Uvaol Prevents Group B Streptococcus-Induced Trophoblast Cells Inflammation and Possible Endothelial Dysfunction

Immunomodulatory effect of efferocytosis at the maternal-fetal interface

Efferocytosis is a mechanism by which phagocytes efficiently clear apoptotic cells, averting their secondary necrosis and the subsequent release of potentially immunogenic or cytotoxic substances that can trigger strong immune and inflammatory responses. During efferocytosis, the metabolic pathways of phagocytes are transformed, which, along with the catabolism of apoptotic cargo, can affect their function and inflammatory state. Extensive apoptosis occurs during placental development, and some studies reported the immunomodulatory effects of efferocytosis at the maternal-fetal interface. The dysregulation of efferocytosis is strongly linked to pregnancy complications such as preeclampsia and recurrent spontaneous abortion. In this review, we discuss the mechanisms of efferocytosis and its relationships with metabolism and inflammation. We also highlight the roles of professional and non-professional phagocytes in efferocytosis at the maternal-fetal interface and their impact on pregnancy outcomes and explore relevant regulatory factors. These insights are expected to guide future basic research and clinical strategies for identifying efferocytosis-related molecules as potential predictors or therapeutic targets in obstetric diseases.

Uvaol attenuates TGF-β1-induced epithelial-mesenchymal transition in human alveolar epithelial cells by modulating expression and membrane localization of β-catenin

The epithelial-mesenchymal transition (EMT) is a biological process in which epithelial cells change into mesenchymal cells with fibroblast-like characteristics. EMT plays a crucial role in the progression of fibrosis. Classical inducers associated with the maintenance of EMT, such as TGF-β1, have become targets of several anti-EMT therapeutic strategies. Natural products from the pentacyclic triterpene class have emerged as promising elements in inhibiting EMT. Uvaol is a pentacyclic triterpene found in olive trees (Olea europaea L.) known for its anti-inflammatory, antioxidant, and antiproliferative properties. Yet, its effect on the TGF-β1-induced EMT in alveolar epithelial cells is unknown. The present study aimed to investigate the impact of uvaol upon TGF-β1-induced EMT in a cultured A549 human alveolar epithelial cell line, a classic in vitro model for studies of EMT. Changes in cell shape were measured using phase-contrast and confocal microscopy, whereas protein expression levels were measured using immunofluorescence, flow cytometry, and Western blotting. We also performed wound scratch experiments to explore its effects on cell migration. Uvaol had no significant cytotoxic effects on A549 cells. By contrast, the changes in the cell morphology consistent with TGF-β1-induced EMT were largely suppressed by treatment with uvaol. In addition, increased contents of mesenchymal markers, namely, vimentin, N-cadherin, and fibronectin in TGF-β1-induced A549 cells, were downregulated by uvaol treatment. Furthermore, the TGF-β1-induced migration of A549 cells was significantly suppressed by uvaol. Mechanistically, uvaol prevented the nuclear translocation of β-catenin and reduced the TGF-β1-induced levels of ZEB1 in A549 cells. These results provide compelling evidence that uvaol inhibits EMT by regulating proteins related to the mesenchymal profile in human alveolar epithelial cells, likely by modulating β-catenin and ZEB1 levels.

Uvaol alleviates oxidative stress induced human umbilical vein endothelial cell injury by suppressing mitogen-activated protein kinase signaling pathway

Deep venous thrombosis (DVT) is a potentially life-threatening disorder with high morbidity. Uvaol is a natural pentacyclic triterpene possessing multiple pharmacological activities. Nevertheless, the role of uvaol in DVT is unclarified. Human umbilical vein endothelial cells (HUVECs) were treated with hydrogen peroxide (H 2 O 2 ) to mimic DVT in vitro . CCK-8 assay and flow cytometry were utilized for measuring cell viability and apoptosis, respectively. Levels of the cell injury marker, thrombosis-associated factors, inflammatory cytokines, and oxidative stress-related markers were examined by commercial assay kits. Western blotting was used for evaluating the expression of mitogen-activated protein kinase (MAPK) signaling-associated proteins. Uvaol treatment attenuated H 2 O 2 -induced HUVEC apoptosis and injury. Uvaol reduced the expression of pro-thrombotic factors and inflammatory cytokines and attenuated oxidative stress in H 2 O 2 -stimulated HUVECs. Uvaol inhibited MAPK signaling pathway in H 2 O 2 -stimulated HUVECs. Activating MAPK signaling reversed uvaol-mediated protective effects on H 2 O 2 -treated HUVECs. Uvaol treatment alleviates H 2 O 2 -induced HUVEC injury, apoptosis, and oxidative stress by inactivating MAPK signaling.

Sex-Specific Dysconnective Brain Injuries and Neuropsychiatric Conditions such as Autism Spectrum Disorder Caused by Group B Streptococcus-Induced Chorioamnionitis

Global health efforts have increased against infectious diseases, but issues persist with pathogens like Group B Streptococcus (GBS). Preclinical studies have elaborated on the mechanistic process of GBS-induced chorioamnionitis and its impact on the fetal programming of chronic neuropsychiatric diseases. GBS inoculation in rodents demonstrated the following: (i) silent and self-limited placental infection, similar to human chorioamnionitis; (ii) placental expression of chemokines attracting polymorphonuclear (PMN) cells; (iii) in vitro cytokine production; (iv) PMN infiltration in the placenta (histologic hallmark of human chorioamnionitis), linked to neurobehavioral impairments like cerebral palsy and autism spectrum disorders (ASD); (v) upregulation of interleukin-1β (IL-1β) in the placenta and fetal blood, associated with higher ASD risk in humans; (vi) sex-specific effects, with higher IL-1β release and PMN recruitment in male placenta; (vii) male offspring exhibiting ASD-like traits, while female offspring displayed attention deficit and hyperactivity disorder (ADHD)-like traits; (viii) IL-1 and/or NF-kB blockade alleviate placental and fetal inflammation, as well as subsequent neurobehavioral impairments. These findings offer potential therapeutic avenues, including sex-adapted anti-inflammatory treatment (e.g., blocking IL-1; repurposing of FDA-approved IL-1 receptor antagonist (IL-1Ra) treatment). Blocking the IL-1 pathway offers therapeutic potential to alleviate chorioamnionitis-related disabilities, presenting an opportunity for a human phase II RCT that uses IL-1 blockade added to the classic antibiotic treatment of chorioamnionitis.

Animal Models of Chorioamnionitis: Considerations for Translational Medicine

Preterm birth is defined as any birth occurring before 37 completed weeks of gestation by the World Health Organization. Preterm birth is responsible for perinatal mortality and long-term neurological morbidity. Acute chorioamnionitis is observed in 70% of premature labor and is associated with a heavy burden of multiorgan morbidities in the offspring. Unfortunately, chorioamnionitis is still missing effective biomarkers and early placento- as well as feto-protective and curative treatments. This review summarizes recent advances in the understanding of the underlying mechanisms of chorioamnionitis and subsequent impacts on the pregnancy outcome, both during and beyond gestation. This review also describes relevant and current animal models of chorioamnionitis used to decipher associated mechanisms and develop much needed therapies. Improved knowledge of the pathophysiological mechanisms underpinning chorioamnionitis based on preclinical models is a mandatory step to identify early in utero diagnostic biomarkers and design novel anti-inflammatory interventions to improve both maternal and fetal outcomes.