The clinical success of immunotherapy that inhibits the negative immune regulatory pathway programmed cell death protein 1/PD-1 ligand (PD-1/PD-L1) has initiated a new era in the treatment of metastatic cancer. PD-L1 expression is upregulated in many solid tumors including lung cancer and functions predominantly in lactate-enriched tumor microenvironments. Here, we provided evidence for PD-L1 induction in response to lactate stimulation in lung cancer cells. Lactate-induced PD-L1 induction was mediated by its receptor GPR81. The silencing of GPR81 signaling in lung cancer cells resulted in a decrease in PD-L1 protein levels and functional inactivation of PD-L1 promoter activity. In addition, GPR81-mediated upregulation of PD-L1 in glucose-stimulated lung cancer cells that recapitulates the enhanced glycolysis in vivo was dependent on lactate dehydrogenase A (LDHA). We also demonstrated that activation of GPR81 decreases intracellular cAMP levels and inhibits protein kinase A (PKA) activity, leading to activation of the transcriptional coactivator TAZ. Interaction of TAZ with the transcription factor TEAD was essential for TAZ activation of PD-L1 and induction of its expression. Furthermore, we found that lactate-induced activation of PD-L1 in tumor cells led to reduced production of interferon-γ and induction of apoptosis of cocultured Jurkat T-cell leukemia cells. Our findings reveal an unexpected role of lactate in contributing to tumor cell protection from cytotoxic T-cell targeting and establishes a direct connection between tumor cell metabolic reprograming and tumor evasion from the immune response.
These findings suggest that isoflurane activates the ER membrane IP3 receptor, producing excessive calcium release and triggering apoptosis. Neurons with enhanced IP3 receptor activity, as in certain cases of familial Alzheimer or Huntington disease, may be especially vulnerable to isoflurane cytotoxicity.
Background We hypothesized that inhalational anesthetics induced cell damage by causing abnormal calcium release from the endoplasmic reticulum via excessive activation of inositol 1,4,5-trisphosphate (IP3) receptors, with isoflurane greater potency than sevoflurane or desflurane. Methods We treated DT40 chicken B lymphocytes with total IP3 receptor knock-out or their corresponding wild type control cells with equipotent exposure of isoflurane, sevoflurane and desflurane. We then determined the degree of cell damage by counting the percentage of annexin V or propidium iodide positively stained cells or measuring caspase-3 activity. We also studied the changes of calcium concentrations in the endoplasmic reticulum, cytosol and mitochondria evoked by equipotent concentrations of isoflurane, sevoflurane and desflurane in both types of DT40 cells. Results Prolonged use of 2 minimal alveolar concentration sevoflurane or desflurane (24 hr) induced significant cell damage only in DT40 Wild type but not IP3 receptor total knock-out cells, but with significantly less potency than isoflurane. In accordance, all three inhalational anesthetics induced significant decrease of calcium concentrations in the endoplasmic reticulum, accompanied with a subsequent significant increase in the cytosol and mitochondrial calcium concentrations only in DT40 wild type but not in IP3 receptor total knock-out cells. Isoflurane treatment showed significantly greater potency of effect than sevoflurane or desflurane. Conclusion Inhalational anesthetics may induce cell damage by causing abnormal calcium release from the endoplasmic reticulum via excessive activation of IP3 receptors. Isoflurane has greater potency than sevoflurane or desflurane to cause calcium release from the endoplasmic reticulum and to induce cell damage.
MRS 1292 inhibits A3AR-mediated shrinkage of human NPE cells and reduces mouse IOP, consistent with its putative action as a cross-species A3 antagonist.
Epithelial-mesenchymal transition (EMT) plays a fundamental role in cancer metastasis. The ubiquitin ligase FBXW7, a general tumor suppressor in human cancer, has been implicated in diverse cellular processes, however, its role in cholangiocarcinoma (CCA) metastasis has not been identified. Here, we report a crucial role of FBXW7 in CCA metastasis by regulating EMT. Loss of FBXW7 expression was detected in CCA cells and clinical specimens. Clinicopathological analysis revealed a close correlation between FBXW7 deficiency and metastasis, TNM stage and differentiation in intrahepatic CCA and perihilar CCA. Moreover, FBXW7 silencing in CCA cells dramatically promoted EMT, stem-like capacity and metastasis both in vitro and in vivo. Conversely, FBXW7 overexpression attenuated these processes. Mechanistically, treatment with rapamycin, a mTOR inhibitor, inhibited EMT, stem-like capacity and metastasis induced by FBXW7 silencing both in vitro and in vivo. Furthermore, the expression of EMT regulating transcription factors, snail, slug and ZEB1, were also decreased markedly with rapamycin treatment. In addition, silencing ZEB1 inhibited EMT and metastasis of both CCA cells and FBXW7 deficient CCA cells, which implicated the potential role of ZEB1 in FBXW7/mTOR signaling pathway related CCA metastasis. In conclusion, our findings defined a pivotal function of FBXW7 in CCA metastasis by regulating EMT.
