Metformin promotes anti-tumor immunity in STK11 mutant NSCLC through AXIN1-dependent upregulation of multiple nucleotide metabolites

Background:Metformin has pleiotropic effects beyond glucose reduction,including tumor inhibition and immune regulation.It enhanced the anti-tumor effects of programmed cell death protein 1(PD-1)inhibitors in serine/threonine kinase 11(STK11)mutant non-small cell lung cancer(NSCLC)through an axis inhibition protein 1(AXIN1)-dependent manner.However,the alterations of tumor metabolism and metabolites upon metformin administration remain unclear.Methods:We performed untargeted metabolomics using liquid chromatography(LC)-mass spectrometry(MS)/MS system and conducted cell experiments to verify the results of bioinformatics analysis.Results:According to the Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway database,most metabolites were annotated into metabolism,including nucleotide metabolism.Next,the differentially expressed metabolites in H460(refers to H460 cells),H460_met(refers to metformin-treated H460 cells),and H460_KO_met(refers to metformin-treated Axin1-/-H460 cells)were distributed into six clusters based on expression patterns.The clusters with a reversed expression pattern upon metformin treatment were selected for further analysis.We screened out metabolic pathways through KEGG pathway enrichment analysis and found that multiple nucleotide metabolites enriched in this pathway were upregulated.Furthermore,these metabolites enhanced the cytotoxicity of activated T cells on H460 cells in vitro and can activate the stimulator of the interferon genes(STING)pathway independently of AXIN1.Conclusion:Relying on AXIN1,metformin upregulated multiple nucleotide metabolites which promoted STING signaling and the killing of activated T cells in STK11 mutant NSCLC,indicating a potential immunotherapeutic strategy for STK11 mutant NSCLC.

Electrotaxis of alveolar epithelial cells in direct-current electric fields

Purpose:This study aims to elucidate the electrotaxis response of alveolar epithelial cells(AECs)in direct-current electric fields(EFs),explore the impact of EFs on the cell fate of AECs,and lay the foundation for future exploitation of EFs for the treatment of acute lung injury.Methods:AECs were extracted from rat lung tissues using magnetic-activated cell sorting.To elucidate the electrotaxis responses of AECs,different voltages of EFs(0,50,100,and 200 mV/mm)were applied to two types of AECs,respectively.Cell migrations were recorded and trajectories were pooled to better demonstrate cellular activities through graphs.Cell directionality was calculated as the cosine value of the angle formed by the EF vector and cell migration.To further demonstrate the impact of EFs on the pulmonary tissue,the human bronchial epithelial cells transformed with Ad12-SV402B(BEAS-2B cells)were obtained and experimented under the same conditions as AECs.To determine the influence on cell fate,cells underwent electric stimulation were collected to perform Western blot analysis.Results:The successful separation and culturing of AECs were confirmed through immunofluorescence staining.Compared with the control,AECs in EFs demonstrated a significant directionality in a voltage-dependent way.In general,type I alveolar epithelial cells migrated faster than type II alveolar epithelial cells,and under EFs,these two types of cells exhibited different response threshold.For type II alveolar epithelial cells,only EFs at 200 mV/mm resulted a significant difference to the velocity,whereas for,EFs at both 100 mV/mm and 200 mV/mm gave rise to a significant difference.Western blotting suggested that EFs led to an increased expression of a AKT and myeloid leukemia 1 and a decreased expression of Bcl-2-associated X protein and Bcl-2-like protein 11.Conclusion:EFs could guide and accelerate the directional migration of AECs and exert antiapoptotic effects,which indicated that EFs are important biophysical signals in the re-epithelialization of alveolar epithelium in lung injury.

Estimating global prevalence,incidence,and outcomes of nonalcoholic fatty liver disease from 2000 to 2021:systematic review and meta-analysis

Background:The increasing burden of non-alcoholic fatty liver disease(NAFLD)worldwide imposes an emerging public health issue.We perform the current study to estimate the global prevalence,incidence,disease progression,and clinical outcomes of NAFLD.Methods:A systematic search was conducted in Medline,Embase,Web of Science,Google Scholar,and Cochrane CENTRAL that screened articles in English language published from January 2000 to December 2021.NAFLD prevalence,incidence,rate of disease progression,and outcomes were calculated with the DerSimonian-Laird random effects model with arcsine transformation.Results:Our search identified 59,156 records,of which 578 studies fulfilled our inclusion criteria.The overall prevalence of NAFLD was 29.38%(95%confidence interval[CI]28.09-30.69)regardless of the diagnostic techniques.Looking at the group in which the diagnosis was made by ultrasound exclusively,the pooled prevalence was 30.49%(95%CI 29.55-31.43).NAFLD has become more prevalent during the year 2011-2021(31.63%,95%CI 30.23-33.04)compared with year 2000-2010(27.94%,95%CI 26.23-29.69).The pooled estimation of non-alcoholic steatohepatitis prevalence was 8.26%(95%CI 1.13-21.01),46.49%(95%CI 35.93-57.20),and 46.72%(95%CI 37.57-55.98)in general population,NAFLD patients,and severe/morbidly obese patients,respectively.Based on a total of 110,142 newly developed NAFLD patients,the pooled incident rate was estimated as 46.24 cases per 1000 person-years(95%CI 43.21-49.30).In patients with NAFLD,the incident rate of hepatocellular carcinoma was 1.46(95%CI 0.90-2.03)cases per 1000 person-years.The overall pooled estimate of NAFLD related mortality was 23.91(95%CI 13.55-37.18)death per 1000 person-years.Conclusions:The prevalence of NAFLD is increasing globally.It is contributing to poor clinical outcomes including hepatocellular carcinoma and death.Rising awareness and urgent actions are warranted to control the NAFLD pandemic across the globe.Registration:PROSPERO,No.CRD42020171104.