Targeting the Inflammasome in Cardiovascular Disease.

The pathogenesis of cardiovascular disease (CVD) is complex and multifactorial, and inflammation plays a central role. Inflammasomes are multimeric protein complexes that are activated in a 2-step manner in response to infection or tissue damage. Upon activation the proinflammatory cytokines, interleukins-1ß and -18 are released. In the last decade, the evidence that inflammasome activation plays an important role in CVD development became stronger. We discuss the role of different inflammasomes in the pathogenesis of CVD, focusing on atherosclerosis and heart failure. This review also provides an overview of existing experimental studies and clinical trials on inflammasome inhibition as a therapeutic target in these disorders.

Compound loss of GSDMD and GSDME function is necessary to achieve maximal therapeutic effect in colitis.

Gasdermin D (GSDMD) and gasdermin E (GSDME) perpetuate inflammation by mediating the release of cytokines such as interleukin-1ß (IL-1ß) and IL-18. However, not only are the actions of GSDMD in colitis still controversial, but its interplay with GSDME in the pathogenesis of this disease has not been investigated. We sought to fill these knowledge gaps using the dextran sodium sulfate (DSS) experimental mouse colitis model. DSS ingestion by wild-type mice caused body weight loss as the result of severe gut inflammation, outcomes that were significantly attenuated in Gsdmd -/- or Gsdme -/- mice and nearly fully prevented in Gsdmd -/- ;Gsdme -/- animals. To assess the translational implications of these findings, we tested the efficacy of the active metabolite of US Food and Drug Administration (FDA)-approved disulfiram, which inhibits GSDMD and GSDME function. The severe DSS-induced gut toxicity was significantly decreased in mice treated with the inhibitor. Collectively, our findings indicate that disruption of the function of both GSDMD and GSDME is necessary to achieve maximal therapeutic effect in colitis.

A rapid increase in lysophospholipids after geranylgeranoic acid treatment in human hepatoma-derived HuH-7 cells revealed by metabolomics analysis.

Geranylgeranoic acid (GGA) was developed as a preventative agent against second primary hepatoma, and was reported to induce cell death in human hepatoma cells via Toll-like receptor 4 (TLR4)-mediated pyroptosis. We recently reported that GGA is enzymatically biosynthesized from mevalonic acid in human hepatoma-derived HuH-7 cells and that endogenous GGA is found in most rat organs including the liver. An unbiased metabolomics analysis of ice-cold 50% acetonitrile extracts from control and GGA-treated cells was performed in this study to characterize the intracellular metabolic changes in GGA-induced pyroptosis and to analyze their relationship with the mechanism of GGA-induced cell death. The total positive ion chromatograms of the cellular extracts in ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry were apparently unchanged after GGA treatment, but an orthogonal partial least squares-discriminant analysis score plot clearly discriminated the intracellular metabolite profiles of GGA-treated cells from that of control cells. S-plot analysis revealed 15 potential biomarkers up-regulated by 24-h GGA treatment according to their variable importance in the projection value of more than 1, and the subsequent metabolomics analysis identified nine of these metabolites as a group of lysophospholipids containing lysophosphatidylcholine with C16:0, C20:4, or C20:3 fatty acids. The possible roles of these lysophospholipids in GGA-induced pyroptosis are discussed.

Role of pyroptosis in spinal cord injury and its therapeutic implications.

BACKGROUND: Currently, spinal cord injury (SCI) is a pathological incident that triggers several neuropathological conditions, leading to the initiation of neuronal damage with several pro-inflammatory mediators' release. However, pyroptosis is recognized as a new programmed cell death mechanism regulated by the stimulation of caspase-1 and/or caspase-11/-4/-5 signaling pathways with a series of inflammatory responses. AIM: Our current review concisely summarizes the potential role of pyroptosis-regulated programmed cell death in SCI, according to several molecular and pathophysiological mechanisms. This review also highlights the targeting of pyroptosis signaling pathways and inflammasome components and its therapeutic implications for the treatment of SCI. KEY SCIENTIFIC CONCEPTS: Multiple pieces of evidence have illustrated that pyroptosis plays significant roles in cell swelling, plasma membrane lysis, chromatin fragmentation and intracellular pro-inflammatory factors including IL-18 and IL-1ß release. In addition, pyroptosis is directly mediated by the recently discovered family of pore-forming protein known as GSDMD. Current investigations have documented that pyroptosis-regulated cell death plays a critical role in the pathogenesis of multiple neurological disorders as well as SCI. Our narrative article suggests that inhibiting the pyroptosis-regulated cell death and inflammasome components could be a promising therapeutic approach for the treatment of SCI in the near future.

Regulatory roles of ginseng on inflammatory caspases, executioners of inflammasome activation.

