Construction of robust protein nanocage by designed disulfide bonds for active cargo molecules protection in the gastric environment.

Notwithstanding the progress made, cargo molecules encapsulated within ferritin via oral administration in the gastric environment remains a persistent challenge. This study focuses on the strategic enhancement of ferritin stability in harsh gastric environment. By taking advantagie of computational-assisted design, we strategically introduced up to 96 disulfide bonds along three key inter-subunit interfaces to one single ferritin molecule with human H-chain ferritin and shrimp (Marsupenaeus japonicus) ferritin as starting materials, producing two kinds of robust ferritin nanocages with markedly enhanced acid and protease (pepsin and rennin) resistance. The crystal structure of ferritin nanocage confirmed our design at an atomic level. Encapsulation experiments demonstrated successful loading of bioactive cargo molecules (e.g., doxorubicin) into the engineered ferritin nanocages, with pronouncedly improved protection against leakage under acidic condition and the presence of pepsin and rennin as compared to their native counterparts. This study presents a potential approach for the design and engineering of protein nanocages for oral administration.

Emodin activates autophagy to suppress oxidative stress and pyroptosis via mTOR-ULK1 signaling pathway and promotes multi-territory perforator flap survival.

BACKGROUND: Multi-territory perforator flap reconstruction has been proven effective in treating large skin and soft tissue defects in clinical settings. However, in view of that the multi-territory perforator flap is prone to partial postoperative necrosis, increasing its survival is the key to the success of reconstruction. In this study, we aimed to clarify the effect of emodin on multi-territory perforator flap survival. METHODS: Flap survival was assessed by viability area analysis, infrared laser imaging detector, HE staining, immunohistochemistry, and angiography. Western blotting, immunofluorescence assays, and real-time fluorescent quantitative PCR were performed to detect the indicators of oxidative stress, pyroptosis and autophagy. RESULTS: After emodin treatment, the multi-territory perforator flap showed a significantly increased survival rate, which was shown to be closely related to the inhibition of oxidative stress and pyroptosis and enhanced autophagy. Meanwhile, the use of autophagy inhibitor 3 MA was found to reverse the inhibitory effects of emodin on oxidative stress and pyroptosis and weaken the improving effect of emodin on flap survival, suggesting that autophagy plays a critical role in emodin-treated flaps. Interestingly, our mechanistic investigations revealed that the positive effect of emodin on multi-territory perforator flap was attributed to the mTOR-ULK1 signaling pathway activation. CONCLUSIONS: Emodin can inhibit oxidative stress and pyroptosis by activating autophagy via the mTOR-ULK1 pathway, thereby improving the multi-territory perforator flap survival.

[Comparative study on distribution of endophytic fungi in Eucommia barks from different habitats].

A total of 152 strains of endophytic fungi were isolated from the barks of Eucommia ulmoides in three regions (Lueyang country, Zunyi country, Cili country). Based on morphological characteristics and analysis of ITS sequences, these strains were identified into 8 genera. Thereinto Phomopsis, Diaporthe and Alternaria were common genera to Eucommia barks from different sites. But the dominant genus was different: Alternaria was the dominant genus in the barks from Cili country, and Phomopsis was the dominant genus from Zunyi country, then Diaporthe was the one from Lueyang country. According to the similarity coefficient, the composition of the endophytic fungi was distinctly different between the barks from three sites. The diversity and species richness in Lueyang country and Cili country were found higher than those in Zunyi country. The evenness of endophytic fungi was 0.936 5 in Lueyang county, which was higher than 0.737 1 or 0.641 0 in Cili county or Zunyi county, respectively. After phylogenic analysis and calculating the genetic distances of typical strains belong to Phomopsis and its perfect stage--Diaporthe, there was very high genetic diversity in the two genera from our study. In conclusion, the community structure and diversity of endophytic fungi were significant different in Eucommia barks from the three habitats.