Associations between vaginal microbiota and endometrial polypoid lesions in women of reproductive age: a cross-sectional study.

RESEARCH QUESTION: What are the different characteristics of vaginal microbial composition between patients with endometrial polypoid lesions and controls? DESIGN: This cohort study compared the pre-operative microbial compositions of vaginal samples in a cohort of 703 women with endometrial polypoid lesions [293 and 410 women diagnosed and not diagnosed with polyps pathologically (polyps group and not-polyps group, respectively] and 703 women in the control group. Bacterial abundance, diversity, differential taxa and microbial network structure were assessed using 16S rRNA gene sequencing. Predictive algorithms were used to determine the functional pathways of vaginal microbiota within the cohort. RESULTS: The control group exhibited higher relative abundance of Lactobacillus crispatus in comparison with the polypoid lesions group (P = 0.0427). Beta diversity of vaginal microbiota differed significantly between the groups (P < 0.05). Comparing the polyps group with the not-polyps group, Leptotrichia spp. and Cutibacterium spp. were more abundant in the polyps group, and Fannyhessea spp., Acinetobacter spp. and Achromobacter spp. were more abundant in the not-polyps group. The control group exhibited higher abundance of Bifidobacterium spp., Achromobacter spp. and Escherichia/Shigella spp. (false discovery rate < 0.05). Furthermore, the polyps group and not-polyps group displayed more complex co-occurrence networks compared with the control group. CONCLUSIONS: The results of this study provide compelling evidence supporting associations between vaginal microbiota and endometrial polypoid lesions, highlighting the potential relationship between a well-balanced vaginal microbial ecosystem and a healthy intrauterine environment.

Association between Pregestational Vaginal Dysbiosis and Incident Hypertensive Disorders of Pregnancy Risk: a Nested Case-Control Study.

A balanced vaginal microbiome dominated by Lactobacillus can help promote women's reproductive health, with Lactobacillus crispatus showing the most beneficial effect. However, the potential role of vaginal microbiomes in hypertensive disorders of pregnancy (HDP) development is not thoroughly explored. In this nested case-control study based on an assisted reproductive technology follow-up cohort, we prospectively assessed the association between pregestational vaginal microbiomes with HDP by collecting vaginal swabs from 75 HDP cases (HDP group) and 150 controls (NP group) and using 16S amplicon sequencing for bacterial identification. The vaginal microbial composition of the HDP group significantly differed from that of the NP group. The abundance of L. crispatus was significantly lower, and the abundances of Gardnerella vaginalis was significantly higher, in the HDP group than in the NP group. Of note, L. crispatus-dominated vaginal community state type was associated with a decreased risk for HDP (odds ratio = 0.436; 95% confidence interval, 0.229 to 0.831) compared with others. Additionally, network analysis revealed different bacterial interactions with 61 and 57 exclusive edges in the NP and HDP groups, respectively. Compared with the HDP group, the NP group showed a higher weighted degree and closeness centrality. Several taxa, including G. vaginalis, L. iners, and bacterial vaginosis-associated bacteria (Prevotella, Megasphaera, Finegoldia, and Porphyromonas), were identified as "drivers" for network rewiring. Notable alterations of predicted pathways involved in amino acid, cofactor, and vitamin metabolism; membrane transport; and bacterial toxins were observed in the HDP group. IMPORTANCE The etiology of HDP remains unclear to date. Effective methods for the individualized prediction and prevention are lacking. Pregestational vaginal dysbiosis precedes the diagnosis of HDP, providing a novel perspective on the etiology of HDP. Early pregnancy is the critical period of placental development, and abnormal placentation initiates HDP development. Thus, disease prevention should be considered before pregnancy. Vaginal microbiome characterization and probiotic interventions before pregnancy are preferred because of their safety and potential for early prevention. This study is the first to prospectively assess associations between pregestational vaginal microbiome and HDP. L. crispatus-dominated vaginal community state type is linked to a reduced risk for HDP. These findings suggest that vaginal microbiome characterization may help identify individuals at high risk for HDP and offer potential targets for the development of novel pregestational intervention methods.

