Astragaloside IV Protects Sepsis-induced Acute Kidney Injury by Attenuating Mitochondrial Dysfunction and Apoptosis in Renal Tubular Epithelial Cells.

BACKGROUND: Acute kidney injury (AKI) is closely linked to the pathogenesis of sepsis. Oxidative stress can affect the development of AKI by increasing damage to renal tubular epithelial cells. Astragaloside IV (AS-IV) is a natural saponin widly verified beneficial for ameliorating sepsis-induced kidney injury. However, the underlying mechanisms of AS-IV on relieving oxidative stress in renal tubular epithelial cells are yet to be established. PURPOSE: We aimed to investigate whether AS-IV could attenuate mitochondrialdysfunction and apoptosis in renal tubular epithelial cells and reveal its underlying mechanisms. METHODS: For the in vivo study, mice were divided into four groups (n=6): sham+saline, CLP+saline, CLP+ASIV- low dosage (5 mg/kg), CLP+AS-IV-high dosage (10 mg/kg), After 6 h or 24 h of treatment, the renal injuries were assessed based on related parameters of blood, protein and histopathological examination. Immunohistochemistry and ELISA were used to examine renal function. The molecular mechanism of AS-IV inhibited apoptosis and mitochondrial damage were monitored by flow cytometry and western blot analysis in HK-2 cells. RESULTS: We found that AS-IV ameliorates renal vacuolization, brush border loss, mitochondrial ultrastructure changes in sepsis-induced AKI, and the apoptosis and oxidative damage were greatly mitigated by AS-IV (10 mg/kg)-treated group. Abnormal changes in mitochondrial morphology and mitochondrial membrane potential were alleviated, and the expression of mitochondrial complex protein I (NDUFB8) and mitochondrial complex protein II (SDHB8) increased with (10 mg/kg)-treated group. Tubular epithelial cell apoptosis in AS-IV (20 µM)-treated cells was reduced by the Bax and cleaved caspase3 pathway. CONCLUSION: These studies demonstrated that AS-IV protects against sepsis-induced kidney tubular injury by alleviating oxidative stress, mitochondrial dysfunction possibly associated with the restored cleaved caspase3 pathway.

Near-infrared photothermal liposomal nanoantagonists for amplified cancer photodynamic therapy.

Photodynamic therapy (PDT) has been demonstrated to be a promising strategy for the treatment of cancer, while its therapeutic efficacy is often compromised due to excessive concentrations of glutathione (GSH) as a reactive oxygen species (ROS) scavenger in cancer cells. Herein, we report the development of near-infrared (NIR) photothermal liposomal nanoantagonists (PLNAs) for amplified PDT through through the reduction of intracellular GSH biosynthesis. Such PLNAs were constructed via encapsulating a photosensitizer, indocyanine green (ICG) and a GSH synthesis antagonist, l-buthionine sulfoximine (BSO) into a thermal responsive liposome. Under NIR laser irradiation at 808 nm, PLNAs generate mild heat via a ICG-mediated photothermal conversion effect, which leads to the destruction of thermal responsive liposomes for a controlled release of BSO in a tumor microenvironment, ultimately reducing GSH levels. This amplifies intracellular oxidative stresses and thus synergizes with PDT to afford an enhanced therapeutic efficacy. Both in vitro and in vivo data verify that PLNA-mediated phototherapy has an at least 2-fold higher efficacy in killing cancer cells and inhibiting tumor growth compared to sole PDT. This study thus demonstrates a NIR photothermal drug delivery nanosystem for amplified photomedicine.