Pyroptosis, a form of programmed cell death (PCD), has garnered increasing attention as it relates to innate immunity and diseases. However, the involvement of pyroptosis in the mechanism by which lobaplatin acts against colorectal cancer (CRC) is unclear. Our study revealed that treatment with lobaplatin reduced the viability of HT-29 and HCT116 cells in a dose-dependent manner. Morphologically, HT-29 and HCT116 cells treated with lobaplatin exhibited microscopic features of cell swelling and large bubbles emerging from the plasma membrane, and transmission electron microscopy (TEM) revealed multiple pores in the membrane. GSDME, rather than GSDMD, was cleaved in lobaplatin-induced pyroptosis in HT-29 and HCT116 cells due to caspase-3 activation. Knocking out GSDME switched lobaplatin-induced cell death from pyroptosis to apoptosis but did not affect lobaplatin-mediated inhibition of growth and tumour formation of HT-29 and HCT116 cells in vivo and in vitro. Further investigation indicates that lobaplatin induced reactive oxygen species (ROS) elevation and JNK phosphorylation. NAC, a ROS scavenger, completely reversed the pyroptosis of lobaplatin-treated HT-29 and HCT116 and JNK phosphorylation. Activated JNK recruited Bax to mitochondria, and thereby stimulated cytochrome c release to cytosol, followed by caspase-3/-9 cleavage and pyroptosis induction. Therefore, in colon cancer cells, GSDME mediates lobaplatin-induced pyroptosis downstream of the ROS/JNK/Bax-mitochondrial apoptotic pathway and caspase-3/-9 activation. Our study indicated that GSDME-dependent pyroptosis is an unrecognized mechanism by which lobaplatin eradicates neoplastic cells, which may have important implications for the clinical application of anticancer therapeutics.

Glial glutamate transporter-1 (GLT-1) plays an essential role in removing glutamate from the extracellular space and maintaining the glutamate below neurotoxic level in the brain. To explore whether GLT-1 plays a role in the acquisition of brain ischemic tolerance (BIT) induced by cerebral ischemic preconditioning (CIP), the present study was undertaken to observe in vivo changes in the expression of GLT-1 and glial fibrillary acidic protein (GFAP) in the CA1 hippocampus during the induction of BIT, and the effect of dihydrokainate (DHK), an inhibitor of GLT-1, on the acquisition of BIT in rats. Immunohistochemistry for GFAP showed that the processes of astrocytes were prolonged after a CIP 2 days before the lethal ischemic insult, which could protect pyramidal neurons in the CA1 hippocampus against delayed neuronal death induced normally by lethal ischemic insult. The prolonged processes extended into the area between the pyramidal neurons and tightly surrounded them. These changes made the pyramidal layer look like a 'shape grid'. Simultaneously, the prolonged and extended processes showed a great deal of GLT-1. Western blotting analysis showed significant upregulation of GLT-1 expression after the CIP, especially when it was administered 2 days before the subsequent lethal ischemic insult. Neuropathological evaluation by thionin staining showed that DHK dose-dependently blocked the protective role of CIP against delayed neuronal death induced normally by lethal brain ischemia. It might be concluded that the surrounding of pyramidal neurons by astrocytes and upregulation of GLT-1 induced by CIP played an important role in the acquisition of the BIT induced by CIP.

Bile acids serve a critical role in the induction of gastric intestinal metaplasia (IM) and gastric carcinogenesis. The present study investigated the effects of bile acids on the induction of gastric IM formation. The results demonstrated that the expression levels of caudal-related homeobox transcription factor 2 (CDX2), mucin 2 (MUC2) and farnesoid X receptor (FXR) were increased in vitro and in vivo following treatment with bile acids, and CDX2 transcriptionally activated MUC2 expression. Furthermore, knockdown of FXR attenuated bile acid-enhanced CDX2 promoter activity and protein expression. Conversely, the FXR agonist GW4064 synergistically enhanced bile acid-induced CDX2 promoter activity. Bile acid treatment led to an increase in nuclear factor (NF)-κB activity and protein expression. Treatment with GW4064 or the FXR antagonist Z-guggulsterone enhanced or attenuated bile acid-induced NF-κB activity, respectively. In addition, quantitative chromatin immunoprecipitation confirmed that bile acids led to enhanced binding of p50 to the CDX2 promoter, whereas this effect was not observed for p65. Treatment with GW4064 or Z-guggulsterone enhanced and attenuated the binding activity of p50 to the CDX2 promoter, respectively. These results indicated that bile acids may activate the FXR/NF-κB signalling pathway, thereby upregulating CDX2 and MUC2 expression in normal gastric epithelial cells.

