Role of NOD-like receptor protein 3 inflammasome in the development and progression of hepatocellular carcinoma / 临床肝胆病杂志

In recent years， NOD-like receptor protein 3 （NLRP3） inflammasome in tumors has become a research hotspot， especially in melanoma， colorectal cancer， lung cancer， and breast cancer， and more and more evidence has shown that inflammation plays a role in the development， progression， angiogenesis， and invasion of cancer. Hepatocellular carcinoma （HCC） is the most common type of primary liver cancer， and there are still controversies over the role of NLRP3 inflammasome in the development and progression of HCC. Therefore， this article reviews the potential impact of NLRP3 inflammasome in the progression of HCC and its mechanism of action in anticancer therapy， and it is believed that NLRP3 inflammasome can be used as an effective therapeutic target for HCC patients.

Effect of Dendrobium officinale leaf fermentation fluid on a mouse model of alcoholic hepatitis and its mechanism of action / 临床肝胆病杂志

ObjectiveTo investigate the intervention mechanism of Dendrobium officinale leaf fermentation fluid in mice with alcoholic hepatitis. MethodsA total of 70 healthy male C57BL/6J mice， aged 6-8 weeks， were randomly divided into normal group， model group， liquid feed control group， silybin group， and low-， middle-， and high-dose Dendrobium officinale leaf fermentation fluid groups， with 10 mice in each group. The mice in the normal group were given normal diet， and those in the other groups were given Lieber-DeCarli classic liquid diet for 8 weeks to induce alcoholic hepatitis. During modeling， the mice in the low-， middle-， and high-dose Dendrobium officinale leaf fermentation fluid groups were given Dendrobium liquid manufactured by Warmen Pharmaceutical， and the mice in all the other groups were given pure water； the mice in the normal group， the model group， and the liquid feed control group were given normal saline by gavage， those in the silybin group were given silybin 0.25 mL/10 g by gavage， and those in the low-， middle-， and high-dose Dendrobium officinale leaf fermentation fluid groups were given Dendrobium officinale leaf fermentation fluid at a dose of 0.125 mL/10 g， 0.250 mL/10 g， and 0.375 mL/10 g， respectively， by gavage， once a day. At week 8， chloral hydrate was injected intraperitoneally for anesthesia， and blood samples were collected from the eyeball. After serum was separated， the biochemical method was used to measure the levels of aspartate aminotransferase （AST） and alanine aminotransferase （ALT）； HE staining and oil red staining were used to observe liver histopathology and lipid accumulation in mice； multiplex Luminex assay was used to measure the serum levels of interleukin-6 （IL-6）， interleukin-1β （IL-1β）， tumor necrosis factor-α （TNF-α）， and CCL2； quantitative real-time PCR， Western blot， and immunofluorescence assay were used to measure the protein expression levels of NLRP3， caspase-1， caspase-11， gasdermin D （GSDMD）， N-terminal gasdermin D （GSDMD-N） in liver tissue. A one-way analysis of variance was used for comparison of continuous data between multiple groups， and the least significant difference t-test was used for further comparison between two groups. ResultsCompared with the normal group， the model group had significant increases in the serum levels of AST， ALT， IL-6， IL-1β， TNF-α， and CCL2 （all P<0.05）， and compared with the model group， the high-dose Dendrobium officinale leaf fermentation fluid group had significant reductions in the serum levels of AST， ALT， IL-6， IL-1β， TNF-α， and CCL2 （all P<0.05）. HE staining showed that the model group had disordered structure of hepatic lobules， with a large number of steatosis vacuoles and massive cell necrosis， and compared with the model group， the high-dose Dendrobium officinale leaf fermentation fluid group had alleviation of liver histopathological injury， intact structure of most hepatic lobules， and a small amount of inflammatory cell infiltration. Oil red staining showed that the model group had accumulation of large and small lipid droplets in the liver and a significant increase in liver fat content， and compared with the model group， the high-dose Dendrobium officinale leaf fermentation fluid group had significant alleviation of hepatic steatosis， with the presence of sporadic small lipid droplets. Immunofluorescence assay of liver tissue showed that compared with the normal group， the model group had a significant increase in the ratio of GSDMD-positive staining area in hepatocyte cytoplasm （P<0.001）， and compared with the model group， the high-dose Dendrobium officinale leaf fermentation fluid group had a significant reduction in such ratio in hepatocyte cytoplasm （P<0.001）. Quantitative real-time PCR showed that compared with the normal group， the model group had significant increases in the protein expression levels of NLRP3， caspase-1， caspase-11， GSDMD， GSDMD-N， interleukin-18 （IL-18）， and IL-1β in liver tissue （all P<0.05）， and compared with the model group， the high-dose Dendrobium officinale leaf fermentation fluid group had significant reductions in the protein expression levels of NLRP3， caspase-1， caspase-11， GSDMD， GSDMD-N， IL-18， and IL-1 （all P<0.05）. Compared with the model group， the high-dose Dendrobium officinale leaf fermentation fluid group had significant reductions in the protein expression levels of caspase-1 and caspase-11 （both P<0.05）， with a relative expression level of caspase-1 of 1.757 （reduced by 26.6% compared with the model group） and a relative expression level of caspase-11 of 0.455 （reduced by 70.3% compared with the model group）， suggesting that caspase-11 showed a greater reduction than caspase-1. ConclusionDendrobium officinale leaf fermentation fluid can alleviate alcoholic hepatitis in mice， possibly by inhibiting the non-classical cell pyroptosis pathway mediated by caspase-11.

