Macrophage senescence in health and diseases

Macrophage senescence,manifested by the special form of durable cell cycle arrest and chronic low-grade inflammation like senescence-associated secretory phenotype,has long been consid-ered harmful.Persistent senescence of macrophages may lead to maladaptation,immune dysfunction,and finally the development of age-related diseases,infections,autoimmune diseases,and malignancies.However,it is a ubiquitous,multi-factorial,and dynamic complex phenomenon that also plays roles in remodeled processes,including wound repair and embryogenesis.In this review,we summarize some general molecular changes and several specific biomarkers during macrophage senescence,which may bring new sight to recognize senescent macrophages in different conditions.Also,we take an in-depth look at the functional changes in senescent macrophages,including metabolism,autophagy,polarization,phagocytosis,antigen presentation,and infiltration or recruitment.Furthermore,some degenerations and diseases associated with senescent macrophages as well as the mechanisms or relevant genetic regulations of senescent macrophages are integrated,not only emphasizing the possibility of regulating macrophage senescence to benefit age-associated diseases but also has an implication on the finding of potential tar-gets ordrugs clinically.

Targeting PI3K/AKT signaling for treatment of idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis(IPF) is a chronic progressive fibrotic interstitial pneumonia with unknown causes. The incidence rate increases year by year and the prognosis is poor without cure.Recently, phosphatidylinositol 3-kinase(PI3 K)/protein kinase B(PKB/AKT) signaling pathway can be considered as a master regulator for IPF. The contribution of the PI3 K/AKT in fibrotic processes is increasingly prominent, with PI3 K/AKT inhibitors currently under clinical evaluation in IPF. Therefore,PI3 K/AKT represents a critical signaling node during fibrogenesis with potential implications for the development of novel anti-fibrotic strategies. This review epitomizes the progress that is being made in understanding the complex interpretation of the cause of IPF, and demonstrates that PI3 K/AKT can directly participate to the greatest extent in the formation of IPF or cooperate with other pathways to promote the development of fibrosis. We further summarize promising PI3 K/AKT inhibitors with IPF treatment benefits, including inhibitors in clinical trials and pre-clinical studies and natural products, and discuss how these inhibitors mitigate fibrotic progression to explore possible potential agents, which will help to develop effective treatment strategies for IPF in the near future.