Necroptosis Signaling Pathway Research Articles

Selenium-Enriched Cardamine violifolia Alleviates LPS-Induced Hepatic Damage and Inflammation by Suppressing TLR4/NODs-Necroptosis Signal Axes in Piglets.

Selenium-enriched Cardamine violifolia (SEC), a cruciferous plant, exerts excellent antioxidant and anti-inflammatory capacity, but its effect on hepatic function is unclear. This study investigated the effect and potential mechanism of SEC on hepatic injury induced by lipopolysaccharide (LPS). Twenty-four weaned piglets were randomly allotted to treatment with SEC (0.3 mg/kgSe) and/or LPS (100 μg/kg). After 28 days of the trial, pigs were injected with LPS to induce hepatic injury. These results indicated that SEC supplementation attenuated LPS-induced hepatic morphological injury and reduced aspartate aminotransferase (AST) and alkaline phosphatase (ALP) activities in plasma. SEC also inhibited the expression of pro-inflammatory cytokines such as interleukin 6 (IL-6) and tumor necrosis factor-alpha (TNF-α) after the LPS challenge. In addition, SEC improved hepatic antioxidant capacity via enhancing glutathione peroxidase (GSH-Px) activity and decreasing malondialdehyde (MDA) concentration. Moreover, SEC downregulated the mRNA expression of hepatic myeloid differentiation factor 88 (MyD88) and nucleotide-binding oligomerization domain proteins 1 (NOD1) and its adaptor molecule receptor interacting protein kinase 2 (RIPK2). SEC also alleviated LPS-induced hepatic necroptosis by inhibiting RIPK1, RIPK3, and mixed-lineage kinase domain-like (MLKL) expression. These data suggest that SEC potentially mitigates LPS-induced hepatic injury via inhibiting Toll-like receptor 4 (TLR4)/NOD2 and necroptosis signaling pathways in weaned piglets.

Lipopolysaccharide and glycolipoprotein coordinately triggered necroptosis contributes to the pathogenesis of Leptospira infection in mice.

Leptospirosis is a recurring but neglected zoonotic disease caused by pathogenic Leptospira. The explicit underlying mechanism of necroptosis and its role in Leptospira infection have not yet been elucidated. Here we reported that leptospiral PAMPs, lipopolysaccharide and glycolipoprotein activated the necroptotic RIPK1-RIPK3-MLKL cascade through the TLR4 signaling pathway in mouse macrophages. Using the murine acute leptospirosis model, we revealed that abolition of necroptosis exhibited significantly improved outcomes in acute phases, with enhanced eradication of Leptospira from liver, mild clinical symptoms and decreased cytokine production. RIPK3 was also found to exert necroptosis-independent function in CXCL1 production and neutrophil recruitment, with the consequence of improved Leptospira control. These findings improved our understanding of the mechanism of Leptospira-macrophage interactions, indicating potential therapeutic values by targeting necroptosis signaling pathways.

Curcumin alleviates experimental colitis in mice by suppressing necroptosis of intestinal epithelial cells.

Curcumin, the primary bioactive substance in turmeric, exhibits potential therapeutic effects on ulcerative colitis. However, its mechanism for regulating necroptosis in colitis has not been fully elucidated. In this study, the effect of curcumin on experimental colitis-induced necroptosis of intestinal epithelial cells was investigated, and its molecular mechanism was further explored. We found that curcumin blocked necroptosis in a dose-dependent manner by inhibiting the phosphorylation of RIP3 and MLKL instead of RIP1 in HT-29 cells. Co-Immunoprecipitation assay showed that curcumin weakened the interaction between RIP1 and RIP3, possibly due to the direct binding of curcumin to RIP3 as suggested by drug affinity responsive target stability analysis. In a classical in vivo model of TNF-α and pan-caspase inhibitor-induced necroptosis in C57BL/6 mice, curcumin potently inhibited systemic inflammatory responses initiated by the necroptosis signaling pathway. Then, using a dextran sodium sulfate-induced colitis model in C57BL/6 mice, we found that curcumin inhibited the expression of p-RIP3 in the intestinal epithelium, reduced intestinal epithelial cells loss, improved the function of the intestinal tight junction barrier, and reduced local intestinal inflammation. Collectively, our findings suggest that curcumin is a potent targeted RIP3 inhibitor with anti-necroptotic and anti-inflammatory effects, maintains intestinal barrier function, and effectively alleviates colitis injury.