Mechanism of Traditional Chinese Medicine Intervening in Pyroptosis to Prevent and Treat Bone and Joint Related Diseases： A Review / 中国实验方剂学杂志

Osteoarthritis （OA）， rheumatoid arthritis （RA）， gouty arthritis （GA）， and intervertebral disc degeneration （IVDD） are the most common bone and joint-related diseases in clinical practice. They can all affect related joints， leading to joint pain， swelling， dysfunction， and other symptoms. The difference is that OA is mainly caused by joint wear and age-related degradation and is manifested as joint pain， stiffness， and limited movement. RA is an autoimmune disease， manifested as joint pain， swelling， morning stiffness， and systemic symptoms. GA is caused by abnormal uric acid metabolism， manifested as acute arthritis， and IVDD is caused by intervertebral disc degeneration. Studies have shown that the mechanism of the occurrence and development of these bone and joint diseases is extremely complex. Pyroptosis is closely related to these bone and joint-related diseases by participating in bone and joint inflammation， cartilage metabolism imbalance， extracellular matrix degradation， and pathological damage of bone and joint. Inhibition of bone and joint-related pyroptosis will effectively prevent and treat bone and joint-related diseases. At the same time， many studies have confirmed that traditional Chinese medicine （TCM） has a prominent curative effect and obvious advantages in the prevention and treatment of bone and joint-related diseases. TCM can reduce the inflammatory reaction of bone and joints， improve the pathological damage of bone and joint diseases， and relieve bone and joint pain by inhibiting pyroptosis. Therefore， this article aims to briefly explain the relationship between pyroptosis and the occurrence and development of bone and joint-related diseases and summarize the latest research reports on the intervention of pyroptosis in the treatment of bone and joint-related diseases by TCM monomers， TCM extracts， and TCM compounds. It offers new ideas for the in-depth study of the pathogenesis and drug treatment of bone and joint diseases and provides a basis for the clinical use of TCM to prevent and treat bone and joint diseases.

The Effect of Shenqi Jianxin Formula （参芪健心方） on Cardiomyocyte Pyroptosis in Chronic Heart Failure Model Rats Based on the NLRP3/Caspase-1 Signaling Pathway / 中医杂志

ObjectiveTo investigate the possible mechanism of Shenqi Jianxin Formula （参芪健心方） in the treatment of chronic heart failure （CHF） from the perspective of pyroptosis. MethodsFifty-two rats were randomly divided into sham operation group （n=8） and modeling group （n=44）. In the modeling group， the anterior descending branch of the left coronary artery was ligated to construct CHF rat model. Forty successfully-modelled rats were randomly divided into model group， Entresto group， Shenqi Jianxin Formula group， MCC950 group and the combination group （Shenqi Jianxin Formula plus MCC950）， with 8 rats in each group. In Shenqi Jianxin Formula group， 7.4 g/（kg·d） of Shenqi Jianxin Formula was given by gavage， while in Entresto group， 68 mg/（kg·d） of Entresto suspension was given by gavage； in MCC950 group， MCC950 was injected intraperitoneally with 10 mg/kg once every other day， and in the combination group， 7.4 g/（kg·d） of Shenqi Jianxin Formula was given by gavage， and MCC950 was injected intraperitoneally with 10 mg/kg once every other day； 10 ml/（kg·d） of saline was given by gavage in the sham operation group and the model group. After 3 weeks of continuous intervention， serum brain B-type natriuretic peptide （BNP）， creatine kinase isoenzyme MB （CK-MB）， interleukin 1β （IL-1β）， and interleukin 18 （IL-18） levels were detected by ELISA； HE staining and MASSON staining were used to observe pathological changes in rat myocardium. Except for the Entresto group， western blot technique was used to detect the expression of NOD-like receptor protein 3 （NLRP3）， caspase-1， and apoptosis-associated speck-like protein possessing a caspase-recruiting domain （ASC）； RT-PCR was used to detect the expression of NLRP3 and caspase-1 mRNA. ResultsCompared with the sham operation group， HE staining of rats in the model group showed obvious myocardial injury， while MASSON staining showed increased area of collagen fibrosis， and serum BNP， CK-MB， IL-1β， IL-18， myocardial tissue NLRP3， caspase-1， ASC protein expression and NLRP3， caspase-1 mRNA expression were all elevated （P＜0.05）. Compared with those in the model group， cardiomyocyte injury of rats and collagen fibrosis area were reduced， and serum BNP， CK-MB， IL-1β， and IL-18 contents were all reduced in Shenqi Jianxin Formula group， Entresto group， MCC950 group， and the combination group； except for Entresto group， myocardial tissue NLRP3， caspase-1， ASC protein expression and NLRP3， caspase-1 mRNA expression were reduced in the remaining three medication group （P＜0.05）. Compared with Shenqi Jianxin Formula group， the MCC950 group and the combination group showed decreased serum IL-1β and IL-18 content， collagen fibrosis area， myocardial tissue NLPR3， caspase-1 protein expression， and caspase-1 mRNA expression， and decreased ASC and NLRP3 mRNA expression was shown in the combination group （P＜0.05）. Compared with MCC950 group， collagen fibrosis area was reduced， and serum IL-18 content， NLRP3， caspase-1 mRNA expression were reduced in the combination group （P＜0.05）. ConclusionShenqi Jianxin Formula can effectively improve the myocardial injury and heart failure in rats with CHF， and its mechanism may be related to the inhibition of cardiomyocyte pyroptosis through NLPR3/Caspase-1 pathway to reduce the level of intramyocardial inflammation. The combined use of MCC950 with Shenqi Jianxin Formula could more effectively inhibite myocardial pyroptosis， with better therapeutic result than single use of each part.

Effect of Salvianolic Acid B Combined with Puerarin on Pyroptosis of SH-SY5Y Cells Injured by Oxygen-glucose Deprivation/Reoxygenation / 中国实验方剂学杂志

