Evaluating toxicity and decoding the underlying mechanisms of active compounds are crucial for drug development. In this study, we present an innovative, integrated approach that combines air flow-assisted desorption electrospray ionization mass spectrometry imaging (AFADESI-MSI), time-of-flight secondary ion mass spectrometry (ToF-SIMS), and spatial metabolomics to comprehensively investigate the nephrotoxicity and underlying mechanisms of nitidine chloride (NC), a promising anti-tumor drug candidate. Our quantitive AFADESI-MSI analysis unveiled the region specific of accumulation of NC in the kidney, particularly within the inner cortex (IC) region, following single and repeated dose of NC. High spatial resolution ToF-SIMS analysis further allowed us to precisely map the localization of NC within the renal tubule. Employing spatial metabolomics based on AFADESI-MSI, we identified over 70 discriminating endogenous metabolites associated with chronic NC exposure. These findings suggest the renal tubule as the primary target of NC toxicity and implicate renal transporters (organic cation transporters, multidrug and toxin extrusion, organic cation transporter 2), metabolic enzymes (protein arginine N-methyltransferase, nitric oxide synthase), mitochondria, oxidative stress, and inflammation in NC-induced nephrotoxicity. This study offers novel insights into NC-induced renal damage, representing a crucial step towards devising strategies to mitigate renal damage caused by this compound.
The conversion of tumor-associated macrophages (TAMs) from M2 phenotype to M1 phenotype could reverse the immunosuppression associated with the tumor microenvironment. Here, we constructed M2 phenotype macrophage-targeted Lipo@CpG-FA by encapsulating CpG ODNs. The combination of Lipo@CpG-FA with FA-Lipo@Ele-AS1411 caused regression and inhibition of 4T1 breast cancers by reversing the M2-TAMs mediated immunosuppression and efficiently inducing effector T cell activation in the tumor microenvironment. In addition to antitumor effects, Elemene (Ele) could inhibit the effect M2 macrophage proliferation by enhancing the therapeutic effects. The application of this strategy may be potentially expanded for cancer therapy in combination with other therapeutics.
Inhibiting the death receptor 3 (DR3) signaling pathway in group 3 innate lymphoid cells (ILC3s) presents a promising approach for promoting mucosal repair in individuals with ulcerative colitis (UC). Paeoniflorin, a prominent component of Paeonia lactiflora Pall., has demonstrated the ability to restore barrier function in UC mice, but the precise mechanism remains unclear. In this study, we aimed to delve into whether paeoniflorin may promote intestinal mucosal repair in chronic colitis by inhibiting DR3 signaling in ILC3s. C57BL/6 mice were subjected to random allocation into 7 distinct groups, namely the control group, the 2% dextran sodium sulfate (DSS) group, the paeoniflorin groups (25, 50, and 100 mg/kg), the anti-tumor necrosis factor-like ligand 1A (anti-TL1A) antibody group, and the IgG group. We detected the expression of DR3 signaling pathway proteins and the proportion of ILC3s in the mouse colon using western blot and flow cytometry, respectively. Meanwhile, DR3-overexpressing MNK-3 cells and 2% DSS-induced Rag1-/- mice were used for verification. The results showed that paeoniflorin alleviated DSS-induced chronic colitis and repaired the intestinal mucosal barrier. Simultaneously, paeoniflorin inhibited the DR3 signaling pathway in ILC3s and regulated the content of cytokines (Interleukin-17A, Granulocyte-macrophage colony stimulating factor, and Interleukin-22). Alternatively, paeoniflorin directly inhibited the DR3 signaling pathway in ILC3s to repair mucosal damage independently of the adaptive immune system. We additionally confirmed that paeoniflorin-conditioned medium (CM) restored the expression of tight junctions in Caco-2 cells via coculture. In conclusion, paeoniflorin ameliorates chronic colitis by enhancing the intestinal barrier in an ILC3-dependent manner, and its mechanism is associated with the inhibition of the DR3 signaling pathway.
In our prior research, polymer nanoparticles containing tobramycin displayed robust antibacterial efficacy against biofilm-embedded Pseudomonas aeruginosa and Burkholderia cenocepacia cells, critical pathogens in cystic fibrosis. In the current study, we investigated the deposition of a nanoparticulate carrier composed of poly(D,L-lactic-co-glycolic acid) (PLGA) and poly(ethylene glycol)-block-PLGA (PEG-PLGA) that was either covalently bonded with cyanine-5-amine or noncovalently bound with freely embedded cationic rhodamine B, which served as a drug surrogate. After exposing these nanoparticles to bacteria, we performed cell fractionation and fluorescence analysis, which highlighted the accumulation of cyanine-5-amine in the outer membranes and the accumulation of rhodamine B in the cytoplasm of cells. The results indicated that these organic nanoparticles are effective vehicles for targeted antibiotic delivery in bacterial cells, explaining the observed increase in the efficacy of encapsulated tobramycin against biofilms. This work emphasizes the potential of PEG-PLGA-based formulations for advanced drug delivery strategies.