STING1 in sepsis: Mechanisms, functions, and implications / 中华创伤杂志(英文版)

Sepsis is a life-threatening clinical syndrome and one of the most challenging health problems in the world. Pathologically, sepsis and septic shock are caused by a dysregulated host immune response to infection, which can eventually lead to multiple organ failure and even death. As an adaptor transporter between the endoplasmic reticulum and Golgi apparatus, stimulator of interferon response cGAMP interactor 1 (STING1, also known as STING or TMEM173) has been found to play a vital role at the intersection of innate immunity, inflammation, autophagy, and cell death in response to invading microbial pathogens or endogenous host damage. There is ample evidence that impaired STING1, through its immune and non-immune functions, is involved in the pathological process of sepsis. In this review, we discuss the regulation and function of the STING1 pathway in sepsis and highlight it as a suitable drug target for the treatment of lethal infection.

Enhancive effect of HMGB1 gene silence on adriamycin-induced apoptosis in K562/A02 drug resistance leukemia cells / 中华血液学杂志

<p><b>OBJECTIVE</b>To investigate the effect of high mobility group boxl (HMGBI) gene silence on adriamycin (ADM)-induced apoptosis in K562/A02 drug resistance leukemia cells.</p><p><b>METHODS</b>K562/ A02 cells were transient transfected with HMGB1- small interference RNA(siRNA) vector, and the levels of HMGB1 gene differential expression pre-and post-transfection were measured by RT-PCR and Western blotting. 50% inhibition concentration (IC50) of ADM on K562/A02 was determined by WST-8 assay. Cell apoptosis was assessed by flow cytometry. The release of Smac/DIABLO from the mitochondria to the cytoplasm was assayed by Western blotting. Activity of Caspase-3 was assayed with a Caspase Colorimetric Assay Kit.</p><p><b>RESULTS</b>(1) The HMGB1 expression at mRNA and protein levels in HMGB1 siRNA transfected K562/A02 cells were decreased by 86% and 71% respectively compared with control. (2) Suppression of HMGB1 by siRNA in K562/A02 cells resulted in a reversal of the resistance to ADM, and decreased IC50 from (4.83 +/- 0.08) microg/ml to (1.33 +/- 0.10) microg/ml. 1 microg/ml and 5 microg/ml of ADM treatment increased cell apoptotic rate by 27% and 32% respectively. (3) HMGB1 suppression in K562/A02 cells significantly promoted ADM- induced Smac/DIABLO release from the mitochondria to the cytoplasm, and increased the activities of Caspase-3.</p><p><b>CONCLUSION</b>HMGB1 gene silence can enhance sensitivity of K562/A02 cells to ADM and reverse cell resistant to ADM.</p>

High mobility group box 1 is increased in children with acute lymphocytic leukemia and stimulates the release of tumor necrosis factor-alpha in leukemic cell / 中华儿科杂志

<p><b>OBJECTIVE</b>Cytokine mediated cell immunity is the main mode of anti-tumor immunity in organism, and the disequilibrium of cytokine network is the main cause of tumor cells escaping immunologic surveillance. High mobility group box 1 (HMGB1), a nuclear protein, has recently been identified as an important mediator of local and systemic inflammatory diseases when released into the extracellular milieu. In the present study, the investigators explored the clinical significance of alteration in the serum levels of HMGB1 in childhood acute lymphocytic leukemia (ALL) and the mechanism of HMGB1-induced tumor necrosis factor (TNF)-alpha secretion in leukemic cells.</p><p><b>METHODS</b>The serum levels of HMGB1 in healthy children and childhood ALL were assayed by Western blotting. K562 leukemic cells were stimulated with recombinant HMGB1 protein in vitro, and the secretion of TNF-alpha was determined by using ELISA. The effects of HMGB1 on activation of p38, c-Jun amino-terminal kinase (JNK), and extracellular-signal regulated protein kinase (ERK) and mitogen-activated protein kinase (MAPK) in K562 cells were assayed by using Western blotting. The effects of inhibitors specific for the MAPK on HMGB1-induced TNF-alpha secretion were assayed by using ELISA.</p><p><b>RESULTS</b>The serum levels of HMGB1 were significantly higher in ALL initial treatment group (n = 15, 43.78 +/- 4.62 microg/ml) than those in healthy control group (n = 15, 0.60 +/- 0.48 microg/ml, P < 0.01) and ALL complete remission group (n = 15, 0.89 +/- 0.62 microg/ml, P < 0.01). No significant difference was found between the healthy control group and ALL complete remission group in HMGB1 levels (P > 0.05). TNF-alpha started to become detectable at 2 h and was still increasing at 16 h after HMGB1 (1 microg/ml) treatment in K562 cell culture. TNF-alpha was also secreted from K562 cells in a dose-dependent manner after HMGB1 (1 ng/ml-1 microg/ml) exposure. HMGB1 induced the phosphorylation of p38, JNK and ERK in k562 cells. Inhibitors specific for the JNK (SP600125), MEK (PD98059), and p38 MAPK (SB203580), abrogated HMGB1-induced TNF-alpha secretion.</p><p><b>CONCLUSIONS</b>The measurement of serum HMGB1 is helpful to evaluate the prognosis of the childhood ALL. HMGB1 stimulates leukemic cells to secrete TNF-alpha through a MAPK-dependent mechanism.</p>