ObjectiveTo investigate the effect and mechanism of salvianolic acid B combined with puerarin in protecting the SH-SY5Y cells from the damage by oxygen-glucose deprivation/reoxygenation （OGD/R） based on pyroptosis. MethodSH-SY5Y cells were used to establish the model of OGD/R， and cells were classified into the control， OGD/R， 10 μmol·L-1 salvianolic acid B， 100 μmol·L-1 puerarin， 10 μmol·L-1 salvianolic acid B + 100 μmol·L-1 puerarin， and 10 μmol·L-1 NOD-like receptor protein 3 （NLRP3） inhibitor MCC950 groups. Except the control group， other groups were rapidly reoxygenated for 12 h after 6 h OGD for modeling. The cell survival rate was determined by the methyl thiazolyl tetrazolium （MTT） assay. An optical microscope was used to observe the cell morphology. A spectrophotometer was used to determine the content of lactic dehydrogenase （LDH） in culture supernatant. Cell damage was measured by Hoechst/PI staining. The mRNA levels of NLRP3， cysteinyl aspartate specific proteinase-1 （Caspase-1）， gasdermin D （GSDMD）， apoptosis-associated speck-like protein （ASC）， and interleukin-1β （IL-1β） were determined by real-time fluorescence quantitative polymerase chain reaction （Real-time PCR）. The protein activation of Caspase-1 and NLRP3 was detected by immunofluorescence. Western blot was employed to determine the protein levels of IL-1β， ASC， NLRP3， Caspase-1， and cleaved Caspase-1. ResultCompared with the control group， the OGD/R group showed decreased cell survival rate （P<0.01）， damaged cell morphology， increased leakage rate of LDH （P<0.01）， up-regulated mRNA levels of NLRP3， Caspase-1， GSDMD， ASC， and IL-1β （P<0.01）， and up-regulated protein levels of IL-1β， ASC， NLRP3， Caspase-1， and cleaved Caspase-1 （P<0.01）. Compared with the OGD/R group， salvianolic acid B， puerarin， and salvianolic acid B combined with puerarin improved cell survival rate （P<0.01）， and the combined treatment group outperformed salvianolic acid B and puerarin used alone （P<0.01）. Salvianolic acid B combined with puerarin and MCC950 both improved cell morphology， reduced the leakage of LDH （P<0.01）， alleviated cell damage， and down-regulated the mRNA levels of NLRP3， Caspase-1， GSDMD， ASC， and IL-1β （P<0.05， P<0.01） and also the protein levels of IL-1β， ASC， NLRP3， Caspase-1， and cleaved Caspase-1 （P<0.05， P<0.01）. ConclusionThe results indicated that salvianolic acid B combined with puerarin can alleviate the OGD/R-induced damage of SH-SY5Y cells by inhibiting pyroptosis.

Research progress in RIPK3 and its inhibitors / 中国药理学通报

Receptor-interacting serine/threonine-protein kinase 3(RIPK3),a member of the RIP kinase family,plays an important role in cell death,especially in necroptosis. In addition,RIPK3 is also involved in apoptosis and pyroptosis,suggesting that RIPK3 may be the intersection of multiple cell death and it possesses the potential to be a target for precise regulation of cell death. According to the kinase binding mode,current RIPK3 inhibitors can be classified into type ,type Ⅱ and other types. This review summarizes the research progress in the role of RIPK3 in cell death and its inhibitors,which is of great significance in seeking drugs for the treatment of injury-related diseases.

Advances in relationship between pyroptosis and pulmonary arterial hypertension and therapeutic drugs / 中国药理学通报

Pyroptosis is the programmed death of cells accompanied by an inflammatory response and is widely involved in the development of a variety of diseases, such as infectious diseases, cardiovascular diseases, and neurodegeneration. It has been shown that cellular scorching is involved in the pathogenesis of pulmonary arterial hypertension ( PAH) in cardiovascular diseases. Patients with PAH have perivascular inflammatory infiltrates in lungs, pulmonary vasculopathy exists in an extremely inflam-matory microenvironment, and pro-inflammatory factors in cellular scorching drive pulmonary vascular remodelling in PAH patients. This article reviews the role of cellular scorch in the pathogenesis of PAH and the related research on drugs for the treatment of PAH, with the aim of providing new ideas for clinical treatment of PAH.

Tripterine promotes pyroptosis of liver cancer cells by regulating ATF4/caspase-3/GSDME signaling pathway / 中国药理学通报

Aim To explore the new mechanism of triptolide (TRI) inhibiting the progression of hepatocellular carcinoma (HCC) . Methods Different concentrations (0, 0 . 5, 2, and 8 jjunol • L~) of TRI were administered to act on liver cancer cells, and then the cell phenotypes and possible mechanisms were explored using experimental methods such as CCK-8, cell cloning, Transwell, and protein immunoblotting; siRNA was used to interfere with the target gene GSDME and its role was determined. Finally, the mechanism of TRI inhibiting the growth of HCC cells in vivo was validated using a transplanted tumor model. Results TRI could inhibit the proliferation, cloning, and invasion of HCC cells, and promote cell apoptosis. Immunoblotting results showed that the expression of GSDME was significantly upregulated in HepG2 or He-pal-6 hepatocellular carcinoma after TRI treatment, while the expression of cleaved caspase-3 and PARP also significantly increased. Knocking out GSDME could partially reverse TRI-induced cell apoptosis. At the same time, cells knocked down by GSDME had stronger cloning and migration abilities, and the apoptosis rate was reduced compared to the TRI treatment group alone. In vivo experiments showed that TRI inhibited HCC tumor growth, and the TRI + siGSDME group had a faster tumor growth rate than the TRI treatment group alone did. In addition, after TRI stimulation, p-eIF2a and ATF4 in HepG2 and Hepal-6 cells significantly increased. The immunofluorescence results showed a dose-dependent increase in the number of ATF4 positive cells in HepG2 and Hepal-6 cells after TRI stimulation. Conclusion The inhibitory effect of TRI on the growth and invasion of liver cancer cells may be related to its regulation of the ATF4/caspase-3/GSDME signaling pathway and promotion of liver cancer cell apoptosis.

