Targeting TLR4 and regulating the Keap1/Nrf2 pathway with andrographolide to suppress inflammation and ferroptosis in LPS-induced acute lung injury

Acute lung injury(ALI)is a severe inflammatory condition with a high mortality rate,often precipitated by sepsis.The pathophysiology of ALI involves complex mechanisms,including inflammation,oxidative stress,and ferroptosis,a novel form of regulated cell death.This study explores the therapeutic potential of andrographolide(AG),a bioactive compound derived from Andrographis,in mitigating Lipopolysaccharide(LPS)-induced inflammation and ferroptosis.Our research employed in vitro experiments with RAW264.7 macrophage cells and in vivo studies using a murine model of LPS-induced ALI.The results indicate that AG significantly suppresses the production of pro-inflammatory cytokines and inhibits ferroptosis in LPS-stimulated RAW264.7 cells.In vivo,AG treatment markedly reduces lung edema,decreases inflammatory cell infiltration,and mitigates ferroptosis in lung tissues of LPS-induced ALI mice.These protective effects are mediated via the modulation of the Toll-like receptor 4(TLR4)/Kelch-like ECH-associated protein 1(Keap1)/Nuclear factor erythroid 2-related factor 2(Nrf2)signaling pathway.Molecular docking simulations identified the binding sites of AG on the TLR4 protein(Kd value:-33.5 kcal·mol^(-1)),and these interactions were further corroborated by Cellular Thermal Shift Assay(CETSA)and SPR assays.Collectively,our findings demonstrate that AG exerts potent anti-inflammatory and anti-ferroptosis effects in LPS-induced ALI by targeting TLR4 and modulating the Keap1/Nrf2 pathway.This study underscores AG's potential as a therapeutic agent for ALI and provides new insights into its underlying mechanisms of action.

Diagnostic and Prognostic Significance of Keapl mRNA Expression for Lung Cancer Based on Microarray and Clinical Information from Oncomine Database

We performed a bioinformatics analysis with validation by multiple databases,aiming to evaluate the diagnostic and prognostic value of Kelch-like ECH-associated protein 1(Keapl)mRNA for lung cancer,and to explore possible mechanisms.Diagnostic performance of Keapl mRNA was determined by receiver operating characteristic(ROC)curve analysis.Prognostic implication of Keapl mRNA was estimated by Kaplan-Meier survival analysis.Co-expressed genes with both Keapl and Nfe2L2 were identified by LinkedOmics.Mechanisms of Keapl-Nfe2L2-co-expressed genes underlying the pathogenesis of lung cancer were explored by function enrichment and pathway analysis.The ROC curve analysis determined a good diagnostic performance of Keapl mRNA for lung squamous cell carcinoma(LUSC),with an area under the ROC curve(AUC)of 0.833,sensitivity of 72.7%,and specificity of 90.6%(P<0.001).Multivariate Cox regression recognized high Keapl mRNA to be an independent risk factor of mortality for overall lung cancer[hazard ratio(HR):11.034,P=0.044],but an independent antagonistic factor for lung adenocarcinoma(LUAD)(HR:0.404,P<0.001).Validation by UALCAN and GEPIA supported Oncomine findings regarding the diagnostic value of Keapl mRNA for LUSC,but denied its prognostic value.After screening,we identified 17 co-expressed genes with both Keapl and Nfe2L2 for LUAD,and 22 for LUSC,mainly enriched in signaling pathway of oxidative stress-induced gene expression via Nrf2.In conclusion,Keapl mRNA has a good diagnostic performance,but controversial prognostic efficacy for LUSC.The pathogenesis of lung cancer is associated with Keapl-Nfe2L2-co-expressed genes by signaling pathway of oxidative stress-induced gene expression via Nrf2.

CRISPR-Cas9-based genome-wide screening identified novel targets for treating sorafenib-resistant hepatocellular carcinoma:a cross-talk between FGF21 and the NRF2 pathway

The treatment of hepatocellular carcinoma(HCC)has been dominated by multikinase inhibitors for more than a decade.However,drug resistance can severely restrict the efficacy of these drugs.Using CRISPR/CAS9 genome library screening,we evaluated Kelch-like ECH-associated protein 1(KEAP1)as a key regulator of sorafenib’s susceptibility in HCC.We also investigated whether KEAP1’s knockdown can stabilize nuclear factor(erythroid-derived 2)-like 2(NRF2)protein levels that led to sorafenib’s resistance,including an NRF2 inhibitor that can synergize with sorafenib to abolish HCC’s growth in vitro and in vivo.Furthermore,we clarified that fibroblast growth factor 21(FGF21)is an important downstream regulator of NRF2 in HCC.Intriguingly,we observed that FGF21 bound to NRF2 through the C-terminus of FGF21,thereby stabilizing NRF2 by reducing its ubiquitination and generating a positive feedback loop in sorafenib-resistant HCC.These findings,therefore,propose that targeting FGF21 is a promising strategy to combat HCC sorafenib’s resistance.