignancy of the digestive system and possible pathogenetic mechanism / 华西口腔医学杂志

The malignant tumors including oral cancer, colorectal cancer, pancreatic cancer, and esophageal cancer, of the digestive system are a common high-fatal malignancy. Porphyromonas gingivalis, as the most important pathogen of periodontal disease, has been gradually proved that its invasiveness occurs not only in the mouth but also in other parts of the digestive system. Moreover, the relevant pathogenic mechanism is increasingly attracting the reseachers' attention. In this study, the role and possible pathogenesis of Porphyromonas gingivalis in the digestive system are described in a systematic and comprehensive way.

The effect of the expression of matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 protein on the window phase of endometrial implantation in unexplained infertillie women / 浙江大学学报·医学版

OBJECTIVE: To explore the role of matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinase-1 ( TIMP-1) protein on embryo implantation in unexplained infertile women. METHODS: Forty three women were divided into two groups: 29 unexplained infertile (study group) and 14 women with normal fertile function (control group).Immunohistochemical analysis was applied to measure the cell expression of MMP-9 and TIMP-1 in the endometrial implantation window phase of the two groups. RESULTS: The cells positive for these solu-ble proteinases were found in the epithelial and stromal cells in all endometrial samples. Semi-quantitative analysis showed that,MMP-9 and TIMP-1 were weaker in the endometrial glandular cells of infertile women then in those of the control group(MMP-9:230.79+/-43.92 compared with 307.78+/-44.25; TIMP-1:233.05+/-48.51 compared with 297.86+/-35.56,P<0.05). There was no statistical correlation between MMP-9 and TIMP-1 with blood estradiol(E(2)) and progesterone (P) in the two groups (P>0.05). But in control group, there was a negative correlation tendency in MMP-9/P and TIMP-1/P (MMP-9/P: r=-0.330,TIMP-1/P: r=-0.401). CONCLUSION: In unexplained inferrile women, the low expression of MMP-9 and TIMP-1 protein in the implantation window phase may be one of the important factors that affect the embryo impantation.