Autonomous sensing of the insulin peptide by an olfactory G protein-coupled receptor modulates glucose metabolism.

Along with functionally intact insulin, diabetes-associated insulin peptides are secreted by ß cells. By screening the expression and functional characterization of olfactory receptors (ORs) in pancreatic islets, we identified Olfr109 as the receptor that detects insulin peptides. The engagement of one insulin peptide, insB:9-23, with Olfr109 diminished insulin secretion through Gi-cAMP signaling and promoted islet-resident macrophage proliferation through a ß cell-macrophage circuit and a ß-arrestin-1-mediated CCL2 pathway, as evidenced by ß-arrestin-1-/- mouse models. Systemic Olfr109 deficiency or deficiency induced by Pdx1-Cre+/-Olfr109fl/fl specifically alleviated intra-islet inflammatory responses and improved glucose homeostasis in Akita- and high-fat diet (HFD)-fed mice. We further determined the binding mode between insB:9-23 and Olfr109. A pepducin-based Olfr109 antagonist improved glucose homeostasis in diabetic and obese mouse models. Collectively, we found that pancreatic ß cells use Olfr109 to autonomously detect self-secreted insulin peptides, and this detection arrests insulin secretion and crosstalks with macrophages to increase intra-islet inflammation.

Structural Mechanism of the Arrestin-3/JNK3 Interaction.

Arrestins, in addition to desensitizing GPCR-induced G protein activation, also mediate G protein-independent signaling by interacting with various signaling proteins. Among these, arrestins regulate MAPK signal transduction by scaffolding mitogen-activated protein kinase (MAPK) signaling components such as MAPKKK, MAPKK, and MAPK. In this study, we investigated the binding mode and interfaces between arrestin-3 and JNK3 using hydrogen/deuterium exchange mass spectrometry, 19F-NMR, and tryptophan-induced Atto 655 fluorescence-quenching techniques. Results suggested that the ß1 strand of arrestin-3 is the major and potentially only interaction site with JNK3. The results also suggested that C-lobe regions near the activation loop of JNK3 form the potential binding interface, which is variable depending on the ATP binding status. Because the ß1 strand of arrestin-3 is buried by the C-terminal strand in its basal state, C-terminal truncation (i.e., pre-activation) of arrestin-3 facilitates the arrestin-3/JNK3 interaction.

Identification and structure-function analyses of an allosteric inhibitor of the tyrosine phosphatase PTPN22.

Protein-tyrosine phosphatase nonreceptor type 22 (PTPN22) is a lymphoid-specific tyrosine phosphatase (LYP), and mutations in the PTPN22 gene are highly correlated with a spectrum of autoimmune diseases. However, compounds and mechanisms that specifically inhibit LYP enzymes to address therapeutic needs to manage these diseases remain to be discovered. Here, we conducted a similarity search of a commercial database for PTPN22 inhibitors and identified several LYP inhibitor scaffolds, which helped identify one highly active inhibitor, NC1. Using noncompetitive inhibition curve and phosphatase assays, we determined NC1's inhibition mode toward PTPN22 and its selectivity toward a panel of phosphatases. We found that NC1 is a noncompetitive LYP inhibitor and observed that it exhibits selectivity against other protein phosphatases and effectively inhibits LYP activity in lymphoid T cells and modulates T-cell receptor signaling. Results from site-directed mutagenesis, fragment-centric topographic mapping, and molecular dynamics simulation experiments suggested that NC1, unlike other known LYP inhibitors, concurrently binds to a "WPD" pocket and a second pocket surrounded by an LYP-specific insert, which contributes to its selectivity against other phosphatases. Moreover, using a newly developed method to incorporate the unnatural amino acid 2-fluorine-tyrosine and 19F NMR spectroscopy, we provide direct evidence that NC1 allosterically regulates LYP activity by restricting WPD-loop movement. In conclusion, our approach has identified a new allosteric binding site in LYP useful for selective LYP inhibitor development; we propose that the 19F NMR probe developed here may also be useful for characterizing allosteric inhibitors of other tyrosine phosphatases.