Rab7a-mTORC1 signaling-mediated cholesterol trafficking from the lysosome to mitochondria ameliorates hepatic lipotoxicity induced by aflatoxin B1 exposure

Aflatoxin B1 (AFB1) is a common contaminant in many foodstuffs and is considered a public health concern worldwide due to its hepatotoxicity caused by lipid metabolism disorders. However, the molecular mechanism underlying AFB1-induced lipotoxicity-dependent liver injury via regulating cholesterol metabolism remains unclear. We established a cholesterol trafficking disorder-mediated hepatic lipotoxicity model with AFB1 mixture exposure in vitro (HepaRG and HepG2 cells, 1.6 μM for 36 h) and in vivo (C57BL/6 mice, 3 mg kg−1, i.g., every other day for 6 weeks). In vitro, the interaction between lysosomal Niemann-Pick type C1 (NPC1) protein and mitochondrial translocator protein (TSPO) regulated lipotoxicity induced by AFB1 mixture exposure, including lysosomal membrane permeabilization and mitochondria-dependent necroptosis. Moreover, the downregulation of lysosomal Ras-associated protein 7a (Rab7a) enhanced the mammalian target of rapamycin complex 1 (mTORC1)-mediated disorders of cholesterol trafficking from the lysosome to mitochondria. Furthermore, cholesterol trafficking disorder-mediated hepatic lipotoxicity induced by the low-dose level of AFB1 exposure was relieved by genetic or pharmaceutic activation of Rab7a to inhibit mTORC1 in vitro and ex vivo. In vivo, mTORC1 inhibitor (Torin1, 4 mg kg−1, i.p., every other day for 3 weeks) alleviated the cholesterol trafficking disorder-mediated hepatic lipotoxicity via upregulating the molecular machinery of lysosomes and mitochondria contact mediated by NPC1 and TSPO interaction in the low dose of AFB1 exposure. Altogether, our data suggested a novel mechanism that lysosomal Rab7a-mTORC1 signaling determined the cholesterol trafficking regulated by NPC1-TSPO from the lysosome to mitochondria, which promoted hepatic lipotoxicity via lysosomal quality control and mitochondria-dependent necroptosis signaling pathways in chemical mixture exposure.

Bilateral varicocele leads to ferroptosis, pyroptosis and necroptosis of human spermatozoa and affects semen quality in infertile men.

Purpose: This study explored the effects of bilateral varicocele on male semen quality in infertile men and the molecular mechanisms involving ferroptosis, pyroptosis and necroptosis signaling pathways. Methods: Totally, 20 healthy males and 26 patients with bilateral varicocele receiving infertility treatment were enrolled. Semen samples were collected. Basic semen parameters, acrosome integrity and membrane integrity, mitochondrial membrane potential (MMP) and apoptosis rate were compared. Levels of reactive oxygen species (ROS), iron, glutathione (GSH), total superoxide dismutase (T-SOD), and, Catalase (CAT), were detected in human seminal plasma. Relative mRNA expression of Ca 2+-independent phospholipases A2 beta (iPLA 2β), P53, Zinc finger E-box binding homeobox 1 (ZEB1) and GSH-dependent peroxidase 4 (GPX4) were evaluated. Relative protein expression was determined for GPX4, receptor interacting serine/threonine kinase 1 (RIPK1) and receptor interacting serine/threonine kinase 3 (RIPK3), as well as pyroptosis markers of Gasdermin E (GSDME) and heat shock protein 90 (HSP 90). Results: The results revealed that the bilateral varicocele group had significantly higher abnormalities (sperm progressive rate and sperm motility) compared to the control group. Meanwhile, compared to control group, GSH, T-SOD, and CAT levels were reduced in the bilateral varicocele group (p < 0.05). However, the level of ROS and iron were significantly increased (p < 0.05). Relative mRNA expression of P53, iPLA 2β, ZEB1, and GPX4 were reduced. In addition, ROS exposure activated ferroptosis-related signal pathways. RIPK1, RIPK3, GSDME and HSP 90 were increased in bilateral varicocele group. ROS exposure affected signaling pathways related to ferroptosis, necrosis and pyroptosis in human spermatozoa. Conclusion: Bilateral varicocele leads to ferroptosis, pyroptosis and necroptosis of human spermatozoa and affects semen quality in infertile men.