Salvianolic Acid F Regulates Bax/Caspase-3/GSDME Signaling Pathway to Inhibit Pyroptosis of HK-2 Cells / 中国实验方剂学杂志

ObjectiveTo investigate the mechanism of salvianolic acid F （Sal F） in repairing the high glucose-induced injury in human kidney-2 （HK-2） cells via the B-cell lymphoma-2 （Bcl-2）-associated X protein （Bax）/cysteinyl aspartate-specific proteinase 3 （Caspase-3）/gasdermin-E （GSDME） pathway. MethodThe cell counting kit-8 （CCK-8） was used to measure the relative viability of HK-2 cells exposed to high glucose and different concentrations （2.5， 5， 10， 20 μmol·L-1） of Sal F and the relative viability of HK-2 cells treated with Sal F for different time periods. The levels of lactate dehydrogenase （LDH） and interleukin-1β （IL-1β） in the supernatant of the cell culture were measured by the LDH assay kit and enzyme-linked immunosorbent assay （ELISA） kit， respectively. Flow cytometry combined with Annexin V-FITC/propidium iodide （PI） and Hoechst 33342/PI staining was employed to reveal the proportion of PI-positive HK-2 cells exposed to high glucose. Western blotting was employed to determine the protein levels of Bax， Bcl-2， cytochrome C， cysteinyl aspartate-specific proteinase （Caspase）-9， Caspase-3， and GSDME in the HK-2 cells exposed to high glucose and treated with Sal F. The 2，7-dichlorodihydrofluorescein diacetate fluorescence probe （DCFH-DA） and mitochondrial membrane potential assay kit （JC-1） were used to determine the production of reactive oxygen species （ROS） and the mitochondrial membrane potential in the HK-2 cells exposed to high glucose and treated with Sal F. ResultCompared with the blank group， the model group showed decreased cell viability （P<0.01）， elevated levels LDH and IL-1β， increased proportion of PI-positive cells （P<0.01）， up-regulated protein levels of Bax， cytochrome C， Caspase-9， Caspase-3， and GSDME （P<0.01）， down-regulated protein level of Bcl-2 （P<0.01）， decreased mitochondrial membrane potential， and excessive ROS accumulation. Compared with the model group， Sal F repaired the high glucose-induced injury in HK-2 cells （P<0.05）， lowered the levels of LDH and IL-1β （P<0.05， P<0.01）， and decreased the proportion of PI-positive cells （P<0.01）. In addition， Sal F down-regulated the protein levels of Bax， cytochrome C， Caspase-9， Caspase-3， and GSDME and up-regulated the protein level of Bcl-2 （P<0.05， P<0.01）， increased the mitochondrial membrane potential， and decreased the accumulation of ROS in HK-2 cells. ConclusionSal F can reduce the production of ROS， restore the balance of mitochondrial membrane potential， and inhibit pyroptosis via the Bax/Caspase-3/GSDME signaling pathway to repair the high glucose-induced injury in HK-2 cells.

Scutellariae Radix-Coptidis Rhizoma Treats Atherosclerosis via NLRP3 Inflammasome-mediated Pyroptosis of Macrophages / 中国实验方剂学杂志

ObjectiveTo investigate the therapeutic effect of Scutellariae Radix-Coptidis Rhizoma （SRCR） on atherosclerosis （AS） in mice and the effect of SRCR on macrophage pyroptosis in plaques via NOD-like receptor thermal protein domain-associated protein 3 （NLRP3） inflammasomes. MethodApoE-/- mice were fed with a high-fat diet for the modeling of AS and randomized into model， atorvastatin （5 mg·kg-1）， and low-， medium-， and high-dose （1.95， 3.9， 7.8 g·kg-1， respectively） SRCR groups. Normal C57BL/6J mice were selected as the control group. After 8 weeks of administration， hematoxylin-eosin staining was used to observe the pathological status of the aortic plaque. The lipid accumulation in aortic plaque was observed by oil red O staining. The serum levels of total cholesterol （TC）， triglyceride （TG）， high-density lipoprotein cholesterol （HDL-C）， and low-density lipoprotein cholesterol （LDL-C） in mice were measured. Immunofluorescence double staining was employed to detect the co-localized expression of EGF-like module-containing mucin-like hormone receptor-like 1 （EMR1）/NLRP3 and EMR1/gasdermin D （GSDMD）. The serum levels of interleukin-1β （IL-1β） and interleukin-18 （IL-18） were determined by enzyme-linked immunosorbent assay （ELISA）. The protein levels of NLRP3， apoptosis-associated speck-like protein （ASC）， Caspase-1， cleaved Caspase-1， GSDMD， N-terminus of GSDMD （GSDMD-NT）， pro-IL-1β， IL-1β， and IL-18 were determined by Western blot， and the mRNA levels of NLRP3， ASC， Caspase-1， GSDMD， IL-1β， and IL-18 were determined by Real-time fluorescence quantitative polymerase chain reaction （Real-time PCR）. ResultCompared with the control group， the model group showed obvious plaques， elevated serum levels of TG， TC， LDL-C， IL-1β， and IL-18 （P<0.01）， lowered serum level of HDL-C （P<0.01）， and up-regulated expression of NLRP3 inflammasomes and molecules related to pyroptosis in the aortic plaques （P<0.01）. Compared with the model group， SRCR， especially at the medium and high doses， alleviated the plaque pathology， reduced the lipid content in plaques （P<0.05， P<0.01）， recovered the serum lipid levels （P<0.05）， reduced the macrophage recruitment （P<0.01）， activation of NLRP3 inflammasomes， and pyroptosis in aortic root plaques （P<0.05）， lowered the serum IL-1β and IL-18 levels （P<0.01）， and down-regulated the protein levels of NLRP3， ASC， Caspase-1， cleaved Caspase-1， GSDMD， GSDMD-NT， pro-IL-1β， IL-1β， and IL-18 （P<0.05） and the mRNA levels of NLRP3， ASC， Caspase-1， GSDMD， IL-1β， and IL-18 in the aortic tissue （P<0.05）. ConclusionSRCR exerts a therapeutic effect on high-fat diet-induced AS in mice by inhibiting the activation NLRP3 inflammasomes and reducing the pyroptosis of macrophages in plaques.

