Hemorrhagic Shock-induced Bacterial Translocation: The Role of Neutrophils and Hydroxyl Radicals

This review summarizes published reports on the utility of melatonin as a treatment for virus-mediated diseases. Of special note are the data related to the role of melatonin in influencing Ebola virus disease. This infection and deadly condition has no effective treatment and the published works documenting the ability of melatonin to attenuate the severity of viral infections generally and Ebola infection specifically are considered. The capacity of melatonin to prevent one of the major complications of an Ebola infection, i.e., the hemorrhagic shock syndrome, which often contributes to the high mortality rate, is noteworthy. Considering the high safety profile of melatonin, the fact that it is easily produced, inexpensive and can be self-administered makes it an attractive potential treatment for Ebola virus pathology.

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Cisplatin-induced hydroxyl radicals mediate pro-survival autophagy in human lung cancer H460 cells

Biological Research ◽

10.1186/s40659-021-00346-2 ◽

2021 ◽

Vol 54 (1) ◽

Author(s):

Somruethai Sumkhemthong ◽

Eakachai Prompetchara ◽

Pithi Chanvorachote ◽

Chatchai Chaotham

Keyword(s):

Lung Cancer ◽

Hydroxyl Radicals ◽

Human Lung ◽

Human Lung Cancer ◽

Radical Scavenger ◽

Apoptosis Resistance ◽

Lung Cancer Patients ◽

Human Lung Cancer Cells ◽

H460 Cells

Abstract Background Accumulated evidence demonstrates cisplatin, a recommended chemotherapy, modulating pro-survival autophagic response that contributes to treatment failure in lung cancer patients. However, distinct mechanisms involved in cisplatin-induced autophagy in human lung cancer cells are still unclear. Results Herein, role of autophagy in cisplatin resistance was indicated by a decreased cell viability and increased apoptosis in lung cancer H460 cells pre-incubated with wortmannin, an autophagy inhibitor, prior to treatment with 50 µM cisplatin for 24 h. The elevated level of hydroxyl radicals detected via flow-cytometry corresponded to autophagic response, as evidenced by the formation of autophagosomes and autolysosomes in cisplatin-treated cells. Interestingly, apoptosis resistance, autophagosome formation, and the alteration of the autophagic markers, LC3-II/LC3-I and p62, as well as autophagy-regulating proteins Atg7 and Atg3, induced by cisplatin was abrogated by pretreatment of H460 cells with deferoxamine, a specific hydroxyl radical scavenger. The modulations in autophagic response were also indicated in the cells treated with hydroxyl radicals generated via Fenton reaction, and likewise inhibited by pretreatment with deferoxamine. Conclusions In summary, the possible role of hydroxyl radicals as a key mediator in the autophagic response to cisplatin treatment, which was firstly revealed in this study would benefit for the further development of novel therapies for lung cancer.

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Role of the C5a-C5a receptor axis in the inflammatory responses of the lungs after experimental polytrauma and hemorrhagic shock

Scientific Reports ◽

10.1038/s41598-020-79607-1 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Shinjini Chakraborty ◽

Veronika Eva Winkelmann ◽

Sonja Braumüller ◽

Annette Palmer ◽

Anke Schultze ◽

...

Keyword(s):

Hemorrhagic Shock ◽

Inflammatory Responses ◽

Experimental Models ◽

Lung Damage ◽

C5a Receptor ◽

Cytokine Levels ◽

Vitro Model

AbstractSingular blockade of C5a in experimental models of sepsis is known to confer protection by rescuing lethality and decreasing pro-inflammatory responses. However, the role of inhibiting C5a has not been evaluated in the context of sterile systemic inflammatory responses, like polytrauma and hemorrhagic shock (PT + HS). In our presented study, a novel and highly specific C5a L-aptamer, NoxD21, was used to block C5a activity in an experimental murine model of PT + HS. The aim of the study was to assess early modulation of inflammatory responses and lung damage 4 h after PT + HS induction. NoxD21-treated PT + HS mice displayed greater polymorphonuclear cell recruitment in the lung, increased pro-inflammatory cytokine levels in the bronchoalveolar lavage fluids (BALF) and reduced myeloperoxidase levels within the lung tissue. An in vitro model of the alveolar-capillary barrier was established to confirm these in vivo observations. Treatment with a polytrauma cocktail induced barrier damage only after 16 h, and NoxD21 treatment in vitro did not rescue this effect. Furthermore, to test the exact role of both the cognate receptors of C5a (C5aR1 and C5aR2), experimental PT + HS was induced in C5aR1 knockout (C5aR1 KO) and C5aR2 KO mice. Following 4 h of PT + HS, C5aR2 KO mice had significantly reduced IL-6 and IL-17 levels in the BALF without significant lung damage, and both, C5aR1 KO and C5aR2 KO PT + HS animals displayed reduced MPO levels within the lungs. In conclusion, the C5aR2 could be a putative driver of early local inflammatory responses in the lung after PT + HS.

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The DNA Sensor AIM2 Protects against Streptozotocin-Induced Type 1 Diabetes by Regulating Intestinal Homeostasis via the IL-18 Pathway

Cells ◽

10.3390/cells9040959 ◽

2020 ◽

Vol 9 (4) ◽

pp. 959 ◽

Cited By ~ 2

Author(s):

Jefferson Antônio Leite ◽

Gabriela Pessenda ◽

Isabel C. Guerra-Gomes ◽

Alynne Karen Mendonça de Santana ◽

Camila André Pereira ◽

...

Keyword(s):

Type 1 Diabetes ◽

Gut Microbiota ◽

Bacterial Translocation ◽

Intestinal Barrier ◽

Intestinal Barrier Function ◽

Dna Sensor ◽

Proinflammatory Response

Pattern recognition receptors (PRRs), such as Nod2, Nlrp3, Tlr2, Trl4, and Tlr9, are directly involved in type 1 diabetes (T1D) susceptibility. However, the role of the cytosolic DNA sensor, AIM2, in T1D pathogenesis is still unknown. Here, we demonstrate that C57BL/6 mice lacking AIM2 (AIM2−/−) are prone to streptozotocin (STZ)-induced T1D, compared to WT C57BL/6 mice. The AIM2−/− mice phenotype is associated with a greater proinflammatory response in pancreatic tissues, alterations in gut microbiota and bacterial translocation to pancreatic lymph nodes (PLNs). These alterations are related to an increased intestinal permeability mediated by tight-junction disruption. Notably, AIM2−/− mice treated with broad-spectrum antibiotics (ABX) are protected from STZ-induced T1D and display a lower pancreatic proinflammatory response. Mechanistically, the AIM2 inflammasome is activated in vivo, leading to an IL-18 release in the ileum at 15 days after an STZ injection. IL-18 favors RegIIIγ production, thus mitigating gut microbiota alterations and reinforcing the intestinal barrier function. Together, our findings show a regulatory role of AIM2, mediated by IL-18, in shaping gut microbiota and reducing bacterial translocation and proinflammatory response against insulin-producing β cells, which ultimately results in protection against T1D onset in an STZ-induced diabetes model.

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