Protocatechuic acid and quercetin attenuate ETEC-caused IPEC-1 cell inflammation and injury associated with inhibition of necroptosis and pyroptosis signaling pathways

BackgroundNecroptosis and pyroptosis are newly identified forms of programmed cell death, which play a vital role in development of many gastrointestinal disorders. Although plant polyphenols have been reported to protect intestinal health, it is still unclear whether there is a beneficial role of plant polyphenols in modulating necroptosis and pyroptosis in intestinal porcine epithelial cell line (IPEC-1) infected with enterotoxigenic Escherichia coli (ETEC) K88. This research was conducted to explore whether plant polyphenols including protocatechuic acid (PCA) and quercetin (Que), attenuated inflammation and injury of IPEC-1 caused by ETEC K88 through regulating necroptosis and pyroptosis signaling pathways.MethodsIPEC-1 cells were treated with PCA (40 μmol/L) or Que (10 μmol/L) in the presence or absence of ETEC K88.ResultsPCA and Que decreased ETEC K88 adhesion and endotoxin level (P < 0.05) in cell supernatant. PCA and Que increased cell number (P < 0.001) and decreased lactate dehydrogenases (LDH) activity (P < 0.05) in cell supernatant after ETEC infection. PCA and Que improved transepithelial electrical resistance (TEER) (P < 0.001) and reduced fluorescein isothiocyanate-labeled dextran (FD4) flux (P < 0.001), and enhanced membrane protein abundance of occludin, claudin-1 and ZO-1 (P < 0.05), and rescued distribution of these tight junction proteins (P < 0.05) after ETEC infection. PCA and Que also declined cell necrosis ratio (P < 0.05). PCA and Que reduced mRNA abundance and concentration of tumor necrosis factor-α (TNF-α), interleukin (IL)-6 and IL-8 (P < 0.001), and down-regulated gene expression of toll-like receptors 4 (TLR4) and its downstream signals (P < 0.001) after ETEC infection. PCA and Que down-regulated protein abundance of total receptor interacting protein kinase 1 (t-RIP1), phosphorylated-RIP1 (p-RIP1), p-RIP1/t-RIP1, t-RIP3, p-RIP3, mixed lineage kinase domain-like protein (MLKL), p-MLKL, dynamin- related protein 1 (DRP1), phosphoglycerate mutase 5 (PGAM5) and high mobility group box 1 (HMGB1) (P < 0.05) after ETEC infection. Moreover, PCA and Que reduced protein abundance of nod-like receptor protein 3 (NLRP3), nod-like receptors family CARD domain-containing protein 4 (NLRC4), apoptosis-associated speck-like protein containing a CARD (ASC), gasdermin D (GSDMD) and caspase-1 (P < 0.05) after ETEC infection.ConclusionsIn general, our data suggest that PCA and Que are capable of attenuating ETEC-caused intestinal inflammation and damage via inhibiting necroptosis and pyroptosis signaling pathways.