Acidic Environment Induces Pyroptosis of NLRP3 Inflammatory Vesicle-Mediated Nucleus Pulposus Cells Through Up-Regulation of POSTN Expression

SUMMARY: Intervertebral disc degeneration (IVDD) is induced by nucleus pulposus (NP) dysfunction as a result of massive loss of NP cells. It has been reported that the acidic microenvironment of the intervertebral disc (IVD) can induce NP cell pyroptosis, and that up-regulation of periostin (POSTN) expression has a negative effect on NP cell survival. However, the relationship between the acidic environment, POSTN expression level and NP cell pyroptosis is unclear. Therefore, the aim of this study was to explore the relationship between acidic environment and POSTN expression level in NP cells, as well as the effect of POSTN in acidic environment on NP cell pyroptosis. NP cells were obtained from the lumbar vertebrae of Sprague Dawley (SD) male rats. These cells were divided into normal and acidic groups according to whether they were exposed to 6 mM lactic acid solution. And NP cells in the acidic group were additionally divided into three groups: (1) Blank group: no transfection; (2) NC group: cells transfected with empty vector plasmid; (3) sh-POSTN group: cells transfected with sh-POSTN plasmid to knock down the expression level of POSTN. Quantitative real-time PCR (qRT-PCR) and western blot was performed to assess the expression of POSTN at the mRNAand protein levels. CCK8 was used to evaluate cell survival. Western blot, in addition, was performed to examine acid-sensing ion channels (ASIC)-related proteins. And pyroptosis was detected by ELISA and western blot. The expression level of POSTN was significantly increased in NP cells in acidic environment. Knockdown of POSTN expression promoted the survival of NP cells in acidic environment and reduced the protein levels of ASIC3 and ASIC1a in NP cells. Moreover, knockdown of POSTN expression decreased the pyroptosis proportion of NP cells and the levels of pro-inflammatory cytokines interleukin (IL)-1β and IL-18. The levels of pyroptosis-related proteins NLRP3, ASC, cleaved-Caspase-1, and cleaved-GSDMD were also affected by the decreased POSTN expression. The extracellular acidic environment created by lactic acid solution activated NLRP3 inflammatory vesicle-induced caspase-1 to get involved in NP cell pyroptosis by up-regulating POSTN expression.

La degeneración del disco intervertebral (DDIV) es inducida por una disfunción del núcleo pulposo (NP) como resultado de una pérdida masiva de células NP. Se ha informado que el microambiente ácido del disco intervertebral (DIV) puede inducir la piroptosis de las células NP y que la regulación positiva de la expresión de periostina (POSTN) tiene un efecto negativo en la supervivencia de las células NP. Sin embargo, la relación entre el ambiente ácido, el nivel de expresión de POSTN y la piroptosis de las células NP es poco clara. Por lo tanto, el objetivo de este estudio fue explorar la relación entre el ambiente ácido y el nivel de expresión de POSTN en células NP, así como el efecto de POSTN en ambiente ácido sobre la piroptosis de las células NP. Las células NP se obtuvieron de las vertebras lumbares de ratas macho Sprague Dawley (SD). Estas células se dividieron en grupos normales y ácidos según se expusieron a una solución de ácido láctico 6 mM. Las células NP en el grupo ácido se dividieron adicionalmente en tres grupos: (1) Grupo en blanco: sin transfección; (2) grupo NC: células transfectadas con plásmido vector vacío; (3) grupo sh-POSTN: células transfectadas con plásmido sh-POSTN para reducir el nivel de expresión de POSTN. Se realizó una PCR cuantitativa en tiempo real (qRT-PCR) y una transferencia Western para evaluar la expresión de POSTN en los niveles de ARNm y proteína. Se utilizó CCK8 para evaluar la supervivencia celular. Además, se realizó una transferencia Western para examinar las proteínas relacionadas con los canales iónicos sensibles al ácido (ASIC). La piroptosis se detectó mediante ELISA y Western blot. El nivel de expresión de POSTN aumentó significativamente en células NP en ambiente ácido. La eliminación de la expresión de POSTN promovió la supervivencia de las células NP en un ambiente ácido y redujo los niveles de proteína de ASIC3 y ASIC1a en las células NP. Además, la eliminación de la expresión de POSTN disminuyó la proporción de piroptosis de las células NP y los niveles de citocinas proinflamatorias interleucina (IL) - 1β e IL-18. Los niveles de proteínas relacionadas con la piroptosis NLRP3, ASC, Caspasa-1 escindida y GSDMD escindida también se vieron afectados por la disminución de la expresión de POSTN. El ambiente ácido extracelular creado por la solución de ácido láctico activó la caspasa-1 inducida por vesículas inflamatorias NLRP3 para involucrarse en la piroptosis de las células NP mediante la regulación positiva de la expresión de POSTN.

Mechanism underlying Müller cell pyroptosis and its role in the development of proliferative vitreoretinopathy

Abstract Objectives To explore the mechanism underlying Müller Cell Pyroptosis (MCP) and its role in the development of Proliferative Vitreoretinopathy (PVR). Method The expression of pyroptosis-related factors, namely, cysteinyl aspartate-specific proteinase (caspase-1), interleukin (IL)-1β, IL-18, and Gasdermin D (GSDMD), was detected by quantitative Reverse Transcription Polymerase Chain Reaction (qRT-PCR) and western blotting at the mRNA and protein levels, respectively, in retinal tissues. Müller and spontaneously Arising Retinal Pigment Epithelia (ARPE)-19 primary cells with GSDMD overexpression or knockdown were cultivated. Western blotting was used to detect the levels of the following pyroptosis-related factors in retinal tissues: caspase-1, IL-1β, IL-18, and GSDMD. Through Cell Adhesion (CA) experiments, the changes in ARPE-19 CA in each group were observed. The migration and invasion of ARPE-19 cells were measured using the Transwell assay. The proliferation of ARPE-19 cells was measured with a Cell Counting Kit 8 (CCK-8) assay. Finally, the expression of the cytokines IL-1β and IL-18 in the ARPE-19 cell culture medium was detected using the Enzyme-Linked Immunosorbent Assay (ELISA). Results Compared with the surrounding normal tissues, the expression of caspase-1, IL-1β, IL-18, and GSDMD at the protein and mRNA levels in the retinal proliferative membrane samples of the patients decreased significantly (p < 0.05). MCP significantly enhanced ARPE-19 CA, migration and invasion, proliferation, and cytokine expression (p < 0.05). Conclusions MCP can promote the development of PVR lesions.

