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ObjectiveBased on tumor necrosis factor alpha （TNF-α）/tumor necrosis factor receptor 1 （TNFR1）/receptor-interacting protein kinases （RIPKs） signaling pathway， this paper aims to study the effect of modified Erchentang on inflammation in rats with chronic obstructive pulmonary disease （COPD） and explore its mechanism of action. MethodA total of 60 SD rats were randomly divided into normal group， model group， high， medium， and low-dose groups （20， 10， 5 g·kg-1·d-1） of modified Erchentang， and Xiaokechuan group （3.5 mL·kg-1·d-1）， with 10 rats in each group. The COPD rat model was established by cigarette smoke combined with lipopolysaccharide （LPS）. The normal group and model group were given the same amount of normal saline for 21 days by gavage administration. The contents of TNF-α and TNFR1 in bronchoalveolar lavage fluid （BALF） of rats were detected by enzyme-linked immunosorbent assay （ELISA）. Real-time fluorescence quantitative polymerase chain reaction （Real-time PCR） was used to detect mRNA expressions of RIPK1， RIPK3， and mixed lineage kinase domain-like （MLKL） in the lung tissue. The protein expressions of RIPK1， RIPK3， and MLKL in the lung tissue were detected by Western blot. The pathological changes in lung tissue were observed by hematoxylin-eosin （HE） staining. ResultCompared with the normal group， the contents of TNF-α and TNFR1 in BALF of the model group were significantly increased （P<0.01）， and the mRNA and protein expression levels of RIPK1， RIPK3， and MLKL in the lung tissue were significantly increased （P<0.01）. Compared with the model group， the contents of TNF-α and TNFR1 in BALF of high， medium， and low-dose groups of modified Erchentang and Xiaokechuan group were decreased （P<0.01）. The mRNA and protein expression levels of RIPK1， RIPK3， and MLKL in the lung tissue were decreased to different degrees （P<0.05， P<0.01）. ConclusionModified Erchentang can effectively improve the inflammatory response of lung tissue in COPD rats， and the mechanism may be by inhibiting the activation of the TNF-α/TNFR1/RIPKs signaling pathway.
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OBJECTIVE To study the effects and potential mechanism of wogonin （Wog） on airway inflammation in rats with chronic obstructive pulmonary disease （COPD）. METHODS Eighty-four rats were randomly divided into control group， model group， Wog low-dose and high-dose groups （intragastric administration of 50， 100 mg/kg）， aminophylline group （positive control， intragastric administration of 2.3 mg/kg）， recombinant rat receptor-interacting protein kinase 1 [rRIPK1， receptor-interacting protein kinase 1 （RIPK1） activator] group （tail vein injection of 8 µg/kg）， and Wog high-dose+rRIPK1 group （intragastric administration of Wog 100 mg/kg+tail vein injection of rRIPK 8 µg/kg）， with 12 rats in each group. Except for control group， COPD model of other groups was induced by smoking combined with tracheal injection of lipopolysaccharide. Twenty-four hours after successful modeling， the rats were administered once a day for 4 weeks. The changes of peak inspiratory flow （PIF）， peak expiratory flow （PEF） and minute ventilation （MV），forced expiratory volume in one second（FEV1）/forced vital capacity（FVC） were measured after the last medication； the serum levels of interleukin 1β（IL-1β）， IL-6 and tumor necrosis factor-α （TNF-α） were measured by ELISA； the pathological changes of lung tissue in rats were observed； the apoptotic rate of pulmonary epithelial cells was detected. mRNA expressions of RIPK1， RIPK3 and mixed lineage kinase domain-like protein （MLKL）， and protein expressions of RIPK1， RIPK3 and p-MLKL were all detected in lung tissue of rats. RESULTS Compared with control group， PIF， PEF， MV and FEV1/FVC of model group were decreased significantly （P＜0.05）， while the levels of IL-1β， IL-6 and TNF- α were increased significantly （P＜0.05）； there was a large number of inflammatory cells infiltration in the lung tissue and bronchialwall thickening in model group； the apoptotic rate of pulmonary epithelial cells，mRNA expressions of RIPK1， RIPK3 and MLKL， protein expressions of RIPK1， RIPK3 and p-MLKL were increased significantly （P＜0.05）. Compared with model group， above indexes of rats were improved significantly in Wog low-dose and high-dose groups （P＜0.05）， and pathological injuries were alleviated significantly. The corresponding indexes of rats were worsened in rRIPK1 group （P＜0.05）， and pathological damage had further worsened. rRIPK1 significantly attenuated the inhibitory effect of high-dose Wog on airway inflammation and RIPK1/RIPK3/ MLKL pathway in COPD rats （P＜0.05）. CONCLUSIONS Wog may improve airway inflammation in COPD rats by inhibiting RIPK1/RIPK3/MLKL signal pathway.