TRAF6 regulates the abundance of RIPK1 and inhibits the RIPK1/RIPK3/MLKL necroptosis signaling pathway and affects the progression of colorectal cancer

Colorectal cancer cannot be completely cured at present, and it is still an important clinical medical problem. TRAF6 is highly expressed in many malignant tumors. However, the role of TRAF6 in colorectal cancer is still controversial, mainly because the specific regulatory mechanism of colorectal cancer is still unclear, and the death mode of colorectal cancer cells has not been elucidated. The recent study found that TRAF6 inhibits necroptosis in colorectal cancer cells via the RIPK1/RIPK3/MLKL signaling pathway. The RIPK1 inhibitor Necrostain-1 inhibits colorectal cancer cell necroptosis via the RIPK1/RIPK3/MLKL signaling pathway. TRAF6 directly interacts with RIPK1 through the polyubiquitination of Lys48-linked RIPK1 and reduces the levels of RIPK1 protein in colorectal cancer cells, leading to necroptosis, thus promoting the proliferation of colorectal cancer cells. The recent study demonstrated that TRAF6 promotes colorectal cell progression by inhibiting the RIPK1/RIPK3/MLKL necroptosis signaling pathway, which may provide a new therapeutic target for colorectal cancer.

Necroptosis signaling pathways and its pharmacological implications in chronic inflammatory and infectious diseases - a minireview.

Necroptosis signaling pathways and its pharmacological implications in chronic inflammatory and infectious diseases - a minireview.

Mitochondrial dysfunction promotes the necroptosis of Purkinje cells in the cerebellum of acrylamide-exposed rats.

Acrylamide (ACR) is a common neurotoxicant that can induce central-peripheral neuropathy in human beings. ACR from occupational setting and foods poses a potential threat to people's health. Purkinje cells are the only efferent source of cerebellum, and their output is responsible for coordinating motor activity. Recent studies have reported that Purkinje cell injury is one of the earliest neurotoxicity at any dose rate of ACR. However, the mechanism underlying ACR-mediated damage to Purkinje cells remains unclear. This research aimed to investigate whether necroptosis is involved in ACR-induced Purkinje cell death and its regulatory mechanism. In this study, rats were treated with ACR (40mg/kg/every other day) for 6 weeks to establish an animal model of ACR neuropathy. Furthermore, an intervention experiment was achieved by rapamycin (RAPA), which is commonly used to activate mitophagy and maintain mitochondrial homeostasis. The results demonstrated ACR exposure caused necroptosis of Purkinje cells, mitochondrial dysfunction, and inflammatory response. By contrast, RAPA alleviated mitochondrial dysfunction and inhibited activation of necroptosis signaling pathway following ACR. In conclusion, our findings suggest that mitochondrial dysfunction and activation of necroptotic signaling are associated with the loss of Purkinje cells in ACR poisoning, which can be a potential therapeutic target for ACR neurotoxicity.

MiR-216b-5p promotes late apoptosis/necroptosis in trastuzumab-resistant SK-BR-3 cells.