Alpha-kinase1 promotes tubular injury and interstitial inflammation in diabetic nephropathy by canonical pyroptosis pathway

BACKGROUND: Alpha-kinase 1 (ALPK1) is a master regulator in inflammation and has been proved to promote renal fibrosis by promoting the production of IL-1ß in diabetic nephropathy (DN) mice. Pyroptosis is involved in high glucose (HG)-induced tubular cells injury, characterized by activation of Gasdermin D (GSDMD) and the release of IL-1ß and IL-18, resulting in inflammatory injury in DN. It is reasonable to assume that ALPK1 is involved in pyroptosis-related tubular injury in DN. However, the mechanism remains poorly defined. METHODS: Immunohistochemistry (IHC) staining was performed to detect the expression of pyroptosis- and fibrosis-related proteins in renal sections of DN patients and DN mice. DN models were induced through injection of streptozotocin combined with a high-fat diet. Protein levels of ALPK1, NF-κB, Caspase-1, GSDMD, IL-1ß, IL-18 and α-SMA were detected by Western blot. HK-2 cells treated with high-glucose (HG) served as an in vitro model. ALPK1 small interfering RNA (siRNA) was transfected into HK-2 cells to down-regulate ALPK1. The pyroptosis rates were determined by flow cytometry. The concentrations of IL-1ß and IL-18 were evaluated by ELISA kits. Immunofluorescence staining was used to observe translocation of NF-κB and GSDMD. RESULTS: The heat map of differentially expressed genes showed that ALPK1, Caspase-1 and GSDMD were upregulated in the DN group. The expression levels of ALPK1, Caspase-1, GSDMD and CD68 were increased in renal biopsy tissues of DN patients by IHC. ALPK1expression and CD68+ macrophages were positively correlated with tubular injury in DN patients. Western blot analysis showed increased expressions of ALPK1, phospho-NF-κB P65, GSDMD-NT, and IL-1ß in renal tissues of DN mice and HK-2 cells, accompanied with increased renal fibrosis-related proteins (FN, α-SMA) and macrophages infiltration in interstitial areas. Inhibition of ALPK1 attenuated HG-induced upregulation expressions of NF-κB, pyroptosis-related proteins Caspase-1, GSDMD-NT, IL-1ß, IL-18, α-SMA, and pyroptosis level in HK-2 cells. Also, the intensity and nuclear translocation of NF-κB and membranous translocation of GSDMD were ameliorated in HG-treated HK-2 cells after treatment with ALPK1 siRNA. CONCLUSIONS: Our data suggest that ALPK1/NF-κB pathway initiated canonical caspase-1-GSDMD pyroptosis pathway, resulting in tubular injury and interstitial inflammation of DN.

Puerarin protects renal ischemia-reperfusion injury in rats through NLRP3/Caspase-1/GSDMD pathway

Purpose: To observe the effect of puerarin on renal ischemia-reperfusion (I/R) injury in rats, and to explore its mechanism based on NLRP3/Caspase-1/GSDMD pathway. Methods: Twenty-one Sprague-Dawley rats were divided into three groups: sham-operated group (sham), model group (RIRI), and puerarin treatment group (RIRI + Pue). The model of acute renal I/R injury was established by cutting the right kidney and clamping the left renal pedicle for 45 min. Results: Renal function parameters were statistically significant in group comparisons. The renal tissue structure of rats in sham group was basically normal. Pathological changes were observed in the RIRI group. The renal pathological damage score and apoptosis rate in the RIRI group were higher than those in the sham group, and significantly lower in the RIRI + Pue group than in the RIRI group. Indicators of oxidative stress-superoxide dismutase, malondialdehyde, and glutathione peroxidase-were statistically significant in group comparisons. Compared with the sham group, the relative expressions of NLRP3, Caspase-1 and GSDMD proteins in the RIRI group were increased. Compared with the RIRI group, the RIRI + Pue group had significant reductions. Conclusions: Puerarin can inhibit the activation of NLRP3/Caspase-1/GSDMD pathway, inhibit inflammatory response and pyroptosis, and enhance the antioxidant capacity of kidney, thereby protecting renal I/R injury in rats.

Progress of Different Programmed Cell Death Pathways in Kidney Cancer / 肿瘤防治研究

Programmed cell death (PCD) is a genetically determined, active and orderly cell death in the organism, and it affects the evolution of the organism, maintenance of its homeostasis, and development of several tissues and organs. The abnormal regulation of this process is closely related to various human diseases, including cancer. The identified pathways of PCD include apoptosis, autophagy, necroptosis, pyroptosis, and ferroptosis, which can be activated when cells are stimulated by various internal and external environmental factors. These pathways can induce cell death or maintain cell survival in kidney cancer cells under the regulation of various signaling molecules, thus affecting tumor progression or therapeutic efficacy. In this paper, the role of these PCD pathways in the development of kidney cancer was reviewed in light of recent research advances to provide new directions for the in-depth study of the pathogenesis of kidney cancer and the development of targeted antitumor drugs.

Maresin1 inhibits the NF-κB/caspase-3/GSDME signaling pathway to alleviate hepatic ischemia-reperfusion injury / 中华肝脏病杂志