BackgroundThere is no highly effective chemotherapy for malignant gliomas to date. We found that dimethylaminomicheliolide (DMAMCL), a selective inhibitor of acute myeloid leukemia (AML) stem/progenitor cells, inhibited the growth of glioma cells.MethodsThe distribution of DMAMCL in brain was analyzed by an ultraperformance liquid chromatography-mass spectrometry (UPLC-MS/MS) system. The anti-tumor evaluations of DMAMCL in vitro were performed by MTT, FACS and RT-PCR. In vivo, the mixture of C6 cells and matrigel was injected into caudatum, and the anti-tumor activity of DMAMCL was evaluated by tumor growth and rat survival. The toxicity of DMAMCL was evaluated by body weight, daily food intake, hematological or serum biochemical analyses, and histological appearance of tissues.ResultsThe IC50 values of DMAMCL against the C6 and U-87MG cell lines in vitro were 27.18 ± 1.89 μM and 20.58 ± 1.61 μM, respectively. DAMMCL down-regulated the anti-apoptosis gene Bcl-2 and increased apoptosis in C6 and U-87MG cells in a dose-dependent manner. In a C6 rat tumor model, daily administration of DMAMCL for 21 days reduced the burden of C6 tumors by 60% to 88% compared to controls, and more than doubled the mean lifespan of tumor-bearing rats. Distribution analysis showed that the DMAMCL concentration was higher in the brain than in plasma. Evaluations for toxicity revealed that oral administration of DMAMCL at 200 or 300 mg/kg once a day for 21 days did not result in toxicity.ConclusionsThese results suggest that DMAMCL is highly promising for the treatment of glioma.

Aims Findings from our laboratory indicate that proinflammatory cytokines and their transcription factor, nuclear factor-kappaB (NF-κB), are increased in the hypothalamic paraventricular nucleus (PVN) and contribute towards the progression of heart failure. In this study, we determined whether NF-κB activation within the PVN contributes to sympathoexcitation via interaction with neurotransmitters in the PVN during the pathogenesis of heart failure. Methods and results Heart failure was induced in rats by left anterior descending coronary artery ligation. Sham-operated control (SHAM) or heart failure rats were treated for 4 weeks through bilateral PVN infusion with SN50, SN50M or vehicle via osmotic minipump. Rats with heart failure treated with PVN vehicle or SN50M (inactive peptide for SN50) had increased levels of glutamate, norepinephrine, tyrosine hydroxylase (TH), superoxide, gp91phox (a subunit of NAD(P)H oxidase), phosphorylated IKKβ and NF-κB p65 activity, and lower levels of gamma-aminobutyric acid (GABA) and the 67-kDa isoform of glutamate decarboxylase (GAD67) in the PVN compared with those of SHAM rats. Plasma levels of cytokines, norepinephrine, epinephrine and angiotensin II, and renal sympathetic nerve activity (RSNA) were increased in heart failure rats. Bilateral PVN infusion of SN50 prevented, the decreases in PVN GABA and GAD67, and the increases in RSNA and PVN glutamate, norepinephrine, TH, superoxide, gp91phox, phosphorylated IKKβ and NF-κB p65 activity observed in vehicle or SN50M treated heart failure rats. A same dose of SN50 given intraperitoneally did not affect neurotransmitters concentration in the PVN and was similar to vehicle treated heart failure rats. Conclusion These findings suggest that NF-κB activation in the PVN modulates neurotransmitters and contributes to sympathoexcitation in rats with ischemia-induced heart failure.