Breast cancer is the most common cancer in women. The human epidermal growth factor receptor 2 (HER2) overexpressing subtype is related to poor prognosis with an aggressive phenotype and is reported as one of the most commonly seen subtypes. Trastuzumab is prevalently used as a treatment method for HER2+ breast cancer however, resistance to the drug frequently occurs following the treatment. MicroRNAs (miRNAs) are 19-23 nucleotide long small RNAs, which regulate gene expression at post-transcriptional level and studies show that there are differentially expressed miRNAs between drug sensitive and resistant groups, indicating that they might have some key roles in drug effectiveness. In this study, the aim is to find out the role of miR-216b-5p in trastuzumab resistance. SK-BR-3 cells developed resistance to trastuzumab after continuous treatment with increasing concentrations of the drug for 6 months. To investigate the effect of miR-216b-5p on cancer cell behavior in resistance state, proliferation, motility, and invasion capacities of these resistant cells were analyzed by xCELLigence real-time cell analyzer. To further understand the molecular mechanisms underlying the regulation of resistant SK-BR-3 cells by miR-216b-5p, microarray analysis was performed. Apoptosis analysis was also performed since the pathway enrichment analysis pointed out cell death related pathways. The proliferation, motility, and invasion capacities of the miR-216b-5p transfected resistant cells were diminished compared to sensitive cells. We identified the necroptosis signaling pathway as the result of microarray and pathway enrichment analyses. STAT1, IRF9, and PKR were validated as the significant elements of the pathway, which are also the putative targets of miR-216b-5p. Our apoptosis analysis showed that a significant amount of trastuzumab resistant SK-BR-3 cells entered to late apoptosis/necrosis stage upon miR-216b-5p overexpression, it could be concluded that reexpression of miR-216b-5p sensitizes trastuzumab resistance through necroptosis in breast cancer.

Construction and validation model of necroptosis-related gene signature associates with immunity for osteosarcoma patients

Osteosarcoma is the most common malignant tumor in children and adolescents and its diagnosis and treatment still need to be improved. Necroptosis has been associated with many malignancies, but its significance in diagnosing and treating osteosarcoma remains unclear. The objective is to establish a predictive model of necroptosis-related genes (NRGs) in osteosarcoma for evaluating the tumor microenvironment and new targets for immunotherapy. In this study, we download the osteosarcoma data from the TARGET and GEO websites and the average muscle tissue data from GTEx. NRGs were screened by Cox regression analysis. We constructed a prediction model through nonnegative matrix factorization (NMF) clustering and the least absolute shrinkage and selection operator (LASSO) algorithm and verified it with a validation cohort. Kaplan–Meier survival time, ROC curve, tumor invasion microenvironment and CIBERSORT were assessed. In addition, we establish nomograms for clinical indicators and verify them by calibration evaluation. The underlying mechanism was explored through the functional enrichment analysis. Eight NRGs were screened for predictive model modeling. NRGs prediction model through NMF clustering and LASSO algorithm was established. The survival, ROC and tumor microenvironment scores showed significant statistical differences among subgroups (P < 0.05). The validation model further verifies it. By nomogram and calibration, we found that metastasis and risk score were independent risk factors for the poor prognosis of osteosarcoma. GO and KEGG analyses demonstrate that the genes of osteosarcoma cluster in inflammatory, apoptotic and necroptosis signaling pathways. The significant role of the correlation between necroptosis and immunity in promoting osteosarcoma may provide a novel insight into detecting molecular mechanisms and targeted therapy.

Network Pharmacology and Molecular Docking Reveal the Mechanism of Tanshinone IIA against Pulmonary Hypertension

Background: Pulmonary hypertension (PH) is a complex disease caused by a wide range of underlying conditions, Tanshinone IIA (Tan IIA) has been widely used in PH patients. The study aimed to explore the possible molecular mechanism of Tan IIA against PH by network pharmacology and molecular docking. Methods: Tan IIA and PH-related targets were retrieved from public databases. Gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis, and protein–protein interaction (PPI) network were used to investigate the protein targets and mechanism. The binding activity of core targets and Tan IIA were verified by molecular docking. Results: A total of 26 overlapping target proteins between Tan IIA and PH were screened. PPI network identified HSP90AA1, PTPN11, ATM, CA2, TERT, PRKDC, and APEX1 as key pharmacological targets. The results of GO function enrichment analysis included regulation of smooth muscle cell proliferation and migration, regulation of mitotic cell cycle, and regulation of G1/S transition of mitotic cell cycle. KEGG pathway analysis showed that nitrogen metabolism, NF-kappa B signaling pathway, cell cycle, necroptosis, apoptosis, and JAK-STAT signaling pathway were associated with Tan IIA in PH. The molecular docking results showed that Tan IIA can closely bind three core targets (HSP90AA1, PTPN11, and CA2). Conclusions: The present work initially clarified the effective therapeutic targets, biological processes, and signaling pathways of Tan IIA treatment of PH, which lay a foundation for further research on the pharmacological effects of Tan IIA.

