Objective:To investigate the essential determinants that are critical to initiating the assembly of outer membrane proteins by replacing the POTRA domains of the translocator protein FhaC and the insertase protein TtOmp85 of the Omp85 family. Methods:FhaC, TtOmp85 proteins and their recombinant chimeric proteins after replacing the POTRA domain were obtained by overexpression and purification in vitro. An in vitro reconstitution system was used to investigate the effects of the different domains on the transport efficiency of the substrate outer membrane protein FhaB and the membrane insertion efficiency of OmpA. Results:Replacing the POTRA domain of FhaC with that of TtOmp85 led to the loss of the transport function of FhaB. During the membrane insertion process of OmpA, the FhaC mutant containing the POTRA of TtOmp85 protein acquired the ability to assemble OmpA. Conclusion:The compositional differences in the POTRA domain of Omp85 family proteins determine their abilities to recognize their substrate proteins.

Objective:To investigate the essential determinants that are critical to initiating the assembly of outer membrane proteins by replacing the POTRA domains of the translocator protein FhaC and the insertase protein TtOmp85 of the Omp85 family. Methods:FhaC, TtOmp85 proteins and their recombinant chimeric proteins after replacing the POTRA domain were obtained by overexpression and purification in vitro. An in vitro reconstitution system was used to investigate the effects of the different domains on the transport efficiency of the substrate outer membrane protein FhaB and the membrane insertion efficiency of OmpA. Results:Replacing the POTRA domain of FhaC with that of TtOmp85 led to the loss of the transport function of FhaB. During the membrane insertion process of OmpA, the FhaC mutant containing the POTRA of TtOmp85 protein acquired the ability to assemble OmpA. Conclusion:The compositional differences in the POTRA domain of Omp85 family proteins determine their abilities to recognize their substrate proteins.

Objective:To screen active antibacterial components from licorice extract using BamA and BamD, the core components of Escherichia coli ( E. coli) β-barrel assembly machinery (BAM), as targets in order to combat the increasingly serious problem of antibiotic resistance. Methods:Affinity ultrafiltration combined with high performance liquid chromatography-mass spectrometry (HPLC-MS) was used to screen the potential components interacting with BamA and BamD from licorice extract. Changes in the expression of bamA and bamD genes of E. coli after treatment with the compounds were detected by fluorescence quantitative PCR, and the effects of the compounds on the function of the BAM complex to integrate outer membrane proteins into the bacterial outer membrane were analyzed using an in vitro recombination system. The influence of the compounds on the integrity of bacterial membranes was evaluated through analyzing the accumulation of SDS within the bacterial cells. Results:Bioaffinity ultrafiltration combined with HPLC-MS screening revealed that 18β-glycyrrhetinic acid could interact with BamD. After 18β-glycyrrhetinic acid treatment, the expression of bamA gene increased by 1.5 times, and the expression of bamD gene increased by 2 times. However, the inhibitory effect of 18β-glycyrrhetinic acid on the membrane insertion function of the BAM complex was not observed in the in vitro recombinant system assay, and the cell membrane integrity assay experiments did not reveal any disruption of the E. coli cell membrane by 18β-glycyrrhetinic acid. Conclusions:Using BamA and BamD proteins as targets, a natural product screening method using affinity ultrafiltration combined with HPLC-MS is established. The screening result shows that 18β-glycyrrhetinic acid can interact with BamD and affect the expression of outer membrane proteins in E. coli. Therefore, the screening and experimental procedures established in this study are of good reference value for the screening of novel antimicrobial drugs from other sources targeting outer membrane proteins, and this study also suggests that the selection of the relevant target sites is crucial for the successful screening of the corresponding natural products.

Lung cancer remains the leading cause of cancer deaths worldwide and is the most common cancer in males. Immune-checkpoint inhibitors (ICIs) that target programmed cell death protein-1 (PD-1) or programmed cell death-ligand 1 (PD-L1) have achieved impressive efficacy in the treatment of non-small-cell lung cancer (NSCLC) (Pardoll, 2012; Champiat et al., 2016; Gao et al., 2022). Although ICIs are usually well tolerated, they are often accompanied by immune-related adverse events (irAEs) (Doroshow et al., 2019). Non-specific activation of the immune system produces off-target immune and inflammatory responses that can affect virtually any organ or system (O'Kane et al., 2017; Puzanov et al., 2017). Compared with adverse events caused by chemotherapy, irAEs are often characterized by delayed onset and prolonged duration and can occur in any organ at any stage of treatment, including after cessation of treatment (Puzanov et al., 2017; von Itzstein et al., 2020). They range from rash, pneumonitis, hypothyroidism, enterocolitis, and autoimmune hepatitis to cardiovascular, hematological, renal, neurological, and ophthalmic irAEs (Nishino et al., 2016; Kumar et al., 2017; Song et al., 2020). Hence, we conducted a retrospective study to identify validated factors that could predict the magnitude of the risk of irAEs in patients receiving PD-1/PD-L1 inhibitors; our approach was to analyze the correlation between the clinical characteristics of patients at the start of treatment and relevant indicators such as hematological indices and the risk of developing irAEs. Then, we developed an economical, practical, rapid, and simple model to assess the risk of irAEs in patients receiving ICI treatment, as early as possible.
Male ; Humans ; Carcinoma, Non-Small-Cell Lung/drug therapy* ; Lung Neoplasms/drug therapy* ; Immune Checkpoint Inhibitors/adverse effects* ; Programmed Cell Death 1 Receptor ; Retrospective Studies ; Apoptosis

Ferroptosis is a new programmed cell death characterized by iron dependent and intracellular oxidative accumulation. Current studies have confirmed that ferroptosis is involved in the occurrence and development of neurotoxicity injury, tumors, cardiovascular diseases and other diseases. This paper reviews the mechanisms of ferroptosis and its role in related diseases based on recent studies.

Ferroptosis is a new programmed cell death characterized by iron dependent and intracellular oxidative accumulation. Current studies have confirmed that ferroptosis is involved in the occurrence and development of neurotoxicity injury, tumors, cardiovascular diseases and other diseases. This paper reviews the mechanisms of ferroptosis and its role in related diseases based on recent studies.

Objective: To observe the repairing effect of adipose mesenchymal stem cells (ADSCs) on lung injury induced by silica in rats. Methods: Primary ADSCs-GFP was obtained from rats. ADSCs-GFP was injected into tail vein of silicosis model rats. The expression of green fluorescence in lungs was observed regularly to determine the homing ability of ADSCs. Primary ADSCs of rats were obtained and randomly divided into control group, exposure group, vehicle group and ADSCs group. Silicosis rat model was established by non-exposed tracheal drip method. 24 hours after silica exposure, rats in ADSCs group were injected with ADSCs of 1×10⁶/kg body weight through tail vein, and the pathological changes of lung tissue were observed and evaluated 28 days after intervention. To explore the early intervention mechanism of ADSCs on pulmonary fibrosis in silicosis model rats, apoptosis-related proteins were detected by immunohistochemistry. Results: 28 days after exposure to silica, rats in the exposure group showed obvious pulmonary fibrosis. Compared with exposure group and vehicle group, ADSCs group showed less pulmonary inflammation, less silica nodules and less collagen deposition area. Immunohistochemical results showed that the expression of Caspase-3 and cytochrome C protein decreased and Bcl-2 protein increased after ADSCs transplantation. Conclusion ADSCs infusion has an obvious intervention effect on postponing early silicosis fibrosis in rats exposed to silica, and its mechanism is related to the regulation of apoptotic process.