Objective To systematically assess the spatiotemporal distribution,risk factors,and future trends of chronic obstructive pulmonary disease(COPD)among individuals under 50 years of age globally from 1990 to 2021 based on Global Burden of Disease(GBD)data in order to provide support for the formulation of prevention and control strategies of the disease.Methods The GBD data from 1990 to 2021 were analyzed for the incidence,mortality,disability-adjusted life years(DALYs),and estimated annual percentage change(EAPC)of COPD in<50-year-old individuals across 204 countries and regions.The data were stratified by age,sex,region,country,and sociodemographic index(SDI).The COPD trends until 2035 were predicted.Results In 2021,the global incidence of early-onset COPD was estimated at 2.5 million cases(95%uncertainty interval:2.09～2.96 million),representing a 50.55%increase compared to 1990.Significant regional heterogeneity was observed,with low SDI regions experiencing a 134.08%increase,whereas high SDI regions exhibited a rise-then-fall trend.Risk factor analysis identified environmental and occupational exposures(air pollution,ambient ozone pollution,household air pollution from solid fuels,etc.)and smoking as the primary etiological factors.Notably,household solid fuel exposure accounted for 50.90%of COPD-related deaths in low SDI regions,compared to only 0.03%in high SDI regions.Projections indicated that by 2035,the global burden of early-onset COPD will increase to 2.59 million cases.Conclusion The global disease burden of COPD among people under 50 years increased significantly from 1990 to 2021,with pronounced disparities across regions and socioeconomic levels.COPD deaths in low-SDI regions are strongly associated with solid fuel exposure and particulate matter pollution,and these regions are expected to remain the main drivers of global COPD incidence growth through 2035.

Aim Toclarifytheeffectofacteosideon proliferation of neural stem cells (NSCs ) from adult mice,as well as the involved signaling pathway.Meth-ods NSCswereisolatedfromthesubventricularzone (SVZ)of adult C57BL/6 mice,then identified by im-munofluorescence staining with Nestin,the marker of NSCs.NSCs were exposed to acteoside (5,10,20,40μmol·L-1 )in absence of mitogen(EGF/bFGF)for 24 h.We employed CCK8 assay to detect NSCs viability and BrdU staining to identify NSCs proliferation.We performed Western blot to quantify the expression level ofp-AktinducedbyacteosideonNSCs.Results With-out mitogen,acteoside increased NSCs proliferation by activating p-Akt,which can be blocked by LY294002, the inhibitor of PI3K/AKT signaling pathway.Conclu-sion ActeosidepromotestheproliferationofNSCsfrom adult mice by activating PI3K/AKT pathway.