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Nucleotide-binding oligomerization domain containing protein 2 (NOD2) is a member of intracellular pattern recognition receptor. After being activated, it will induce the release of inflammatory factors through a series of signal cascade transduction, thus playing an important role in the innate immune response. The abnormal NOD2 signaling pathway is involved in the occurrence and development of many diseases, especially the single nucleotide polymorphisms (SNPs) of the NOD2 gene have been identified to be closely associated with autoinflammatory diseases (AIDs). Therefore, inhibitors targeting NOD2 pathway have great potential in the treatment of inflammatory immune diseases. This review presents the recent progress of NOD2 receptor-mediated signal transduction pathways and its regulation mechanisms, the relationship between NOD2 and AIDs, and the inhibitors of NOD2 pathway.
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Objective:To study the changes of plasma receptor interacting protein 3 (RIP3) levels in neonatal late-onset sepsis (LOS) and to determine its clinical value.Methods:From October 2019 to April 2021, plasma samples and clinical data of LOS infants admitted to our hospital were prospectively studied. Infants with similar gestational ages admitted for non-infectious diseases were assigned into the control group. Enzyme-linked immunoassay was used to determine plasma RIP3 levels. The clinical value of plasma RIP3 in the diagnosis and treatment of neonatal LOS were analyzed.Results:A total of 152 cases (76 in the LOS group and 76 in the control group) were included in the study. No significant differences existed in the baseline data between the two groups. A total of 226 plasma samples were collected (76 samples from the LOS group before treatment, 74 samples after treatment and 76 samples from the control group). The plasma RIP3 level of LOS group before treatment (19.9±6.3 ng/ml) was significantly higher than the control group (11.4±3.5 ng/ml) and the after treatment group (11.9±3.5 ng/ml) ( P<0.05). The plasma RIP3 level had good diagnostic value for neonatal LOS (AUC=0.884). With cut-off value of 15.5 ng/ml, the plasma RIP3 showed the best diagnostic efficacy (Youden index 0.658, sensitivity 72.4%, specificity 93.4%, positive likelihood ratio 11.0, negative likelihood ratio 0.3). Conclusions:Plasma RIP3 level is closely related with neonatal LOS and may be used for the early diagnosis and therapeutic evaluation of neonatal LOS.
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The morbidity of inflammatory bowel diseases (IBD) is rising rapidly but no curative therapies to prevent its recurrence. Cell death is crucial to maintaining homeostasis. Necroptosis is a newly identified programmed cell death and its roles played in IBD need to be explored. Necroptosis is mediated by receptor interacting protein kinase 1 (RIPK1), RIPK3, and mixed lineage kinase domain-like protein (MLKL), which resulted in cell swelling, plasma membrane rupture, intracellular content leaking, and eventually cell death as well as the promotion of inflammation. Studies have found that inhibiting necroptosis alleviated IBD in animal models and IBD patients with an increased level of necroptosis in inflammatory tissues, indicating that necroptosis is related to the pathogenesis of IBD. However, due to the complexity in regulation of necroptosis and the involvement of multiple functions of relevant signaling molecules, the specific mechanism remains elusive. Necroptosis may play a vital regulatory role in the pathogenesis of IBD, which provides a new idea and method for further exploring the therapeutic target of IBD.
