Our results demonstrate convergence between AMPK and Nrf2 pathways and this intersection is essential for anti-inflammatory effect of BBR in LPS-stimulated macrophages and endotoxin-shocked mice. Uncovering this intersection is significant for understanding the relationship between energy homeostasis and antioxidative responses and may be beneficial for developing new therapeutic strategies against inflammatory diseases. Antioxid. Redox Signal. 20, 574-588.

Macroautophagy/autophagy has profound implications for aging. However, the true features of autophagy in the progression of aging remain to be clarified. In the present study, we explored the status of autophagic flux during the development of cell senescence induced by oxidative stress. In this system, although autophagic structures increased, the degradation of SQSTM1/p62 protein, the yellow puncta of mRFP-GFP-LC3 fluorescence and the activity of lysosomal proteolytic enzymes all decreased in senescent cells, indicating impaired autophagic flux with lysosomal dysfunction. The influence of autophagy activity on senescence development was confirmed by both positive and negative autophagy modulators; and MTOR-dependent autophagy activators, rapamycin and PP242, efficiently suppressed cellular senescence through a mechanism relevant to restoring autophagic flux. By time-phased treatment of cells with the antioxidant N-acetylcysteine (NAC), the mitochondria uncoupler carbonyl cyanide m-chlorophenyl hydrazone (CCCP) and ambroxol, a reagent with the effect of enhancing lysosomal enzyme maturation, we found that mitochondrial dysfunction plays an initiating role, while lysosomal dysfunction is more directly responsible for autophagy impairment and senescence. Interestingly, the effect of rapamycin on autophagy flux is linked to its role in functional revitalization of both mitochondrial and lysosomal functions. Together, this study demonstrates that autophagy impairment is crucial for oxidative stressinduced cell senescence, thus restoring autophagy activity could be a promising way to retard senescence.

Summary AMPK activation is beneficial for cellular homeostasis and senescence prevention. However, the molecular events involved in AMPK activation are not well defined. In this study, we addressed the mechanism underlying the protective effect of AMPK on oxidative stress‐induced senescence. The results showed that AMPK was inactivated in senescent cells. However, pharmacological activation of AMPK by metformin and berberine significantly prevented the development of senescence and, accordingly, inhibition of AMPK by Compound C was accelerated. Importantly, AMPK activation prevented hydrogen peroxide‐induced impairment of the autophagic flux in senescent cells, evidenced by the decreased p62 degradation, GFP‐RFP‐LC3 cancellation, and activity of lysosomal hydrolases. We also found that AMPK activation restored the NAD + levels in the senescent cells via a mechanism involving mostly the salvage pathway for NAD + synthesis. In addition, the mechanistic relationship of autophagic flux and NAD + synthesis and the involvement of mTOR and Sirt1 activities were assessed. In summary, our results suggest that AMPK prevents oxidative stress‐induced senescence by improving autophagic flux and NAD + homeostasis. This study provides a new insight for exploring the mechanisms of aging, autophagy and NAD + homeostasis, and it is also valuable in the development of innovative strategies to combat aging.

Aging-related, nonresolving inflammation in both the central nervous system (CNS) and periphery predisposes individuals to the development of neurodegenerative disorders (NDDs). Inflammasomes are thought to be especially relevant to immune homeostasis, and their dysregulation contributes to inflammation and NDDs. However, few agents have been clinically shown to reduce NDD incidence by targeting inflammasomes. Our study indicated that NLRP3 (NLR family, pyrin domain containing 3) inflammasome is involved in Parkinson disease (PD) progression in patients and various murine models. In addition, the small molecule kaempferol (Ka) protected mice against LPS-and SNCA-induced neurodegeneration by inhibiting NLRP3 inflammasome activation as evidenced by the fact that Ka reduced cleaved CASP1 expression and disrupted NLRP3-PYCARD-CASP1 complex assembly with concomitant decreased IL1B secretion. Mechanically, Ka promoted macroautophagy/autophagy in microglia, leading to reduced NLRP3 protein expression, which in turn deactivated the NLRP3 inflammasome. Intriguingly, ubiquitination was involved in Ka-induced autophagic NLRP3 degradation. These findings were further confirmed in vivo as knockdown of Atg5 expression or autophagy inhibitor treatment significantly inhibited the Ka-mediated NLRP3 inflammasome inhibition and neurodegeneration amelioration. Thus, we demonstrated that Ka promotes neuroinflammatory inhibition via the cooperation of ubiquitination and autophagy, suggesting that Ka is a promising therapeutic strategy for the treatment of NDDs.

A novel pH sensitive shape‐memory polymer (SMP) is prepared by cross‐linking the β‐cyclodextrin modified alginate (β‐CD‐Alg) and diethylenetriamine modified alginate (DETA‐Alg): The pH reversible β‐CD‐DETA inclusion complexes serve as a reversible phase, and the cross‐linked alginate chains serve as a fixing phase. It is shown that this material can be processed into temporary shape as we needs at pH 11.5 and recover to its initial shape at pH 7. The recovery ratio and the fixity ratio were 95.7 ± 0.9% and 94.8 ± 1.1%, respectively. Furthermore, this material showed good degradability and biocompatibility. Because the shape transition pH value is quite close to that of our body fluid and this pH triggered shape‐memory effect is convenient and safe to use, this material has a high potential for medical application.