Pyroptosis ; Ketoglutaric Acids ; Gasdermins ; Intracellular Signaling Peptides and Proteins/metabolism* ; Caspases/metabolism* ; Inflammasomes/metabolism*

OBJECTIVE: To investigate the role of microglial pyroptosis in hypoxic-ischemic brain damage. METHODS: An oxygen-glucose deprivation/reoxygenation (OGD/R) model of rat microglial cells were cultured in vitro. Western blot was used to measure the expression of the pyroptosis-related proteins caspase-1, interleukin-1β (IL-1β), and N-terminal gasdermin D (GSDMD-N) at 0, 1, 3, 6, 12, and 24 hours after OGD/R. After the microglial cells were transfected with lentivirus-mediated silenced gasdermin D (GSDMD), immunofluorescence assay and Western blot were used to measure the transfection rate of GSDMD. Microglial cell lines were divided into three groups: normal control, negative control, and LV-sh_GSDMD (lentivirus-mediated GSDMD silencing). CCK-8 assay and LDH kit were used to observe the effect of GSDMD silencing on the viability and toxicity of microglial cells at 24 hours after OGD/R. Western blot was used to observe the effect of GSDMD silencing on the levels of caspase-1, GSDMD-N, and IL-1β in the microglial cells at 24 hours after OGD/R. RESULTS: The expression levels of the pyroptosis-related proteins caspase-1, GSDMD-N, and IL-1β in microglial cells were upregulated since 0 hour after OGD/R and reached the peak levels at 24 hours. A microglial cell model of lentivirus-mediated GSDMD silencing was successfully constructed. At 24 hours after OGD/R, compared with the normal control group, the GSDMD silencing group had a significant increase in the cell viability and a significant reduction in the cytotoxicity (P<0.05), as well as significant reductions in the protein expression levels of caspase-1, GSDMD-N, and IL-1β in microglial cells (P<0.05). CONCLUSIONS Lentivirus silencing of the key substrate protein for pyroptosis GSDMD can alleviate hypoxic-ischemic brain damage, suggesting that microglial pyroptosis aggravates hypoxic-ischemic brain damage.
Animals ; Brain/metabolism* ; Intracellular Signaling Peptides and Proteins ; Microglia/metabolism* ; Pyroptosis ; Rats

OBJECTIVETo investigate the effect of hepatitis C virus (HCV) strain JFH1 on expression of the human gene, growth arrest and DNA damage-inducible gene 45 alpha (GADD45a), in infected hepatoma cells.

METHODSHCV JFH1 RNA-containing supernatants were used to infect the human hepatoma cell line, Huh7.5.1; infection was confirmed by Western blot detection of the HCV-encoded non-structural 5A (NS5A) protein and core protein. Infection-induced changes in GADD45a mRNA and protein expressions were measured by real time PCR using SYBR Green and Western blotting, respectively. Significance of differences between the levels detected in JFH1-infected or uninfected Huh7.5.1 cells was analyzed by single factor analysis of variance testing.

RESULTSThe HCV infection system was successfully established, as evidenced by expression of NS5A protein and core protein. The GADD45a mRNA and protein levels were significantly down-regulated in JFH1-infected Huh7.5.1 cells, by 0.57+/-0.09 and 0.28+/-0.03, respectively, as compared to levels in uninfected Huh7.5.1 cells (F values were 75.407 and 560.04, respectively; P less than 0.01).

CONCLUSIONHCV inhibits the mRNA transcription and protein expression of host GADD45a, which may contribute to the pathogenesis of hepatocellular carcinoma caused by HCV infection.

