The First Lanthipeptide from Lactobacillus iners, Inecin L, Exerts High Antimicrobial Activity against Human Vaginal Pathogens.

Vaginal infections continue to be a serious public health issue, and developing new approaches to address antibiotic-resistant pathogens is an urgent task. The dominant vaginal Lactobacillus species and their active metabolites (e.g., bacteriocins) have the potential to defeat pathogens and help individuals recover from disorders. Here, we describe for the first time a novel lanthipeptide, inecin L, a bacteriocin from Lactobacillus iners with posttranslational modifications. The biosynthetic genes of inecin L were actively transcribed in the vaginal environment. Inecin L was active against the prevailing vaginal pathogens, such as Gardnerella vaginalis and Streptococcus agalactiae, at nanomolar concentrations. We demonstrated that the antibacterial activity of inecin L was closely related to the N terminus and the positively charged His13 residue. In addition, inecin L was a bactericidal lanthipeptide that showed little effect on the cytoplasmic membrane but inhibited the cell wall biosynthesis. Thus, the present work characterizes a new antimicrobial lanthipeptide from a predominant species of the human vaginal microbiota. IMPORTANCE The human vaginal microbiota plays essential roles in preventing pathogenic bacteria, fungi, and viruses from invading. The dominant vaginal Lactobacillus species show great potential to be developed as probiotics. However, the molecular mechanisms (such as bioactive molecules and their modes of action) involved in the probiotic properties remain to be determined. Our work describes the first lanthipeptide molecule from the dominant Lactobacillus iners. Additionally, inecin L is the only lanthipeptide found among the vaginal lactobacilli thus far. Inecin L shows strong antimicrobial activity toward the prevalent vaginal pathogens and antibiotic-resistant strains, suggesting that inecin L is a potent antibacterial molecule for drug development. In addition, our results show that inecin L exhibits specific antibacterial activity related to the residues in the N-terminal region and ring A, which will contribute to structure-activity relationship studies in lacticin 481-like lanthipeptides.

Histone deacetylase HDAC2 silencing prevents endometriosis by activating the HNF4A/ARID1A axis.

Endometriosis is the most major cause of chronic pelvic pain in women of reproductive age. Moreover, the involvement of histone deacetylase 2 (HDAC2) has been identified in endometriosis. However, the specific mechanism of HDAC2 remains to be further elusive. Therefore, this study was designed to explore the mechanism of HDAC2 orchestrating hepatocyte nuclear factor 4α/AT-rich interactive domain 1A (HNF4A/ARID1A) axis in endometriosis. Endometriosis cell line hEM15A and clinical endometriosis tissues were obtained, followed by gain- and loss-of-function assays in hEM15A cells. HDAC2, HNF4A and ARID1A expression was detected by immunohistochemistry and Western blot analysis. Cell viability was determined by Cell Counting Kit-8 Assay, invasion by Transwell assay and apoptosis by flow cytometry. HDAC2 enrichment in HNF4A promoter region and HNF4A enrichment in ARID1A promoter region was detected through chromatin immunoprecipitation. Mouse models of endometriosis were established, followed by immunohistochemistry of Ki-67 expression and TUNEL staining of apoptosis in ectopic tissues. HDAC2 was upregulated but HNF4A and ARID1A were downregulated in endometriosis tissues. HDAC2 inhibited HNF4A expression by deacetylation, and HNF4A was enriched in ARID1A promoter region to activate ARID1A. Silencing HDAC2 or overexpressing HNF4A or ARID1A diminished the viability and invasion and augmented the apoptosis of hEM15A cells. HDAC2 silencing reduced the area and weight of endometriosis tissues, suppressed endometriosis cell proliferation and accelerated endometriosis cell apoptosis. The inhibitory action of silencing HDAC2 via HNF4A/ARID1A axis was reproduced in mouse models. Collectively, HDAC2 silencing might upregulate HNF4A via repression of deacetylation to activate ARID1A, thus preventing the occurrence of endometriosis.

LINC01541 overexpression attenuates the 17ß-Estradiol-induced migration and invasion capabilities of endometrial stromal cells.

Endometriosis affects 6-10% of healthy women of reproductive age. Therefore, it is important to study the molecular mechanism by which endometriosis develops. This study examined whether aberrant expression of LINC01541 contributes to the pathogenesis of endometriosis. Human endometrial stromal cells (ESCs) were stimulated with 10 nmol/L of 17ß-Estradiol (17ß-E2) to simulate ectopic cells found in endometriosis. Next, the levels of proteins related to the epithelial-mesenchymal transition (EMT), cell invasion, and metastasis were investigated. The effects of LINCO1541 silencing and overexpression were also examined in ESCs. Cell proliferation and apoptosis were detected by cell counting kit-8 and flow cytometry assays, respectively. ESCs stimulated with 17ß-E2 displayed increased levels of N-Cadherin and vimentin expression, but decreased levels of E-Cadherin expression. 17ß-E2 promoted the migration and invasion of ESCs, and those affects were partially reversed by overexpression of LINC01541. Furthermore, silencing of LINC01541 attenuated apoptosis and promoted the EMT of ESCs, while overexpression of LINC01541 stimulated cell apoptosis, increased the levels of caspase 3 protein, and decreased the levels of B cell leukemia/lymphoma 2 protein. Overexpression of LINC01541 also decreased the expression of vascular endothelial growth factor A (VEGFA) by repressing the Wnt/ß-catenin pathway. Our, results suggest that LINC01541 can inhibit the EMT process, metastasis of ESCs, and VEGFA expression by regulating the Wnt/ß-catenin pathway, which may play an important role in the pathogenesis of endometriosis. Abbreviations: ESCs: endometrial stromal cells; 17ß-E2: 17ß-Estradiol; EMT: epithelial-mesenchymal transition; CASP3: caspase 3; BCL2: B cell leukemia/lymphoma 2; VEGFA: vascular endothelial growth factor A; lncRNA: long non-coding RNA; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; RT-qPCR: reverse transcription-quantitative polymerase chain reaction.

