Emodin is a phytochemical with potent anticancer activities against various human malignant cancer types, including lung cancer; however, the molecular mechanisms underlying the effects of emodin remain unclear. In the present study, the A549 and H1299 human non-small lung cancer cell lines were treated with emodin and the induced molecular effects were investigated. Changes in cell viability were evaluated by MTT assay, Hoechst staining was used to indicate the apoptotic cells, and western blotting was utilized to assess endoplasmic reticulum (ER) stress and signaling changes. RNA interference was also employed to further examine the role of tribbles homolog 3 (TRIB3) in the emodin-induced apoptosis of lung cancer cells. Emodin was found to reduce the viability of lung cancer cells and induce apoptosis in a concentration-dependent manner. Emodin-induced apoptosis was impaired by inhibition of ER stress using 4-phenylbutyrate (4-PBA). ER stress and TRIB3/nuclear factor-κB signaling was activated in emodin-treated lung cancer cells. Emodin-induced apoptosis was reduced by TRIB3 knockdown in A549 cells, whereas ER stress was not reduced. In vivo assays verified the significance of these results, revealing that emodin inhibited lung cancer growth and that the inhibitory effects were reduced by inhibition of ER stress with 4-PBA. In conclusion, the results suggest that TRIB3 signaling is associated with emodin-induced ER stress-mediated apoptosis in lung cancer cells.
Objectives. Propofol is a popular anesthetic drug that is neuroprotective. However, the mechanisms of propofol for hippocampal neuroprotection remain elusive. This study is aimed at investigating the neuroprotective effect and mechanism of propofol in hippocampal neurons exposed to ischemia‐reperfusion (I/R) injury. Methods. Hypoxia‐reoxygenated (H/R) HT‐22 cells were used to mimic I/R injury of the hippocampus in vitro. An MTT assay was used to determine cell viability. Cell apoptosis was detected by a TUNEL assay and a flow cytometry cell apoptosis assay. Expression levels of proteins were measured by Western blotting. Intracellular calcium was assessed by Fura‐2/AM staining. Flow cytometry was used to determine the mitochondrial membrane potential (MMP). Coimmunoprecipitation was used to evaluate the stability of the FKBP‐RyR complex. Calcineurin enzymatic activity was measured with a colorimetric method. YAP nuclear translocation was tested by immunofluorescence staining. Results. H/R induced HT‐22 cell viability depression, and apoptosis was reversed by propofol treatment. Propofol could alleviate H/R‐induced intracellular calcium accumulation and MMP loss by inhibiting calcineurin activity and FKBP12.6‐RyR disassociation in a concentration‐dependent manner. In addition, YAP expression was crucial for propofol to protect HT‐22 cell apoptosis from H/R injury. Propofol could activate YAP through dephosphorylation. Activated YAP stimulated the transcription of the Bcl2 gene, which promotes cellular survival. Our data also demonstrated that propofol activated YAP through the RhoA‐Lats1 pathway without large G proteins or MST involvement. In addition, we showed that there was no interaction between calcineurin signaling and YAP activation in HT‐22 cells. Conclusions. Propofol protected hippocampal neurons from I/R injury through two independent signaling pathways, including the calcineurin/FKBP12.6‐RyR/calcium overload pathway and the RhoA/Lats1/YAP/Bcl‐2 pathway.
1 November 2022 in International Journal of Nanomedicine
Background: Compared with traditional drugs, nanomaterial drugs have the benefits of improving the solubility, bioavailability, and absorption rate of insoluble drugs. Nanoporous complexes can increase the efficiency with which drugs can penetrate the blood-brain barrier and reach target organs. Ginsenoside Rg1 is an effective drug that promotes angiogenesis. Ginsenoside Rg1 composite nanoparticles were employed to induce the expression of several key epigenetic enzymes and then activate the VEGF and Notch pathways after the onset of ischemic brain lesions. Methods: We constructed nanoparticles to fully encapsulate the therapeutic drug (ginsenoside Rg1), which can be transferred into brain tissue via the receptor-mediated transfer of drug-encapsulated nanoparticles. Evaluation of the therapeutic effect of ginsenoside Rg1 complex nanovesicles (CNV) was performed by in vitro and in vivo experiments. Real-time polymerase chain reaction (RT- PCR), Western blot, immunohistochemistry staining (IHC), and Co-immunoprecipitation (co-IP) were employed to screen for epigenetic enzymes with an up-regulated expression post ginsenoside Rg1-CNV intervention. RNA sequencing, shRNA knockdown, and chromatin Immunoprecipitation (ChIP) sequencing were performed to detect the target genes of ginsenoside Rg1-CNV that regulate angiogenesis. Then, bioinformatic analysis was performed to investigate the mechanism of action of epigenetic modifying enzymes in regulating target genes. Results: The average of the synthesized ginsenoside Rg1-CNV was 203.78± 6.83 nm, the polydispersion index was 0.135± 0.007, and the Zeta potential was 23.13± 1.65 mV. Through in vivo and in vitro experiments, we found that it promotes the proliferation, migration, and tubular formation of brain microvascular endothelial cells (BMECs). Meanwhile, the intervention of ginsenoside Rg1-CNV promoted the demethylation of H3K27me3 within the promoter region of VEGF-A and Jagged1 genes and reduced the H3K27me3 modification within this region. Conclusion: The ginsenoside Rg1 nanoparticles may be an available blood-brain barrier penetrating agent for ischemic stroke.
1 December 2021 in International Immunopharmacology