Cell Line, Tumor ; DNA Damage ; Hepacivirus ; classification ; Humans ; Intracellular Signaling Peptides and Proteins ; metabolism ; Transcription, Genetic

To explore the clinical significance of the altered expression of polycomb group (PcG)-associated protein RYBP in hepatocellular carcinoma (HCC) specimens.
 Methods: The expression levels of RYBP in tumor tissues and adjacent normal tissues in 77 HCC cases were detected by immunohistochemistry (IHC), and the relationships between RYBP expression levels and HCC clinicopathological characteristics, five-year survival rates or prognosis of HCC patients were analyzed.
 Results: RYBP expression level was significantly decreased in HCC tumor tissues than that in the adjacent normal tissues (P<0.05). The expression levels of RYBP in HCC specimens were highly correlated with HBsAg, ALT, GGT, Type III procollagen, tumor size, distant metastasis, and tumor differentiation (P<0.05). The RFS and OS for patients with RYBP-low expression were markedly lower than those with RYPB-high expression (P<0.05). Both age and RYBP expression level were protective factors for RFS, while GGT, lymph node metastasis, TNM stage, tumor differentiation and tumor size were risk factors for RFS (P<0.05). As to OS, RYBP expression level was a protective factor, while tumor number, ALT, GGT, AFP, pCEA, lymph node metastasis, TNM stage, tumor differentiation and tumor size were risk factors (P<0.05). The age, GGT, lymph node metastasis and TNM stage were independent prognostic factors for RFS (P<0.05), and both lymph node metastasis and TNM stage were independent risk factors for OS (P<0.05). Comparing to serum alpha fetoprotein (AFP) level, RYBP expression level in tumor tissues was applied to predict the prognosis of HCC patients more accurately.
 Conclusion: PcG associated protein RYBP displays a reduced expression in HCC tissues, which is related to poor prognosis of HCC patients. It might be a promising therapeutic target for HCC treatment.
Biomarkers, Tumor ; Carcinoma, Hepatocellular ; Humans ; Immunohistochemistry ; Intracellular Signaling Peptides and Proteins ; metabolism ; Liver Neoplasms ; Lymphatic Metastasis ; Prognosis

OBJECTIVETo explore the effects of TNF alpha on the expression of sterol regulatory element binding proteins cleavage activating protein (SCAP) and triglyceride contents in cells of a model of cultured steatotic hepatocytes.

METHODSA steatotic hepatocytes model was established by treating L-02 cell strain with oleic acid. The cells were treated with TNF alpha and/or TNF alpha antibody. The cells were divided into six groups: a control group (C), a model group (F), a control group with TNF alpha (C1), a control group with TNFalpha antibody (C2), a model group with TNFalpha(F1) and a model group with TNFalpha antibody (F2). The expression of SREBP-1c mRNA was measured with RT-PCR; the protein expression of SCAP was measured by Western blot; lipid droplets in the hepatocytes were observed with oil red O staining; the contents of triglyceride in hepatocytes were measured with an analytical kit.

RESULTSThe mRNA expression of SCAP in the groups treated with TNF alpha were upregulated compared with those of the control group (C1 vs C increased 67%, F1 vs F increased 55%, F = 212.98), the protein expression of SCAP in the groups treated with TNF alpha was upregulated compared with those of the control group (C1 vs C increased 45%, F1 vs F increased 95%, F = 104.3), and triglyceride contents in hepatocytes of these groups were increased compared with those of the control group [C (2.02+/-0.67) mg/10(7) cells, F(7.79+/-1.35) mg/10(7) cells, F1(13.36+/-1.99) mg/10(7) cells, F = 82.94].

CONCLUSIONTNF alpha upregulates the expression of SCAP and promotes the synthesis of triglyceride; it probably participates in the process of developing steatosis of hepatocytes.

Cell Line ; Hepatocytes ; drug effects ; metabolism ; Humans ; Intracellular Signaling Peptides and Proteins ; metabolism ; Membrane Proteins ; metabolism ; Tumor Necrosis Factor-alpha ; pharmacology

Smac is a mitochondrial protein that interacts with inhibitor of apoptosis proteins (IAPs). Upon apoptotic stimuli, the Smac is released into the cytoplasm to inhibit the capase-binding activity of IAPs. The low expression of Smac in tissues has been reported existing in various cancers. Smac plays key roles in prognosis and chemoradiotherapy resistance of malignant tumor besides neoplasm genesis and growth. Furthermore, Smac may be a molecular therapeutic target in cancer patients. Overexpression of Smac by transfecting extrinsic Smac gene or Smac mimetic into tumor cell can improve their sensitivity to radiotherapy and chemotherapy, which has great significance to the treatment of tumor. Our review will focus on the roles of Smac in structure, pro-apoptotic mechanism, tissue distribution and cancer treatment.
Humans ; Intracellular Signaling Peptides and Proteins ; chemistry ; metabolism ; physiology ; Mitochondrial Proteins ; chemistry ; metabolism ; physiology ; Neoplasms ; therapy ; Tissue Distribution