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ObjectiveTo observe the effect of Danggui Buxuetang on the podocyte injury and receptor-interacting protein kinase 1/receptor-interacting protein kinase3/mixed lineage kinase domain-like protein （RIPK1/RIPK3/MLKL） signaling pathway in diabetic kidney disease （DKD） ratsand to explore its possible mechanism against DKD. MethodEight of the 50 SD rats were randomly classified intoa normal group， and the remaining were fed a high-glucose and high-fat diet for six weeks and then intraperitoneally injected with 0.035 g·kg-1streptozotocin （STZ） for inducing type 2 diabetes. After successful modeling，they were randomized into the model group，high- and low-dose （1.44，0.72 g·kg-1） Danggui Buxuetang groups， and irbesartan （0.017 g·kg-1）group. After 20 weeks of drug intervention， the fasting blood glucose （FBG）， kidney index （KI），and urinary microalbumin-to-urine creatinine ratio （UACR）were detected in each group. The pathological changes in renal tissue were observed by hematoxylin-eosin （HE） staining， followed by the observation of ultrastructural changes in podocytes under the transmission electron microscope. The levels of tumor necrosis factor-α （TNF-α） and interleukin-6 （IL-6） in renal tissue of rats were determined by enzyme-linked immunosorbent assay （ELISA）， and the protein expression levels of RIPK1， RIPK3， and MLKL in rat kidney tissue by immunohistochemistry. The apoptosis rate of podocytes was detected by in situ nick end-labeling （TUNEL） assay. The mRNA expression levels of RIPK1， RIPK3， and MLKL in kidney tissue of rats were measured by real-time fluorescence quantitative polymerase chain reaction （Real-time PCR）， and the protein expression levels of RIPK， RIPK3， and MLKL and podocyte marker Wilms tumor protein-1 （WT-1） in rat kidney tissue were assayed by Western blot. ResultCompared with the normal group， the model group exhibited elevated FBG， UACR， and KI （P<0.01）， glomerular hypertrophy， thickened basement membrane， increased extracellular matrix， mesangial hyperplasia， foot process fusion or loss， enhanced apoptosis in renal tissue， up-regulated TNF-α and IL-6 levels （P<0.01） and RIPK1/RIPK3/MLKL mRNA and protein expression （P<0.01）， and down-regulated WT-1 protein expression. Compared with the model group， Danggui Buxuetang high-dose group significantly reduced the levels of FBG， UACR， and KI， improved renal histopathology， podocyte loss， and apoptosis in renal tissue， down-regulated TNF-α and IL-6 levels and RIPK1/RIPK3/MLKL mRNA and protein expression （P<0.05， P<0.01）， and up-regulated WT-1 protein expression. ConclusionDanggui Buxuetang alleviates podocyte injury and delays the development of DKD possibly by regulating the RIPK1/RIPK3/MLKL signaling pathway.
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Objective:To explore the level of expression, clinical significance of receptor-interacting protein kinase-3(RIPK3) in the bronchoalveolar alveolar lavage fluid (BALF) of mycoplasma pneumoniae pneumonia(MPP) in children and the relationship between RIPK3 and various cytokines.Methods:Using a case-control study, 30 refractory mycoplasma pneumoniae pneumonia children treated in Children′s Hospital of Xuzhou Medical University from February 2019 to February 2021 were selected as the MRPP group, 35 mycoplasma pneumoniae pneumonia children as the RPP group.Meanwhile, 20 sex- and age-matched hospitalized children with bronchial foreign body were selected as the case-control group.In all subjects, protein levels of RIPK3 and mixed lineage kinase domain-like protein(MLKL) were determined by Western Blot.Meanwhile, levels of IL-6, IL-1β and TNF-α were determined by enzyme linked immuno sorbent assay(ELISA). Compare levels of different parameters between the three groups and analyze the correlation between levels of RIPK3 and MLKL, L-6, IL-1β, TNF-α in the BALF of MPP children using Spearman rank correlation analysis.Results:There were statistically significant differences in the levels of RIPK3, MLKL, IL-6, IL-1β and TNF-α in BALF between RMPP group, MPP group and control group (all P<0.001). Pairwise comparisons also showed statistical differences, and the RMPP group was the highest, followed by MPP group, and the control group was the lowest.The level of RIPK3 in BALF of MPP children was positively correlated with MLKL, IL-6, IL-1β and TNF-α ( r=0.711, 0.676, 0.725, 0.651, P<0.001). Linear regression analysis shows: MLKL=0.432×RIPK3. Conclusion:RIPK3 may be involved in the occurrence and development of MPP in children, and is closely related to cytokines such as IL-6, IL-1β and TNF-α.