Objective: To investigate the role of Maresin1 (MaR1) in hepatic ischemia-reperfusion injury (HIRI). Methods: The HIRI model was established and randomly divided into a sham operation group (Sham group), an ischemia-reperfusion group (IR group), and a MaR1 ischemia-reperfusion group (MaR1+IR group). MaR1 80ng was intravenously injected into each mouse's tail veins 0.5h before anesthesia. The left and middle hepatic lobe arteries and portal veins were opened and clamped. The blood supply was restored after 1h of ischemia. After 6h of reperfusion, the mice were sacrificed to collect blood and liver tissue samples. The Sham's group abdominal wall was only opened and closed. RAW267.4 macrophages were administered with MaR1 50ng/ml 0.5h before hypoxia, followed by hypoxia for 8h and reoxygenation for 2h, and were divided into the control group, the hypoxia-reoxygenation group (HR group), the MaR1 hypoxia-reoxygenation group (MaR1 + HR group), the Z-DEVD-FMK hypoxia-reoxygenation group (HR+Z group), the MaR1 + Z-DEVD-FMK hypoxia-reoxygenation group (MaR1 + HR + Z group), and the Con group without any treatment. Cells and the supernatant above them were collected. One-way analysis of variance was used for inter-group comparisons, and the LSD-t test was used for pairwise comparisons. Results: Compared with the Sham group, the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), interleukin (IL)-1β, and IL-18 in the IR group were significantly higher (P < 0.05), with remarkable pathological changes, while the level in the MaR1 + IR group was lower than before (P < 0.05), and the pathological changes were alleviated. Compared with the Con group, the HR group had higher levels of IL-1β and IL-18 (P < 0.05), while the MaR1 + HR group had lower levels of IL-1β and IL-18 (P < 0.05). Western blot showed that the expressions of caspase-3, GSDME, and GSDME-N were significantly higher in the HR group and IR group than in the other groups; however, the expression was lower following MaR1 pretreatment. The Z-DEVD-FMK exploration mechanism was inhibited by the expression of caspase-3 in HIRI when using MaR1. Compared with the HR group, the IL-1β and IL-18 levels and the expressions of caspase-3, GSDME, and GSDME-N in the HR + Z group were decreased (P < 0.05), while the expression of nuclear factor κB was increased, but following MaR1 pretreatment, nuclear factor κB was decreased. There was no significant difference in the results between the MaR1 + H/R group and the MaR1 + H/R + Z group (P > 0.05). Conclusion: MaR1 alleviates HIRI by inhibiting NF-κB activation and caspase-3/GSDME-mediated inflammatory responses.

Construction of a prognostic model for hepatocellular carcinoma based on pyroptosis-related genes / 中华肝脏病杂志

Objective: To study the construction of a prognostic model for hepatocellular carcinoma (HCC) based on pyroptosis-related genes (PRGs). Methods: HCC patient datasets were obtained from the Cancer Genome Atlas (TCGA) database, and a prognostic model was constructed by applying univariate Cox and least absolute shrinkages and selection operator (LASSO) regression analysis. According to the median risk score, HCC patients in the TCGA dataset were divided into high-risk and low-risk groups. Kaplan-Meier survival analysis, receiver operating characteristic (ROC) curves, univariate and multivariate Cox analysis, and nomograms were used to evaluate the predictive ability of the prognostic models. Functional enrichment analysis and immune infiltration analysis were performed on differentially expressed genes between the two groups. Finally, two HCC datasets (GSE76427 and GSE54236) from the Gene Expression Omnibus database were used to externally validate the prognostic value of the model. Univariate and multivariate Cox regression analysis or Wilcoxon tests were performed on the data. Results: A total of 366 HCC patients were included after screening the HCC patient dataset obtained from the TCGA database. A prognostic model related to HCC was established using univariate Cox regression analysis, LASSO regression analysis, and seven genes (CASP8, GPX4, GSDME, NLRC4, NLRP6, NOD2, and SCAF11). 366 cases were evenly divided into high-risk and low-risk groups based on the median risk score. Kaplan-Meier survival analysis showed that there were statistically significant differences in the survival time between patients in the high-risk and low-risk groups in the TCGA, GSE76427, and GSE54236 datasets (median overall survival time was 1 149 d vs. 2 131 d, 4.8 years vs. 6.3 years, and 20 months vs. 28 months, with P = 0.000 8, 0.034 0, and 0.0018, respectively). ROC curves showed good survival predictive value in both the TCGA dataset and two externally validated datasets. The areas under the ROC curves of 1, 2, and 3 years were 0.719, 0.65, and 0.657, respectively. Multivariate Cox regression analysis showed that the risk score of the prognostic model was an independent predictor of overall survival time in HCC patients. The risk model score accurately predicted the survival probability of HCC patients according to the established nomogram. Functional enrichment analysis and immune infiltration analysis showed that the immune status of the high-risk group was significantly decreased. Conclusion: The prognostic model constructed in this study based on seven PRGs accurately predicts the prognosis of HCC patients.

Associations of genetic variations in pyroptosis related genes with acute adverse events in postoperative rectal cancer patients receiving concurrent chemoradiotherapy / 中华肿瘤杂志

Objective: This study aims to investigate the associations between genetic variations of pyroptosis pathway related key genes and adverse events (AEs) of postoperative chemoradiotherapy (CRT) in patients with rectal cancer. Methods: DNA was extracted from the peripheral blood which was collected from 347 patients before CRT. Sequenom MassARRAY was used to detect the genotypes of 43 haplotype-tagging single nucleotide polymorphisms (htSNPs) in eight pyroptosis genes, including absent in melanoma 2 (AIM2), caspase-1 (CASP1), caspase-4(CASP4), caspase-5 (CASP5), caspase-11 (CASP11), gasdermin D (GSDMD), gasdermin E (GSDME) and NLR family pyrin domain containing 3 (NLRP3). The associations between 43 htSNPs and AEs were evaluated by the odd ratios (ORs) and 95% confidence intervals (CIs) by unconditional logistic regression models, adjusted for sex, age, clinical stage, tumor grade, Karnofsky performance status (KPS), surgical procedure, and tumor location. Results: Among the 347 patients with rectal cancer underwent concurrent CRT with capecitabine after surgery, a total of 101(29.1%) occurred grade ≥ 2 leukopenia. rs11226565 (OR=0.41, 95% CI: 0.21-0.79, P=0.008), rs579408(OR=1.54, 95% CI: 1.03-2.29, P=0.034) and rs543923 (OR=0.63, 95% CI: 0.41-0.98, P=0.040) were significantly associated with the occurrence of grade ≥ 2 leukopenia. One hundred and fifty-six (45.0%) had grade ≥ 2 diarrhea, two SNPs were significantly associated with the occurrence of grade ≥ diarrhea, including CASP11 rs10880868 (OR=0.55, 95% CI: 0.33-0.91, P=0.020) and GSDME rs2954558 (OR=1.52, 95% CI: 1.01-2.31, P=0.050). In addition, sixty-six cases (19.0%) developed grade ≥2 dermatitis, three SNPs that significantly associated with the risk of grade ≥2 dermatitis included GSDME rs2237314 (OR=0.36, 95% CI: 0.16-0.83, P=0.017), GSDME rs12540919 (OR=0.52, 95% CI: 0.27-0.99, P=0.045) and NLRP3 rs3806268 (OR=1.51, 95% CI: 1.03-2.22, P=0.037). There was no significant difference in the association between other genetic variations and AEs of rectal cancer patients (all P>0.05). Surgical procedure and tumor location had great impacts on the occurrence of grade ≥2 diarrhea and dermatitis (all P<0.01). Conclusion: The genetic variants of CASP4, CASP11, GSDME and NLRP3 are associated with the occurrence of AEs in patients with rectal cancer who received postoperative CRT, suggesting they may be potential genetic markers in predicting the grade of AEs to achieve individualized treatment of rectal cancer.