Apoptosis ; Cell Line ; Endotoxins ; adverse effects ; Hepatocytes ; cytology ; metabolism ; pathology ; Humans ; Intracellular Signaling Peptides and Proteins ; Mitochondrial Proteins

OBJECTIVE: To explore whether extracellular histones aggravate acute respiratory distress syndrome (ARDS) by inducing peripheral blood mononuclear cell (PBMC) pyroptosis. METHODS: Twenty patients with ARDS admitted to Shanghai Pulmonary Hospital, Tongji University School of Medicine from April to September in 2019 were enrolled, and 20 healthy volunteers were enrolled as controls. In vivo experiment: peripheral blood samples of patients with ARDS within 24 hours after diagnosis and healthy volunteers were collected, and the levels of plasma extracellular histone, interleukins (IL-1β and IL-18) and lactic dehydrogenase (LDH) were determined by enzyme-linked immunosorbent assay (ELISA). PBMC were harvested, the expression levels of the pyroptosis associated N terminal-gasdermin-D (GSDMD-N) protein were determined by Western Blot. In vitro experiment: PBMC isolated from healthy volunteers were divided into four groups. Blank control group without any treatment; lipopolysaccharide (LPS) group was treated with 1 mg/L LPS for 4 hours; LPS+histones group was treated with 100 mg/L exogenous histones for 24 hours after LPS treatment; LPS+histone+heparin group was treated with 200 U heparin for 24 hours after LPS and exogenous histones treatment. The GSDMD-N protein expression was determined by Western Blot, and the levels of IL-1β, IL-18 and LDH in cell supernatant were determined by ELISA. Spearman test was used to test the correlation among the parameters. RESULTS: In vivo experiment results: compared with healthy control group, the GSDMD-N protein expression in PBMC of patients with ARDS was significantly increased [GSDMD-N/GAPDH: 0.136 (0.062, 0.246) vs. 0.026 (0.018, 0.036), P < 0.01], as well as the plasma levels of IL-1β, IL-18, LDH and extracellular histones [IL-1β (ng/L): 120.0 (94.2, 213.0) vs. 88.5 (82.3, 105.3), IL-18 (ng/L): 164.5 (70.8, 236.3) vs. 60.5 (52.0, 89.0), LDH (U/L): 30.9 (24.7, 39.5) vs. 19.8 (17.2, 21.5), extracellular histones (mg/L): 73.0 (42.8, 112.9) vs. 12.2 (9.6, 16.9), all P < 0.01], indicating that the PBMC of ARDS patients had significant pyroptosis and release of a large number of inflammatory factors. The oxygenation index (PaO₂/FiO₂) of ARDS patients was 135.5 (94.5, 196.0) mmHg (1 mmHg = 0.133 kPa). Correlation analysis showed that the expression of GSDMD-N protein in patients with ARDS was negatively correlated with PaO₂/FiO₂ (r = -0.935, P < 0.01) and positively correlated with IL-1β, IL-18, LDH and extracellular histones (r value was 0.844, 0.843, 0.887, 0.899, respectively, all P < 0.01). In vitro experiment results: compared with blank control group, the expression of GSDMD-N protein in PBMC and the levels of inflammatory mediators in the supernatant of the LPS group were significantly increased [GSDMD-N/GAPDH: 0.035±0.006 vs. 0.028±0.006, IL-1β (ng/L): 39.8±5.5 vs. 22.6±4.7, IL-18 (ng/L): 31.2±4.4 vs. 20.0±2.2, LDH (U/L): 51.2±7.3 vs. 36.6±7.6, all P < 0.05], indicating that LPS stimulation could increase PBMC pyroptosis and the release of inflammatory mediators. Compared with LPS group, the expression of GSDMD-N protein and the levels of inflammatory mediators of the LPS+histones group were further increased [GSDMD-N/GAPDH: 0.114±0.009 vs. 0.035±0.006, IL-1β (ng/L): 119.0±18.7 vs. 39.8±5.5, IL-18 (ng/L): 49.2±8.5 vs. 31.2±4.4, LDH (U/L): 127.8±19.8 vs. 51.2±7.3, all P < 0.01], indicating that the stimulation of LPS on PBMC could be significantly amplified by exogenous histone treatment, GSDMD-N protein expression could be up-regulated and inflammatory factor release could be promoted to further induce PBMC pyroptosis. These adverse effects of exogenous histones on PBMC could be abrogated by heparin, the expression of GSDMD-N protein and the levels of inflammatory mediators were significantly lower than those of LPS+histones group [GSDMD-N/GAPDH: 0.063±0.004 vs. 0.114±0.009, IL-1β (ng/L): 46.8±8.6 vs. 119.0±18.7, IL-18 (ng/L): 33.0±5.1 vs. 49.2±8.5, LDH (U/L): 65.4±11.0 vs. 127.8±19.8, all P < 0.05]. CONCLUSIONS Extracellular histones in plasma may aggravate ARDS by mediating PBMC pyroptosis.
China ; Histones/metabolism* ; Humans ; Interleukin-1beta ; Intracellular Signaling Peptides and Proteins ; Leukocytes, Mononuclear ; Phosphate-Binding Proteins ; Pyroptosis ; Respiratory Distress Syndrome