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Osteoarthritis (OA) is the most common chronic disabling joint disease, and currently there is no effective treatment for the cause. Necroptosis plays a key role in many diseases, and receptor-interacting protein kinase 3 (RIP3) is a key regulator during necroptosis process. Studies have shown that the expression level of RIP3 was significantly upregulated in human and mouse OA degenerative cartilage tissues, suggesting the occurrence of necroptosis. However, the specific pathophysiological role of RIP3 in cartilage is still unclear. This study intends to sequence and analyze the transcriptome of chondrocytes before and after RIP3 overexpression, and explore the specific functional mechanism of RIP3 in OA pathogenesis. RNA sequencing results showed that overexpression of RIP3 induced upregulation of 244 genes and downregulation of 277 genes in chondrocytes. Sixteen candidate target genes were screened out by constructing gene co-expression network for further verification at mRNA level, and the results suggested that RIP3 had the most significant inductive effect on the expression of phosphoinositide-3kinase, regulatory subunit 5 (Pik3r5), integrin subunit beta 3 (Itgb3) and MYB proto-oncogene like 2 (Mybl2). Results from CCK-8 and lactate dehydrogenase activity analysis showed that silencing the expression of Itgb3 by siRNA significantly rescued chondrocyte viability decline and necroptosis induced by RIP3, and it also inhibited the upregulating effect of RIP3 on the expression of catabolism-related genes Mmp1, Mmp13 and Il6, as well as the downregulating effect of RIP3 on the expression of anabolism-related genes Acan, Col2a1 and Sox9. This study has demonstrated that RIP3 promotes chondrocyte necrosis and cartilage matrix metabolism disorders by upregulating the expression of Itgb3 in chondrocytes, and ultimately leads to cartilage degeneration. These findings provided potential novel targets for the clinical treatment of OA, and further clarified the pathophysiological significance of necroptosis.
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Objective To investigate the lethal effect of melittin on human hepatocellular carcinoma cell line SMMC-7721 and its possible mechanism. Methods MTT assay was used to investigate the killing effect of different concentrations melittin on human hepatocellular carcinoma cells SMMC-7721. Meanwhile, the inhibitory effect of specific programmed necrosis inhibitors necrostain-1(Nec-1) on melittin killing SMMC-7721 cells was detected. Programmed cell necrosis observed by Hoechst 33342 and PI double staining. The necrotosis rate was detected by flow cytometry. Ultrastructural changes of cell was detected by transmission electron microscopy. The expression of receptor interacting protein 1(RIP1) was detected by Western blotting. Results Compared with the control group, the proliferation activity of SMMC-7721 cells was significantly decreased after treatment with different concentrations of melittin for 24 hours (P < 0. 05) . Cells stained in dark blue and red. Cell membrane integrity was destroyed, organelle swelling, organelle membrane was destroy, that demonstrates cell was necrosis. Westen blotting result showed an increased proportion of RIP1 expression in SMMC-7721 cells. Compared with the melittin group, cell proliferation activity was significantly increased, cell necrotosis rate was decreased, and intracellular RIP1 expression was down-regulated in the Nec-1 pretreatment group. Conclusion Melittin induces cell death in SMMC-7721 cells through the RIP1-mediated programmed necrosis pathway.