Effect of Baicalin on Pyroptosis of Diffuse Large B-Cell Lymphoma Cell Lines DB and Its Mechanism / 中国实验血液学杂志

OBJECTIVE@#To investigate the effect of Baicalin on the proliferation and pyroptosis of diffuse large B-cell lymphoma cell line DB and its mechanism.@*METHODS@#DB cells were treated with baicalin at different concentrations (0, 5, 10, 20, 40 μmol/L). Cell proliferation was detected by CCK-8 assay and half maximal inhibitory concentration (IC50) was calculated. The morphology of pyroptosis was observed under an inverted microscope, the integrity of the cell membrane was verified by LDH content release assay, and the expressions of pyroptosis-related mRNA and protein (NLRP3, GSDMD, GSDME, N-GSDMD, N-GSDME) were detected by real-time fluorescence quantitative PCR and Western blot. In order to further clarify the relationship between baicalin-induced pyroptosis and ROS production in DB cells, DB cells were divided into control group, baicalin group, NAC group and NAC combined with baicalin group. DB cells in the NAC group were pretreated with ROS inhibitor N-acetylcysteine (NAC) 2 mmol/L for 2 h. Baicalin was added to the combined treatment group after pretreatment, and the content of reactive oxygen species (ROS) in the cells was detected by DCFH-DA method after 48 hours of culture.@*RESULTS@#Baicalin inhibited the proliferation of DB cells in a dose-dependent manner (r=-0.99), and the IC50 was 20.56 μmol/L at 48 h. The morphological changes of pyroptosis in DB cells were observed under inverted microscope. Compared with the control group, the release of LDH in the baicalin group was significantly increased (P<0.01), indicating the loss of cell membrane integrity. Baicalin dose-dependently increased the expression levels of NLRP3, N-GSDMD, and N-GSDME mRNA and protein in the pyroptosis pathway (P<0.05). Compared with the control group, the level of ROS in the baicalin group was significantly increased (P<0.05), and the content of ROS in the NAC group was significantly decreased (P<0.05). Compared with the NAC group, the content of ROS in the NAC + baicalin group was increased. Baicalin significantly attenuated the inhibitory effect of NAC on ROS production (P<0.05). Similarly, Western blot results showed that compared with the control group, the expression levels of pyroptosis-related proteins was increased in the baicalin group (P<0.05). NAC inhibited the expression of NLRP3 and reduced the cleavage of N-GSDMD and N-GSDME (P<0.05). Compared with the NAC group, the NAC + baicalin group had significantly increased expression of pyroptosis-related proteins. These results indicate that baicalin can effectively induce pyroptosis in DB cells and reverse the inhibitory effect of NAC on ROS production.@*CONCLUSION@#Baicalin can inhibit the proliferation of DLBCL cell line DB, and its mechanism may be through regulating ROS production to affect the pyroptosis pathway.

Metformin inhibiting the activation of NLRP3 inflammasome and pyroptosis in diabetic retinal vascular endothelial cells / 中华眼底病杂志

Objective:To observe the effect of metformin (Met) on inflammatory bodies and focal death in human retinal microvascular endothelial cells (hRMEC) in diabetes mellitus (DM) microenvironment.Methods:Experimental research was divided into in vivo animal experiment and in vitro cell experiment. In vivo animal experiments: 9 healthy C57BL/6J male mice were randomly divided into DM group, normal control group, and DM+Met group, with 3 mice in each group. DM group and DM+Met group mice were induced by streptozotocin to establish DM model, and DM+Met group was given Met 400 mg/ (kg · d) intervention. Eight weeks after modeling, the expression of NLRP3, cleaved-membrane perforating protein D (GSDMD) and cleaved-Caspase-1 in the retina of mice in the normal control group, DM group and DM+Met group were observed by immunohistochemical staining. In vitro cell experiments: hRMEC was divided into conventional culture cell group (N group), advanced glycation end products (AGE) group, and AGE+Met group. Joining the AGE, AGE+Met groups cells were induced by 150 μg/ml of glycation end products, and 2.0 mmol/L Met was added to the AGE+Met group. Pyroptosis was detected by flow cytometry; 2' ,7'-dichlorofluorescein diacetate (DCFH-DA) fluorescent probe was used to detect the expression of reactive oxygen species (ROS) in cells of each group. Real-time fluorescence quantitative polymerase chain reaction and Western blot were used to detect the relative mRNA and protein expression levels of NLRP3, cleaved-GSDMD, cleaved-Caspase-1 in each group of cells. Single factor analysis of variance was used for comparison among the three groups.Results:In vivo animal experiments: compared with the DM group, the expression of NLRP3, cleaved-GSDMD, and cleaved-Caspase-1 in the retina of normal control group and DM+Met group mice was significantly reduced, with significant difference among the 3 groups ( F=43.478, 36.643, 24.464; P<0.01). In vitro cell experiment and flow cytometry showed that the pyroptosis rate of AGE group was significantly higher than that of N group and AGE+Met group ( F=32.598, P<0.01). The DCFH-DA detection results showed that the intracellular ROS levels in the N group and AGE+Met group were significantly lower than those in the AGE group, with the significant difference ( F=47.267, P<0.01). The mRNA ( F=51.563, 32.192, 44.473; P<0.01) and protein levels ( F=63.372, 54.463, 48.412; P<0.01) of NLRP3, cleaved-GSDMD, and cleaved-Caspase-1 in hRMEC of the AGE+Met group were significantly reduced compared to the N group. Conclusion:Met can down regulate the expression of NLRP3 inflammatory body related factors in hRMEC and inhibit pyroptosis.