Myocardial infarction afflicts close to three quarters of a million Americans annually, resulting in reduced heart function, arrhythmia, and frequently death. Cardiomyocyte death reduces the heart's pump capacity while the deposition of a non-conductive scar incurs the risk of arrhythmia. Direct cardiac reprogramming emerged as a novel technology to simultaneously reduce scar tissue and generate new cardiomyocytes to restore cardiac function. This technology converts endogenous cardiac fibroblasts directly into induced cardiomyocyte-like cells using a variety of cocktails including transcription factors, microRNAs, and small molecules. Although promising, direct cardiac reprogramming is still in its fledging phase, and numerous barriers have to be overcome prior to its clinical application. This review discusses current findings to optimize reprogramming efficiency, including reprogramming factor cocktails and stoichiometry, epigenetic barriers to cell fate reprogramming, incomplete conversion and residual fibroblast identity, requisite growth factors, and environmental cues. Finally, we address the current challenges and future directions for the field.
Animals ; Cellular Reprogramming ; Epigenesis, Genetic ; Humans ; Intercellular Signaling Peptides and Proteins ; metabolism ; Intracellular Space ; metabolism ; Myocardium ; cytology ; Signal Transduction

Idiopathic pulmonary fibrosis (IPF) is a chronic interstitial pneumonia characterized by progressive accumulation of fibroblastic foci and destruction of the alveolar structure. Due to an incomplete understanding of the mechanism of the occurrence and progression of IPF, currently no effective means have been available for its early screening or treatment. With a poor overall prognosis, the patients with IPF have a median survival of only 2-4 years. In recent years, several studies have confirmed that dozens of molecules are involved in the development of IPF and can be used as potential biomarkers. These biomarkers play important roles in early diagnosis (such as SP-D, MMP-7, and osteopontin), prognostic evaluation (such as telomerase length, KL-6, mtDNA, HSP-70, LOXL2, CXCL13, miRNA, ICAM-1, and CCL18), and guiding treatment of IPF (such as TOLLIP rs3750920 genotype, SAMS score, and SP-D), and also provide potential therapeutic targets (such as TERT, TERR, RTEC, and PARN).
Amino Acid Oxidoreductases ; metabolism ; Biomarkers ; analysis ; Disease Progression ; Humans ; Idiopathic Pulmonary Fibrosis ; diagnosis ; therapy ; Intracellular Signaling Peptides and Proteins ; metabolism ; Prognosis