Costunolide attenuates LPS-induced inflammation and lung injury through inhibiting IKK/NF-κB signaling.

Inflammation is an important pathological process of many acute and chronic diseases, such as sepsis, arthritis, and cancer. Many factors can lead to an inflammatory state of the body, among which bacterial infection plays an important role. Bacterial infection often leads to sepsis, acute lung injury (ALI), or its more serious form of acute respiratory distress syndrome, which are the main fatal diseases in intensive care units. Costunolide has been reported to possess excellent anti-inflammatory activity; however, whether it can affect inflammation induced by gram-negative bacterial is still unclear. Lipopolysaccharide (LPS) stimulated mouse peritoneal macrophages (MPMs) to release proinflammatory cytokines was used as the cell model. The mouse model of sepsis and ALI was built through injecting intravenously and intratracheally of LPS. In the present study, costunolide inhibited LPS-induced inflammatory response through IKK/NF-κB signaling pathway in macrophages. In vivo, costunolide attenuated LPS-induced septic death in mice. Meanwhile, costunolide treatment alleviated LPS-induced lung injury and inflammation via inhibiting the infiltration of inflammatory cells and the expression of inflammatory cytokines. Taken together, these results demonstrated that costunolide could attenuate gram-negative bacterial induced inflammation and diseases and might be a potential candidate for the treatment of inflammatory diseases.

Piperlongumine mitigates LPS-induced inflammation and lung injury via targeting MD2/TLR4.

PURPOSE: Acute lung injury (ALI) is a fatal acute inflammatory illness with restricted therapeutic choices clinically. Piperlongumine (PL) is recognized as an alkaloid separated from Piper longum L, which was suggested to exhibit multiple pharmacological activities (e.g., anti-inflammatory activity). However, the effects of PL on LPS-triggered ALI and its anti-inflammatory target remain unclear. This paper intended to assess the roles of PL in LPS-triggered ALI, as well as its underlying mechanism and target. METHODS: In vivo, ALI was induced by intratracheal injection of LPS to evaluate protective effects of PL and assessed by the changes of histopathological. In vitro, the anti-inflammatory activity and mechanism of PL were investigated by ELISA, RT-qPCR, transcription factor enrichment analysis, Western blotting and Immunofluorescence assay. The binding affinity of PL to MD2 was analyzed using computer docking, surface plasmon resonance, ELISA and immunoprecipitation assay. RESULTS: It was reported here that PL treatment alleviated LPS-induced pulmonary damage, inflammatory cells infiltration and inflammatory response in mice. In culture cells, PCR array showed that PL significantly inhibited LPS-induced inflammatory cytokines, chemokines, and type I IFNs genetic expression, along with the inhibition of TAK1 and TBK1 pathway. It is noteworthy that PL is capable of straightly binding to MD2 and inhibiting MD2/TLR4 complex formation and TLR4 dimerization. CONCLUSIONS: As revealed from this study, PL directly binding to MD2 to block cytokines expression by inhibiting the activation of TAK1 and TBK1 pathway, which then exerted its pulmonary protective activity. Accordingly, PL may act as an underlying candidate for treating LPS-triggered ALI.

cyy-287, a novel pyrimidine-2,4-diamine derivative, inhibits tumor growth of EGFR-driven non-small cell lung cancer via the ERK pathway.

In recent decades, EGFR-targeted tyrosine kinase inhibitors (TKIs) have been proven to be an effective therapy for EGFR-mutant non-small cell lung cancer (NSCLC). However, resistance to EGFR-TKIs limits their clinical application. In the present study, we investigate the antitumor effect and underlying mechanism of a novel pyrimidine-2,4-diamine derivative, cyy-287, in NSCLC. We find that cyy-287 has a high affinity for lung tissue and inhibits the proliferation of NSCLC cells. Interestingly, the significant suppression of migration and induction of apoptosis by cyy-287 are only observed in EGFR-driven but not in EGFR-wild-type (wt) cells. According to the RNA sequencing and KEGG enrichment analysis results, cyy-287 markedly inhibits the MAPK pathway in EGFR-driven PC9 cells, and western blot analysis results further indicate that cyy-287 selectively blocks the ERK pathway in EGFR-driven cells. Meanwhile, apoptosis induced by cyy-287 could be partially reversed by ERK pathway inhibition. Further experiment indicates that cyy-287 inhibits the EGFR pathway in both EGFR-driven and EGFR-overexpressing cells. Interestingly, it only induces apoptosis in EGFR-driven cells, not in EGFR-overexpressing cells. The growth of EGFR-driven cells is suppressed by cyy-287 in vivo, with fewer side effects. Our results suggest that cyy-287 may be a potential therapeutic drug with promising antitumor effects against NSCLC.

Macrophage-specific MyD88 deletion and pharmacological inhibition prevents liver damage in non-alcoholic fatty liver disease via reducing inflammatory response.

