The medical team from Xiangya Hospital to support Hubei, China

Background:Pyroptosis is the term for caspase-1-dependent cell death associated with pro-inflammatory cytokines. The role of alveolar macrophage (AM) pyroptosis in the pathogenesis of the acute lung injury and acute respiratory distress syndrome (ALI/ARDS) remains unclear.Methods:C57BL/6 wild-type mice were assigned to sham, lipopolysaccharide (LPS) + vehicle, LPS + acetyl-tyrosyl-valyl- alanyl-aspartyl-chloromethylketone (Ac-YVAD-CMK) and LPS + Z-Asp-Glu-Val-Asp-fluoromethylketone groups. Mice were given intraperitoneal (IP) injections of LPS. Drugs were IP injected 1 h before LPS administration. Mice were sacrificed 16 h after LPS administration, and AMs were isolated. Western blot analysis for active caspase-1 and cleaved caspase-3, evaluation of lung injury and a cytokine release analysis were performed. AMs were treated with LPS and adenosine triphosphate (ATP); caspase-1-dependent cell death was evaluated using flow cytometry; the apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) pyroptosomes were examined by immunofluorescence.Results:The expression of activated caspase-1 in AMs was enhanced following LPS challenge compared with the sham group. In the ex vivo study, the caspase-1/propidium iodide-positive cells, caspase-1 specks and ASC pyroptosomes were up-regulated in AMs following LPS/ATP stimulation. The specific caspase-1 inhibitor Ac-YVAD-CMK inhibited the activation of caspase-1 and pyroptotic cell death. Ac-YVAD-CMK also reduced the lung injury, pulmonary edema and total protein in bronchoalveolar lavage fluid (BALF). In addition, Ac-YVAD-CMK significantly inhibited interleukin-β (IL-1β) release both in serum and BALF and reduced the levels of IL-18, tumor necrosis factor-α (TNF-α), High Mobility Group Box 1 (HMGB1) in BALF during LPS-induced ALI/ARDS.Conclusions:This study reported AM pyroptosis during LPS-induced ALI/ARDS in mice and has demonstrated that Ac-YVAD-CMK can prevent AM-induced pyroptosis and lung injury. These preliminary findings may form the basis for further studies to evaluate this pathway as a target for prevention or reduction of ALI/ARDS.

Activation of the cholinergic anti-inflammatory pathway (CAP), which relies on the alpha-7 nicotinic acetylcholine receptor, has been reported to reduce proinflammatory cytokine levels in experimental arthritis. To gain more insight regarding the role of the CAP in the pathogenesis of arthritis, the present study focused on the modulation of macrophage infiltration. In a mouse model of collagen-induced arthritis (CIA), nicotine and vagotomy were used to stimulate and inhibit the CAP, respectively. Subsequently, arthritic scores were measured and histopathological assessment of joint sections was conducted. Cluster of differentiation (CD)11b-positive macrophages in the synovium were studied by immunofluorescence histochemistry. The serum levels of chemokines, including macrophage inflammatory protein (MIP)-1α, monocyte chemoattractant protein (MCP)-1 and MIP-2 were evaluated by ELISA. Furthermore, the expression levels of C-C chemokine receptor (CCR)2 and intercellular adhesion molecule (ICAM)-1 in the synovium were evaluated by immunohistochemical staining. The results indicated that treatment with nicotine significantly attenuated the clinical and histopathological changes associated with arthritis, reduced CD11b-positive macrophages in the synovium, and downregulated the serum expression levels of MIP-1α and MCP-1. Conversely, vagotomy aggravated arthritis and upregulated the expression levels of MCP-1. However, MIP-2 expression did not differ among the control, CIA, vagotomy and nicotine groups. In addition, the expression levels of CCR2 were reduced in the nicotine group; however, they were increased in the vagotomy group compared with in the untreated CIA group. The expression levels of ICAM-1 in the synovium were also influenced by activation of the CAP. Taken together, the present results indicated that nicotine-induced activation of the CAP in mice with CIA may reduce the number of macrophages in the synovium, which may serve a role in alleviating arthritis in mice.

Lung adenocarcinoma, which is the most common non-small cell lung cancer, is the leading cause of death from cancer worldwide. Epithelial cell transforming sequence 2 (ECT2) is frequently upregulated and acts as an oncogene in various human cancers. In addition, ECT2 was reported to be upregulated in early stage lung adenocarcinoma. However, the detailed role of ECT2 in mediating the malignant phenotypes of lung adenocarcinoma cells has not previously been elucidated. Reverse transcription-quantitative polymerase chain reaction and western blot analysis were used to examine ECT2 mRNA and protein expression levels, respectively. MTT, wound healing and Transwell assays were conducted to determine cell proliferation, migration and invasion abilities, respectively. In the present study, ECT2 was significantly upregulated in lung adenocarcinoma cell lines (H650, EKVX, HCC4006, HCC827, HCC2935, Hop62 and A549), as compared with a normal lung epithelial cell line (BEAS-2B). Moreover, knockdown of ECT2, induced by transfection with ECT2 siRNA, significantly inhibited the proliferation of lung adenocarcinoma A549 cells, whereas overexpression of ECT2 enhanced A549 cell proliferation. Furthermore, knockdown of ECT2 expression suppressed the migration and invasion of A549 cells, whereas overexpression of ECT2 enhanced the migration and invasion abilities of A549 cells. Notably, inhibition of ECT2 also suppressed the expression levels of N-cadherin and vimentin, whereas it enhanced the expression level of E-cadherin, indicating that ECT2 is associated with the epithelial-mesenchymal transition in A549 cells. On the contrary, overexpression of ECT2 enhanced the expression levels of N-cadherin and vimentin, whereas it reduced the expression level of E-cadherin in A549 cells. In conclusion, the results of the present study suggest that ECT2 has an oncogenic role in lung adenocarcinoma cells. Therefore, ECT2 may be a potential novel target for the treatment of lung adenocarcinoma.

NGF facilitates OVA with lowLPS-induced maturation of mouse BMDCs through LPS-up-regulated p75 NTR via activation of NF-κB pathways, providing another mechanism for the involvement of NGF in the Th2 response.