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Background Programmed necrosis is closely related to the occurrence and development of neurodegenerative diseases, but whether lead causes programmed cell necrosis has not been reported. Objective This experiment is designed to probe into the function of programmed necrosis and the effect of its inhibitor on lead-induced microglia (BV2 cell) injury. Methods The BV2 cells at logarithmic growth phase were treated with 0, 1, 5, 10, 25, 50, 100, and 200 μmol·L−1 lead acetate for 12, 24, 36, and 48 h, respectively, and methylthiazolyldiphenyl-tetrazolium bromide (MTT) was used to determine cell viability. After treatment with 0, 25, 50, and 100 μmol·L−1 lead acetate for 24 h, enzyme-linked immunosorbent assay, Western blotting, and flow cytometry were used to determine the expressions of tumor necrosis factor-α (TNF-α), receptor-interacting protein kinase 3 (RIPK3), receptor-interacting protein kinase 1 (RIPK1), and mixed lineage kinase domain-like protein (MLKL) in the cells, and the effect of RIPK1 inhibitor Nec-1 pretreatment on lead-induced BV2 cell injury . Results The BV2 cell viability decreased with higher lead concentration (r12 h=−0.995, r24 h=−0.984, r36 h=−0.983, r48 h=−0.981, all P<0.01) and time extension (only for 5 μmol·L−1 lead acetate, r=−0.994, P<0.01). Compared with the control group, the BV2 cell viability decreased at the same exposure time when the concentration of lead was above 10 μmol·L−1 (P<0.01). Compared with the control group, the expressions of RIPK1 and MLKL were increased in the 25, 50, and 100 μmol·L−1 lead groups (P<0.05 or 0.01), accompanied by an increase in the contents of inflammatory cytokine TNF-α, especially in the 100 μmol·L−1 lead group, the increment was the highest (P<0.01). The expression levels of p-RIPK1 and p-MLKL in BV2 cells were both increased when the concentration of lead acetate was above 50 μmol·L−1 (P<0.01). In addition, pretreatment with Nec-1 increased the cell viability rate and decreased the necrosis and late apoptosis rate of BV2 cells exposed to lead compared with corresponding lead exposure groups (P<0.05). Conclusions Lead can reduce BV2 cell viability, increase necrosis rate, and up-regulate the expressions of RIPK1, RIPK3, amd MLKL, and the phosphorylation levels of RIPK1 and MLKL. The RIPK1 inhibitor Nec-1 has an intervention effect on lead-induced damage in BV2 cells, indicating that programmed necrosis may play a role in lead neurotoxicity.
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OBJECTIVES@#To investigate the role and molecular mechanism of necrostatin-1 (Nec-1), a specific programmed cell necrosis inhibitor, in promoting the oxidative stress response of macrophages under high glucose (HG) environment.@*METHODS@#Macrophages were cultured in control (5.5 mmol·L@*RESULTS@#The HG group had increased ROS level and MDA activity (@*CONCLUSIONS@#HG promotes oxidative stress on macrophages by upregulating RIP1 expression.
