WWOX activates autophagy to alleviate lipopolysaccharide-induced acute lung injury by regulating mTOR.

Acute lung injury (ALI) is characterized by acute systemic inflammatory responses that may lead to severe acute respiratory distress syndrome (ARDS). The clinical course of ALI/ARDS is variable; however, it has been reported that lipopolysaccharides (LPS) play a role in its development. The fragile chromosomal site gene WWOX is highly sensitive to genotoxic stress induced by environmental exposure and is an important candidate gene for exposure-related lung disease research. However, the expression of WWOX and its role in LPS-induced ALI still remain unidentified. This study investigated the expression of WWOX in mouse lung and epithelial cells and explored the role of WWOX in LPS-induced ALI model in vitro and in vivo. In addition, we explored one of the possible mechanisms by which WWOX alleviates ALI from the perspective of autophagy. Here, we observed that LPS stimulation reduced the expression of WWOX and the autophagy marker microtubule-associated protein 1 light chain 3ß-II (MAP1LC3B/LC3B) in mouse lung epithelial and human epithelial (H292) cells. Overexpression of WWOX led to the activation of autophagy and inhibited inflammatory responses in LPS-induced ALI cells and mouse model. More importantly, we found that WWOX interacts with mechanistic target of rapamycin [serine/threonine kinase] (mTOR) and regulates mTOR and ULK-1 signaling-mediated autophagy. Thus, reduced WWOX levels were associated with LPS-induced ALI. WWOX can activate autophagy in lung epithelial cells and protect against LPS-induced ALI, which is partly related to the mTOR-ULK1 signaling pathway.

Injection Effect of Anti-CD3 Monoclonal Antibody on Primo Vessel in Lymph Vessel of Rabbit with Lipopolysaccharide-Induced Inflammation.

Background: The primo vascular system can be viewed as a circulatory system that plays a therapeutic function in regenerating the body tissue. The anti-CD3 monoclonal antibody was used as an immunotherapeutic agent to treat the novel coronavirus infection (COVID-19). Objectives: In this study, we observed the effect of injecting lymph nodes with Foralumab, an anti- human CD3 epsilon therapeutic monoclonal antibody, on primo vessels. Methods: The structure and atomic stoichiometry of the antibody were determined by transmission electron microscopy and energy dispersive spectroscopy. Alcian blue dying solution was injected into the lymph nodes of the abdominal vena cava of rabbits, and the solution further flowed into the lymph vessels. Results: A primo vessel with primo nodes stained with Alcian blue was clearly visible in the lymph vessel. By injecting Foralumab into lymph nodes of rabbits with lipopolysaccharide-induced inflammation, the floating primo vessel in the lymph vessel appeared thicker and was distinctly visible. Conclusion: The observation of the primo vessel post-treated with Foralumab in the inflamed lymphatic system suggests the possibility of a functional role of the primo vascular circulatory system in pathophysiological conditions.

ACE2 Is Expressed in Immune Cells That Infiltrate the Placenta in Infection-Associated Preterm Birth.

COVID-19 is associated with increased incidence of preterm birth (PTB). We assessed pathways by which SARS-CoV-2 could access the placenta. Placentae, from PTB with or without chorioamnionitis (ChA), or from term pregnancies (n = 12/13/group) were collected. Peripheral blood was collected from healthy pregnant women (n = 6). Second trimester placental explants (16-20 weeks, n = 5/group) were treated with lipopolysaccharide (LPS, to mimic bacterial infection) and ACE2, CCL2, IL-6/8 and TNFα mRNA was assessed. ChA-placentae exhibited increased ACE2 and CCL2 mRNA expression (p < 0.05). LPS increased cytokine and ACE2 mRNA in placental explants. Placental ACE2 protein localized to syncytiotrophoblast, fetal endothelium, extravillous trophoblast and in immune cells-subsets (M1/M2 macrophage and neutrophils) within the villous stroma. Significantly increased numbers of M1 macrophage and neutrophils were present in the ChA-placenta (p < 0.001). Subsets of peripheral immune cells from pregnant women express the ACE2 mRNA and protein. A greater fraction of granulocytes was positive for ACE2 protein expression compared to lymphocytes or monocytes. These data suggest that in pregnancies complicated by ChA, ACE2 positive immune cells in the maternal circulation have the potential to traffic SARS-CoV-2 virus to the placenta and increase the risk of vertical transmission to the placenta/fetus.

Resveratrol-mediated attenuation of superantigen-driven acute respiratory distress syndrome is mediated by microbiota in the lungs and gut.

Acute Respiratory Distress Syndrome (ARDS) is triggered by a variety of agents, including Staphylococcal Enterotoxin B (SEB). Interestingly, a significant proportion of patients with COVID-19, also develop ARDS. In the absence of effective treatments, ARDS results in almost 40% mortality. Previous studies from our laboratory demonstrated that resveratrol (RES), a stilbenoid, with potent anti-inflammatory properties can attenuate SEB-induced ARDS. In the current study, we investigated the role of RES-induced alterations in the gut and lung microbiota in the regulation of ARDS. Our studies revealed that SEB administration induced inflammatory cytokines, ARDS, and 100% mortality in C3H/HeJ mice. Additionally, SEB caused a significant increase in pathogenic Proteobacteria phylum and Propionibacterium acnes species in the lungs. In contrast, RES treatment attenuated SEB-mediated ARDS and mortality in mice, and significantly increased probiotic Actinobacteria phylum, Tenericutes phylum, and Lactobacillus reuteri species in both the colon and lungs. Colonic Microbiota Transplantation (CMT) from SEB-injected mice that were treated with RES as well as the transfer of L. reuteri into recipient mice inhibited the production of SEB-mediated induction of pro-inflammatory cytokines such as IFN-γ and IL-17 but increased that of anti-inflammatory IL-10. Additionally, such CMT and L. reuteri recipient mice exposed to SEB, showed a decrease in lung-infiltrating mononuclear cells, cytotoxic CD8+ T cells, NKT cells, Th1 cells, and Th17 cells, but an increase in the population of regulatory T cells (Tregs) and Th3 cells, and increase in the survival of mice from SEB-mediated ARDS. Together, the current study demonstrates that ARDS induced by SEB triggers dysbiosis in the lungs and gut and that attenuation of ARDS by RES may be mediated, at least in part, by alterations in microbiota in the lungs and the gut, especially through the induction of beneficial bacteria such as L. reuteri.

Endotheliopathy in septic conditions: mechanistic insight into intravascular coagulation.

Endothelial cells play a key role in maintaining intravascular patency through their anticoagulant properties. They provide a favorable environment for plasma anticoagulant proteins, including antithrombin, tissue factor pathway inhibitor, and protein C. Under septic conditions, however, the anticoagulant properties of endothelial cells are compromised. Rather, activated/injured endothelial cells can provide a scaffold for intravascular coagulation. For example, the expression of tissue factor, an important initiator of the coagulation pathway, is induced on the surface of activated endothelial cells. Phosphatidylserine, a high-affinity scaffold for gamma-carboxyglutamate domain containing coagulation factors, including FII, FVII, FIX, and FX, is externalized to the outer leaflet of the plasma membrane of injured endothelial cells. Hemodilution decreases not only coagulation factors but also plasma anticoagulant proteins, resulting in unleashed activation of coagulation on the surface of activated/injured endothelial cells. The aberrant activation of coagulation can be suppressed in part by the supplementation of recombinant antithrombin and recombinant thrombomodulin. This review aims to overview the physiological and pathological functions of endothelial cells along with proof-of-concept in vitro studies. The pathophysiology of COVID-19-associated thrombosis is also discussed.