Inflammation is an immune response that protects against pathogens and cellular stress. The hallmark of inflammatory responses is inflammasome activation in response to various stimuli. This subsequently activates downstream effectors, that is, inflammatory caspases such as caspase-1, 4, 5, 11, and 12. Extensive efforts have been made on developing effective and safe anti-inflammatory therapeutics, and ginseng has long been traditionally used as efficacious and safe herbal medicine in treating various inflammatory and inflammation-mediated diseases. Many studies have successfully shown that ginseng plays an anti-inflammatory role by inhibiting inflammasomes and inflammasome-activated inflammatory caspases. This review discusses the regulatory roles of ginseng on inflammatory caspases in inflammatory responses and also suggests new research areas on the anti-inflammatory function of ginseng, which provides a novel insight into the development of ginseng as an effective and safe anti-inflammatory herbal medicine.

Miltirone induces cell death in hepatocellular carcinoma cell through GSDME-dependent pyroptosis.

Pyroptosis is a form of programmed cell death, and recently described as a new molecular mechanism of chemotherapy drugs in the treatment of tumors. Miltirone, a derivative of phenanthrene-quinone isolated from the root of Salvia miltiorrhiza Bunge, has been shown to possess anti-cancer activities. Here, we found that miltirone inhibited the cell viability of either HepG2 or Hepa1-6 cells, and induced the proteolytic cleavage of gasdermin E (GSDME) in each hepatocellular carcinoma (HCC) cell line, with concomitant cleavage of caspase 3. Knocking out GSDME switched miltirone-induced cell death from pyroptosis to apoptosis. Additionally, the induction effects of miltirone on GSDME-dependent pyroptosis were attenuated by siRNA-mediated caspase three silencing and the specific caspase three inhibitor Z-DEVD-FMK, respectively. Miltirone effectively elicited intracellular accumulation of reactive oxygen species (ROS), and suppressed phosphorylation of mitogen-activated and extracellular signal-regulated kinase (MEK) and extracellular regulated protein kinases 1/2 (ERK1/2) for pyroptosis induction. Moreover, miltirone significantly inhibited tumor growth and induced pyroptosis in the Hepa1-6 mouse HCC syngeneic model. These results provide a new insight that miltirone is a potential therapeutic agent for the treatment of HCC via GSDME-dependent pyroptosis.

Establishment and significance of pyrolysis model of human trophoblast HTR-8/SVneo induced by hydrogen peroxide / 医学研究生学报

ObjectiveA good invasion ability of extravilloustrophoblas (EVTs) is the prerequisite for successful placental colonization and effective remodeling of the uterine spiral artery. This article aims to simulate the pathophysiological process of oxidative stress inducing trophoblasts to pyroptosis in vitro, exploring the correlation between trophoblasts pyroptosis and the pathogenesis of preeclampsia.MethodsTwenty-five patients with preeclampsia were selected from the Department of Obstetrics and Gynecology, Zhongda Hospital affiliated to Southeast University from September 2017 to January 2019. Among them, early-onset preeclampsia (gestational weeks<34) was early-onset group (n=17), late-onset preeclampsia (gestational weeks≥34) was late-onset group (n=8), and full-term pregnant women with normal blood pressure (39＜gestational weeks＞42) were selected as normal group (n=10). Human trophoblasts were cultured with HTR-8/SVneo for 12 hours, and then treated with H2O2 (100, 150, 200, 250μmol/L) (2, 4, 6, 12 h), to induce human trophoblast HTR-8/SVneo pyrolysis model; the control group was normal cultured cells of 1640+10% fetal bovine serum + 1% antibiotics. Placental specimens from 7 patients with preeclampsia were randomly selected, including 3 cases in early onset group, 4 cases in late onset group and 1 case in normal group. The total proteins of cells and placenta were extracted respectively, and the expression of scorch death-related molecular proteins was detected. The mRNA levels of pyroptosis related molecules in cells was detected by RT-qPCR, and the morphological changes of cells were observed by inverted phase contrast microscope.ResultsThe Western blot results showed that the activation of the key molecular activation form of the cell pyrogenesis pathway, Cleaved caspase1, could be detected in the placenta. When H2O2 was 150 mol/L for 2h, the mRNA levels of NLRP3 and IL-1, the key molecules of the upstream activation signal, were significantly up-regulated (8.680±0.481, 14.136±0.244) compared with the control group (1.00±0.00) (P<0.000). At 4h, mRNA levels of key molecule GSDMD and downstream inflammatory factor IL-18 (1.639±0.354 and 1.794±0.043) in the pyrogenesis pathway were significantly higher than those in the control group (1.00±0.00), with statistically significant differences (P<0.05). By reverse validation of the mRNA levels of the molecules associated with pyroptosis, the optimal conditions of the model induced by H2O2 were 150 mol/L and 4h, and the typical changes, such as cell swelling, fragmentation and plasma membrane bubble formation, could be seen under the light microscope.ConclusionThe pyroptosis model of trophoblast cells was successfully established, and the physiological process of oxidative stress inducing trophoblasts to pyroptosis in vitro was successfully simulated, providing new ideas and directions for the diagnosis and treatment of preeclampsia and the development of new drugs.