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Humans , Glucose , Macrophages , Necrosis , Oxidative Stress , Reactive Oxygen SpeciesABSTRACT
Objective:To investigate the role of receptor-interacting protein kinse3 (RIPK3)-mediated necroptosis in diabetic mellitus-caused abolition of cardioprotection induced by sevoflurane postconditioning in rats.Methods:Eighty rats with diabetes mellitus, aged 4-5 weeks, weighing 90-100 g, were divided into 4 groups ( n=20 each) using a random number table method: sham operation group (group Sham), myocardial ischemia-reperfusion (I/R) group (group I/R), sevoflurane postconditioning group (group SP) and sevoflurane postconditiong plus RIPK3 inhibitor GSK-872 group (group GSK). Myocardial I/R was induced by 40 min occlusion of the left anterior descending branch of the coronary artery followed by 120 min reperfusion.In group SP, 2.4% sevoflurane was inhaled for 15 min at the beginning of reperfusion.In group GSK, GSK-872 3.3 mg/kg (dissolved in normal saline) was intraperitoneally injected at 24 and 2 h before surgery, and the other treatments were similar to those previously described in group SP.After 120 min of reperfusion, blood samples from the abdominal aorta were collected for determination of concentrations of serum lactate dehydrogenase (LDH) and creatine kinase-MB (CK-MB). Myocardial tissues were taken for determination of percentage of myocardial infarct size (by TTC staining) and expression of RIPK3, phospho-Ca 2+ -calmodulin-dependent protein kinase Ⅱ (p-CaMKⅡ) and phospho-mixed lineage kinase domain-like protein (p-MLKL) (by Western blot), and the ultrastructure of myocardium was observed by transmission electron microscopy. Results:Compared with group Sham, the serum LDH and CK-MB concentrations and percentage of myocardial infarct size were significantly increased, the expression of RIPK3, p-MLKL and p-CaMKⅡ in myocardial tissues was up-regulated ( P<0.05), and the damage to cardiomyocytes was severe in group I/R.Compared with group I/R, no significant change was found in the parameters mentioned above in group SP ( P>0.05). Compared with group SP, the serum LDH and CK-MB concentrations and percentage of myocardial infarct size were significantly decreased, the expression of RIPK3, p-MLKL and p-CaMKⅡ in myocardial tissues was down-regulated ( P<0.05), and the damage to cardiomyocytes was reduced in group GSK. Conclusion:The mechanism of diabetic mellitus-caused abolition of cardioprotection induced by sevoflurane postconditioning is related to excessive activation of RIPK3-mediated necroptosis in rats.
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Necroptosis is a tightly regulated form of necrosis that requires the activation of receptor-interacting protein (RIP) kinases RIPK1 and RIPK3, as well as the RIPK3 substrate mixed lineage kinase domain-like protein (MLKL). Because of membrane rupture, necroptotic cells release damage-associated molecular patterns (DAMPs) that evoke immune responses. Necroptosis is emerging as an important cellular response in the modulation of cancer initiation, progression, and metastasis. Necroptosis of cancer cells is considered to be an immunogenic cell death capable of activating anti-tumor immunity. Necroptosis also participates in the promotion of myeloid cell-induced adaptive immune suppression and thus contributes to oncogenesis. In addition, necroptosis of endothelial cells and tumor cells is conducive to tumor metastasis. In this review, we summarize the current knowledge of the complex role of necroptosis in cancer and discuss the potential of targeting necroptosis components for cancer therapies.
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Objective:To explore the kinase activity of novel receptor interacting protein kinase 3 (RIPK3) mutants. Methods:The four amino acids (Q84WDF87) of RIPK3 were mutated respectively and these mutants were co-transfected with mixed lineage kinase domain like pseudokinase (MLKL) into HEK293T cells. The auto-phosphorylation of these mutants at S232 and phosphorylation of MLKL at S345 were detected by Western blotting. The interaction between RIPK3 and MLKL was tested by co-immunoprecipitation. The oligomerization of MLKL was detected by non-reducing gel. Results:The kinase activities of RIPK3ΔQ84, RIPK3ΔW85 and RIPK3ΔD86 were effectively decreased. Nevertheless, the kinase activities of RIPK3Q84A/RIPK3Q84E, RIPK3W85Y and RIPK3D86A/RIPK3D86Y did not change markedly. The auto-phosphorylation of RIPK3W85A at S232 was decreased without affecting phosphorylation and oligomerization of MLKL. Conclusion:The amino acid site Q84, W85 or D86 plays a critical role in RIPK3 kinase activity. The kinase activity of RIPK3W85A is decreased, but it does not affect MLKL.
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Necroptosis is a tightly regulated form of necrosis that requires the activation of receptor-interacting protein (RIP) kinases RIPK1 and RIPK3, as well as the RIPK3 substrate mixed lineage kinase domain-like protein (MLKL). Because of membrane rupture, necroptotic cells release damage-associated molecular patterns (DAMPs) that evoke immune responses. Necroptosis is emerging as an important cellular response in the modulation of cancer initiation, progression, and metastasis. Necroptosis of cancer cells is considered to be an immunogenic cell death capable of activating anti-tumor immunity. Necroptosis also participates in the promotion of myeloid cell-induced adaptive immune suppression and thus contributes to oncogenesis. In addition, necroptosis of endothelial cells and tumor cells is conducive to tumor metastasis. In this review, we summarize the current knowledge of the complex role of necroptosis in cancer and discuss the potential of targeting necroptosis components for cancer therapies.