Activation of the innate immune system through toll-like receptors (TLRs) has been repeatedly demonstrated in non-alcoholic fatty liver disease (NAFLD) and several TLRs have been shown to contribute. Myeloid differentiation primary response 88 (MyD88) is as an adapter protein for the activation of TLRs and bridges TLRs to NF-κB-mediated inflammation in macrophages. However, whether myeloid cell MyD88 contributes to NAFLD are largely unknown. To test this approach, we generated macrophage-specific MyD88 knockout mice and show that these mice are protected against high-fat diet (HFD)-induced hepatic injury, lipid accumulation, and fibrosis. These protective effects were associated with reduced macrophage numbers in liver tissues and surpassed inflammatory responses. In cultured macrophages, saturated fatty acid palmitate utilizes MyD88 to activate NF-κB and induce inflammatory and fibrogenic factors. In hepatocytes, these factors may cause lipid accumulation and a further elaboration of inflammatory cytokines. In hepatic stellate cells, macrophage-derived factors, especially TGF-ß, cause activation and hepatic fibrosis. We further show that pharmacological inhibition of MyD88 is also able to reduce NAFLD injury in HFD-fed mice. Therefore, our study has provided empirical evidence that macrophage MyD88 participates in HFD-induced NAFLD and could be targeted to prevent the development and progression of NAFLD/NASH.

Chalcone derivatives ameliorate lipopolysaccharide-induced acute lung injury and inflammation by targeting MD2.

Acute lung injury (ALI) and its severe form acute respiratory distress syndrome (ARDS) are known as the common causes of respiratory failure in critically ill patients. Myeloid differentiation 2 (MD2), a co-receptor of toll like receptor 4 (TLR4), plays an important role in LPS-induced ALI in mice. Since MD2 inhibition by pharmacological inhibitors or gene knockout significantly attenuates ALI in animal models, MD2 has become an attractive target for the treatment of ALI. In this study we identified two chalcone-derived compounds, 7w and 7x, as new MD2 inhibitors, and investigated the therapeutic effects of 7x and 7w in LPS-induced ALI mouse model. In molecular docking analysis we found that 7w and 7x, formed pi-pi stacking interactions with Phe151 residue of the MD2 protein. The direct binding was confirmed by surface plasmon resonance analysis (with KD value of 96.2 and 31.2 µM, respectively) and by bis-ANS displacement assay. 7w and 7x (2.5, 10 µM) also dose-dependently inhibited the interaction between lipopolysaccharide (LPS) and rhMD2 and LPS-MD2-TLR4 complex formation. In mouse peritoneal macrophages, 7w and 7x (1.25-10 µM) dose-dependently inhibited LPS-induced inflammatory responses, MAPKs (JNK, ERK and P38) phosphorylation as well as NF-κB activation. Finally, oral administration of 7w or 7x (10 mg ·kg-1 per day, for 7 days prior LPS challenge) in ALI mouse model significantly alleviated LPS-induced lung injury, pulmonary edema, lung permeability, inflammatory cells infiltration, inflammatory cytokines expression and MD2/TLR4 complex formation. In summary, we identify 7w and 7x as new MD2 inhibitors to inhibit inflammatory response both in vitro and in vivo, proving the therapeutic potential of 7w and 7x for ALI and inflammatory diseases.

Selenium-Containing Compound Ameliorates Lipopolysaccharide-Induced Acute Lung Injury via Regulating the MAPK/AP-1 Pathway.

Abstract-Acute lung injury (ALI) is characterized by a series of inflammatory reactions and serves as the main cause of mortality in intensive care unit patients. Although great progress has been made in understanding the pathophysiology of ALI, there are no effective treatments in clinic. Recently, we have synthesized a selenium-containing compound, which possesses obvious anti-inflammatory activity. The aim of the present study is to evaluate the protective effects of the selenium-containing compound 34# in LPS-induced ALI in mice as well as its underlying mechanism. Compound 34# was found to inhibit LPS-induced macrophage inflammatory cytokine release. These effects were observed to be produced via suppression of the MAPK/AP-1 pathway. Compound 34# was also noted to attenuate the LPS-induced lung inflammation in mice with ALI. The corresponding results suggested that compound 34# possesses remarkable protective effects on LPS-induced ALI. Furthermore, the MAPK/AP-1 pathway may prove to be the underlying mechanism. Accordingly, compound 34# may serve as a potential candidate for the prevention of ALI.

Inhibition of MyD88 by LM8 Attenuates Obesity-Induced Cardiac Injury.

Obesity-induced cardiomyopathy involves chronic and sustained inflammation. The toll-like receptor 4 (TLR4) signaling pathway can associate innate immunity with obesity. Myeloid differentiation primary response 88 (MyD88), an indispensable downstream adaptor molecule of TLR4, has been reported to mediate obesity complications. However, whether inhibition of MyD88 can mitigate obesity-induced heart injury remains unclear. LM8, a new MyD88 inhibitor, exhibits prominent anti-inflammatory activity in lipopolysaccharide-treated macrophages. In this study, the protective effects of LM8 on a high-fat diet (HFD)-induced heart injury were assessed in a mouse model of obesity. As suggested from the achieved results, LM8 treatment alleviated HFD-induced pathological and functional damages of the heart in mice. Meantime, the treatment of mice with LM8 could significantly inhibit myocardial hypertrophy, fibrosis, inflammatory cytokines expression, and inflammatory cell infiltration induced by HFD. Besides, LM8 administration inhibited the formation of MyD88/TLR4 complex, phosphorylation of ERK, and activation of nuclear factor-κB induced by HFD. According to the achieved results, MyD88 inhibitor LM8 ameliorated obesity-induced heart injury by inhibiting MyD88-ERK/nuclear factor-κB dependent cardiac inflammatory pathways. Furthermore, targeting MyD88 might be a candidate of a therapeutic method to treat obesity-induced heart injury.