MiR-143-3p suppresses the progression of ovarian cancer.

MicroRNAs (miRNAs) are a class of naturally occurring, small, non-coding RNAs that target protein-coding mRNAs at the post-transcriptional level and participate in various biological processes. Our previous studies suggested that miR-143-3p functions as a tumor suppressor and has a role in the progression of ovarian cancer, in part through the regulation of the tumor promoter. In this study, we found that the mRNA expression level of miR-143-3p was significantly decreased in ovarian cancer tissues, in comparison with normal ovarian tissues by high-throughput miRNA profiling and quantitative RT-PCR. Secondly, we indicated that the up-regulation of miR-143-3p in the ovarian cancer cell lines SKOV3, ES2, and OVCAR3 significantly reduced their proliferation, migration, and invasion. Furthermore, miR-143-3p inhibited the growth of ovarian tumors in vivo in a xenograft experiment. In addition, miR-143-3p down-regulated the expression of transforming growth factor (TGF)-ß-activated kinase 1 (TAK1) in human ovarian cancer cells. Therefore, our study indicates that miR-143-3p inhibited the proliferation, migration, and invasion of ovarian cancer cells in vitro, as well as ovarian tumorigenesis in vivo. This inhibitory effect may target TAK1, suggesting a potential application of the miR-143-3p-TAK1 pathway in the clinical diagnosis and treatment of ovarian cancer.

[Corrigendum] miR-28-5p promotes the development and progression of ovarian cancer through inhibition of N4BP1.

Following the publication of this article, the authors noted that there was an error in the affiliations. Specifically, the affiliation of the first author JUAN XU should be: Jinhua Municipal Central Hospital, Jinhua Hospital of Zhejiang University, Jinhua, Zhejiang 321000, P.R. China. [the original article was published in the International Journal of Oncology 50: 1383-1391, 2017; DOI: 10.3892/ijo.2017.3915].

miR-28-5p promotes the development and progression of ovarian cancer through inhibition of N4BP1.

MicroRNAs (miRNAs) play important roles in transcriptional regulation by targeting the 3'-UTR of target genes which participate in various biological processes. We aimed to investigate the potential role of miR-28-5p in the process of ovarian cancer development through regulating N4BP1. We found that the mRNA expression level of miR-28-5p was significantly increased in ovarian cancer tissues in comparison with adjacent ovarian tissues by qRT-PCR (P<0.0001). We established that miR­28­5p promoted the progression of ovarian cancer cell proliferation using colony forming assay and MTT assay. Wound healing assay and the migration and invasion assay showed that miR­28­5p accelerated the migration and invasion abilities of ovarian cancer cells. Simultaneously, we showed that miR­28­5p promoted ovarian cancer cell cycle, and inhibited apoptosis by flow cytometry in vitro. Furthermore, the results showed that miR­28­5p promoted the growth of ovarian tumor by tumor formation assay in vivo. The results of western blot analysis indicated that miR­28­5p promoted the protein expression level of F-actin. Western blot analysis also demonstrated that miR­28­5p promoted the progress of epithelial-mesenchymal transition (EMT) in ovarian carcinoma cells. In addition, we found that miR­28­5p downregulated N4BP1 mRNA and protein expression by qRT-PCR and western blot analysis in human ovarian cancer. Therefore, our study indicated that miR­28­5p promoted the progression of ovarian cancer cell cycle, proliferation, migration and invasion, inhibited apoptosis, and induced the process of EMT through inhibition of N4BP1 in vitro. Moreover, miR­28­5p promoted the growth of ovarian tumor in vivo.

Structure-Guided Design of Novel, Potent, and Selective Macrocyclic Plasma Kallikrein Inhibitors.

A series of macrocyclic analogues were designed and synthesized based on the cocrystal structure of small molecule plasma kallikrein (pKal) inhibitor, 2, with the pKal protease domain. This led to the discovery of a potent macrocyclic pKal inhibitor 29, with an IC50 of 2 nM for one olefinic isomer and 42.3 nM for the other olefinic isomer.

ShRNA-mediated silencing of the RFC3 gene suppress ovarian tumor cells proliferation.

Ovarian carcinoma is one of the most common and lethal malignancies in the world. Replication factor C (RFC) plays an important role in DNA replication, DNA damage repair, and checkpoint control during cell cycle progression in all eukaryotes. Our previous study found that one unit of RFC complex, RFC3, is over-expressed in ovarian tumor tissues. However, its role in the development of ovarian carcinoma remains unclear. Western blot and real-time RT-PCR analysis were used to measure the expression of RFC3 in ovarian cancer cells. Lentivirus-mediated RFC3-specific shRNA was used to knock down RFC3 expression in ovarian cancer cells. Furthermore, the effect of RFC3 on tumor cellular proliferation and growth were examined, respectively. The expression level of RFC3 was remarkably up-regulated in ovarian cancer OVCAR-3 cells. With MTS and cell growth assays, the viability and proliferation of RFC3 knocking-down OVCAR-3 cell line were shown to be effectively restrained. Down-regulation of RFC3 expression arrested the cell cycle of OVCAR-3 cell in the S-phase and induced apoptosis. This study suggests that RFC3 may play an important role in the the process of ovarian carcinoma, and that it may be a potential biological treatment target in the future.