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Background@#Necroptosis plays an important role in human atherosclerosis and atheroma development. Since receptor interacting protein kinase-3 (RIP3) acts as a key mediator of necroptosis, this study aimed to explore its relationship between plasma RIP3 levels and coronary artery disease (CAD) and discover a potential new biomarker for screening CAD subtypes and severity.@*Methods@#A total of 318 patients with CAD who had coronary angiography and 166 controls in Peking Union Medical College Hospital from September 2017 to January 2018 were enrolled in this study. Patients with CAD were divided into three subgroups: patients with stable coronary artery disease (SCAD), patients with unstable angina (UA), and patients with myocardial infarction (MI). The severity of atherosclerosis was determined by Gensini score (GSS). Logistic regression was used to determine the relationship between plasma RIP3 levels and CAD. The correlation between plasma RIP3 and GSS was calculated using multiple linear regression models.@*Results@#Overall, plasma RIP3 levels were significantly higher than serum RIP3 levels. Plasma RIP3 levels in patients with CAD were significantly higher than those in controls. Plasma RIP3 levels were strongly associated with CAD (odds ratio: 6.00, 95% confidence interval 3.04–11.81; P < 0.001). Plasma RIP3 levels increased linearly from controls to patients with SCAD, then patients with UA, and finally to patients with MI. We found a significantly positive correlation between proportion of cases of acute coronary syndrome in subjects and their plasma RIP3 level quartile. Plasma RIP3 levels were also associated with GSS (B 0.027; standard error 0.012; P < 0.05).@*Conclusions@#Plasma RIP3 levels were independently associated with CAD. Plasma RIP3 levels could potentially supplement clinical assessment to screen CAD and determine CAD severity.
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Objective To evaluate the relationship between mechanical ventilation-induced apoptosis in hippocampal neurons and mammalian taget of rapamycin ( mTOR) signaling pathway in mice. Methods Fifty healthy male C57BL∕6 mice, aged 8-10 weeks, weighing 20-25 g, were divided into 2 groups ( n=25 each) using a random number table method: control group ( group C ) and mechanical ventilation group ( group V) . The mice breathed spontaneously for 6 h in group C, and the mice were mechanically ventilated for 6 h in group V. Open field test and contextual fear conditioning test were conducted at 1 and 3 days after the end of ventilation. Hippocampal tissues were obtained at 1 day after the end of ventilation for determina-tion of the expression of mTOR, phosphorylated mTOR (p-mTOR), microtubule-associated protein 1 light chain 3Ⅱ( by Western blot) and apoptosis in hippocampal neurons ( by TUNEL) . The p-mTOR∕mTOR ratio and apoptosis index were calculated. Results Compared with group C, the time animals spent in the central square was significantly prolonged, the number of crossing the grid was reduced, the percentage of freezing time was decreased, the expression of microtubule-associated protein 1 light chain 3Ⅱwas up-regulated, and the p-mTOR∕mTOR ratio and apoptosis index were increased in group V ( P<0. 05) . Conclusion The mech-anism by which mechanical ventilation induces apoptosis in hippocampal neurons may be related to activation of mTOR signaling pathway in mice.
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Myocardial ischemia/reperfusion (I/R) injury seriously endangers human health and is a potential hidden danger in the treatment of cardiovascular diseases, among which myocardial necrosis is one of the mechanisms of myocardial I/R injury. Numerous studies have shown that necrosis factor is widely involved in the regulation of myocardial cell necrosis, but its specific mechanism is not fully understood. Receptor interacting protein 3/receptor interacting protein kinase 3 (RIP3/RIPK3) is an essential protein in necroptosis pathways, and activated RIP3 can cause irreversible necrosis of myocardial cells. On the basis of introducing RIP3 molecule, this paper focused on the role and mechanism of RIP3 mediated necroptosis pathway in myocardial cell necroptosis, with a view to providenew ideas and insights for the treatment of myocardial I/R injury.