The platform consists of three modules, which are pre‐configured bioinformatic pipelines, cloud toolsets, and online omics' courses. The pre‐configured bioinformatic pipelines not only combine analytic tools for metagenomics, genomes, transcriptome, proteomics and metabolomics, but also provide users with powerful and convenient interactive analysis reports, which allow them to analyze and mine data independently. As a useful supplement to the bioinformatics pipelines, a wide range of cloud toolsets can further meet the needs of users for daily biological data processing, statistics, and visualization. The rich online courses of multi‐omics also provide a state‐of‐art platform to researchers in interactive communication and knowledge sharing.
The commonly used inhaled anesthetic isoflurane has been shown to be both neuroprotective and neurotoxic in various cell cultures and animal models. We hypothesize that, like cerebral ischemia, isoflurane is inherently neurotoxic. Limited exposure of isoflurane provides neuroprotection via induction of endogenous neuroprotective mechanisms (preconditioning), while prolonged exposure of isoflurane induces neurotoxicity directly by its inherent neurotoxic effects. To test this hypothesis, we treated rat primary cortical neurons at different days in vitro (DIV) and rat pheochromocytoma neurosecretory (PC12) cells with or without Alzheimer's mutated presenilin-1 (PS1) with 2.4% isoflurane for 24 h to induce cell damage determined by both MTT (3-(4,5-dimethyithiazol-2-yl)-2,5-diphenyl-tetrazolium bromide) reduction and LDH (lactate dehydrogenase) release assays. For isoflurane preconditioning, we treated the above cells with isoflurane at 0.6%, 1.2% and 2.4% for 60 min, 4 h prior to a prolonged exposure of 2.4% isoflurane for 24 h. One hour of preconditioning with isoflurane dose-dependently inhibited neurotoxicity induced by 2.4% isoflurane for 24 h in both primary cortical neurons and PC12 cells. This neuroprotection was most dramatically observed in matured cortical neurons (DIV 16) and PC12 cells with over expression of Alzheimer's mutated PS1 (L286V). Preconditioning L286V PC12 cells with equivalent two minimal alveolar concentrations (MAC) of halothane (1.5%), but not sevoflurane (4%), also abolished the neurotoxicity induced by 2.4% isoflurane for 24 h. Overall, these results suggest that isoflurane may be both neuroprotective and neurotoxic, depending on the exposure concentrations and duration.
Cancer-induced bone pain (CIBP) is a common clinical problem in breast cancer patients with bone metastasis. Recent studies shows chemokines are novel targets for treatment of CIBP. In this study, we intra-tibial inoculated with Walker 256 rat mammary gland carcinoma cells into rat bone to established metastatic breast cancer. Then we measured the expression of CXCL10 in the spinal cord of metastatic bone cancer rats, investigated the role of CXCL10 in the development of CIBP, and the underlying mechanism. Results revealed that after intra-tibial inoculation with Walker 256 cells, rats showed up-regulation of CXCL10 and its receptor CXCR3 in the spinal cord. Interestingly, intrathecally injection of recombinant CXCL10 protein induced mechanical allodynia in naïve rats. Blocking the function of CXCL10/CXCR3 pathway via anti-CXCL10 antibody or CXCR3 antagonist prevented the development of CIBP and microglial activation. Moreover, CXCL10-induced mechanical allodynia was rescued by minocycline treatment during the late-stage of CIBP, days 10-14. The regulation of CXCL10 expression involved microglial activation in a manner of autocrine positive feedback. These results suggest that CXCL10 may be a necessary algogenic molecule, especially in the development of CIBP. Its function was partly mediated via spinal microglial activation. This study provides a novel insight into the biological function of chemokine CXCL10 in the molecular mechanism underlying cancer pain. It also provides new target for clinical treatment of metastatic breast cancer-induced bone pain in future.
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