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Objective To explore the effects of bone marrow mesenchymal stem cells (MSCs) transplantation on receptor-interacting protein kinase 1 (RIP1) and RIP3 in rat brain after cardiac arrest (CA).Methods Sprague Dawley (SD) rats were randomly (random number) divided into sham group (n=8),CA group (n=8) and MSCs group (n=8).Animals were subjected to asphyxial cardiac arrest and followed by cardiopulmonary resuscitation (CPR).In MSCs group or CA group,animals received intravenous injection of 1 × 106 MSCs in 0.5 mL phosphate buffer solution (PBS) or 0.5 mL PBS alone at 1 h after successful resuscitation.Neurological deficit scores (NDS) were assessed at 3 d after CPR.Donor MSCs in brain were detected under a fluorescent microscope.HE staining of brain tissue was performed to observe necrotic neurons.Western blot analysis was performed to measure the levels of RIP1 and RIP3 in brain.Multiple comparisons were made by analysis of variance or Kruskal-Wallis H test.Results At 3 d after CPR,MSCs group demonstrated higher NDS than CA group [72.5(71.5,73.2) vs.63.0(62.5,64.1),Z=3.376,P=0.001].DAPI-labeled MSCs were primarily observed in the cerebral cortex.The percentage of necrotic neurons in MSCs group was significantly lower than that in CA group [(29.6±5.9)％ vs.(57.2±6.4)％,t=8.922,P＜0.01].The levels of RIP1 and RIP3 expression in brain in MSCs group were significantly lower than those in CA group [RIP1:0.227(0.193,0.243) vs.0.599(0.535,0.629),Z=3.151,P=0.001;RIP3:0.217(0.203,0.274) vs.0.543(0.533,0.555),Z=3.361,P=0.001].Conclusion MSCs transplantation improves neurological function after CPR from CA in rats likely associated with inhibiting necroptosis.
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Objective To evaluate the effect of dexmedetomidine on receptor-interacting protein 1 (RIP1) signaling pathway during brain injury after cardiac arrest and resuscitation in pigs.Methods Twenty-one healthy domestic male white pigs,weighing 33-41 kg,were divided into 3 groups (n =7 each) using a random number table method:sham operation group (group S),cardiac arrest-resuscitation group (group CA-R) and dexmedetomidine group (group D).Ventricular fibrillation was electrically induced and untreated for 8 min followed by 5 min of cardiopulmonary resuscitation to establish the model of brain injury after cardiac arrest and resuscitation in anesthetized domestic white pigs.Dexmedetomidine was infused via the femoral vein in a loading dose of 0.5 μg/kg at 5 min after successful resuscitation,followed by an infusion of 0.5 μg · kg-1 · h-1 for 6 h in group D.The equal volume of normal saline was given instead in S and CA-R groups.The concentrations of neuron-specific endase (NSE) and S-100β protein in serum were measured at 1,3,6 and 24 h after resuscitation (T1-4).Neurologic deficit score (NDS) was evaluated at T4.The animals were sacrificed at T4,brains were removed and cerebral cortex tissues were obtained for determination of the expression of RIP1,RIP3 and mixed lineage kinase domain-like protein (MLKL) by Western blot.Results Compared with group S,the serum concentrations of NSE and S-100β protein were significantly increased at T1-4,the NDS was increased at T4,and the expression of RIP1,R1P3 and MLKL in cerebral cortex tissues was up-regulated in CA-R and D groups (P＜0.05).Compared with group CA-R,the serum concentrations of NSE and S-100β protein were significantly decreased at T3,4,the NDS was decreased at T4,and the expression of RIP1,RIP3 and MLKL in cerebral cortex tissues was down-regulated in group D (P＜0.05).Conclusion The mechanism by which dexmedetomidine reduces brain injury after cardiac arrest and resuscitation may be related to inhibiting the activation of RIP 1 signaling pathway in pigs.