Bioinformatics analysis of potential pathogenesis and risk genes of immunoinflammation-promoted renal injury in severe COVID-19.

Renal injury secondary to COVID-19 is an important factor for the poor prognosis of COVID-19 patients. The pathogenesis of renal injury caused by aberrant immune inflammatory of COVID-19 remains unclear. In this study, a total of 166 samples from 4 peripheral blood transcriptomic datasets of COVID-19 patients were integrated. By using the weighted gene co-expression network (WGCNA) algorithm, we identified key genes for mild, moderate, and severe COVID-19. Subsequently, taking these genes as input genes, we performed Short Time-series Expression Miner (STEM) analysis in a time consecutive ischemia-reperfusion injury (IRI) -kidney dataset to identify genes associated with renal injury in COVID-19. The results showed that only in severe COVID-19 there exist a small group of genes associated with the progression of renal injury. Gene enrichment analysis revealed that these genes are involved in extensive immune inflammation and cell death-related pathways. A further protein-protein interaction (PPI) network analysis screened 15 PPI-hub genes: ALOX5, CD38, GSF3R, LGR, RPR1, HCK, ITGAX, LYN, MAPK3, NCF4, SELP, SPI1, WAS, TLR2 and TLR4. Single-cell sequencing analysis indicated that PPI-hub genes were mainly distributed in neutrophils, macrophages, and dendritic cells. Intercellular ligand-receptor analysis characterized the activated ligand-receptors between these immune cells and parenchyma cells in depth. And KEGG enrichment analysis revealed that viral protein interaction with cytokine and cytokine receptor, necroptosis, and Toll-like receptor signaling pathway may be potentially essential for immune cell infiltration leading to COVID-19 renal injury. Finally, we validated the expression pattern of PPI-hub genes in an independent data set by random forest. In addition, we found that the high expression of these genes was correlated with a low glomerular filtration rate. Including them as risk genes in lasso regression, we constructed a Nomogram model for predicting severe COVID-19. In conclusion, our study explores the pathogenesis of renal injury promoted by immunoinflammatory in severe COVID-19 and extends the clinical utility of its key genes.

The regulation of necroptosis by ubiquitylation.

Necroptosis is a programmed necrosis that is mediated by receptor-interacting protein kinases RIPK1, RIPK3 and the mixed lineage kinase domain-like protein, MLKL. Necroptosis must be strictly regulated to maintain normal tissue homeostasis, and dysregulation of necroptosis leads to the development of various inflammatory, infectious, and degenerative diseases. Ubiquitylation is a widespread post-translational modification that is essential for balancing numerous physiological processes. Over the past decade, considerable progress has been made in the understanding of the role of ubiquitylation in regulating necroptosis. Here, we will discuss the regulatory functions of ubiquitylation in necroptosis signaling pathway. An enhanced understanding of the ubiquitylation enzymes and regulatory proteins in necroptotic signaling pathway will be exploited for the development of new therapeutic strategies for necroptosis-related diseases.

Effect and mechanism of Dahuang Zhechong Pills against testicular aging in rats by inhibiting necroptosis signaling pathway

To explore the effect and mechanism of Dahuang Zhechong Pills(DHZCP), a classical prescription, in improving testicular aging(TA) in vivo, the authors randomly divided 24 male rats into four groups: the normal, model, DHZCP and vitamin E(VE) groups. The TA rat model was established by continuous gavage of D-galactose(D-gal). During the experiment, the rats in the DHZCP and VE groups were given DHZCP suspension and VE suspension, respectively by gavage, while those in the normal and model groups were gavaged saline separately every day. After the co-administration of D-gal and various drugs for 60 days, all rats were sacrificed, and their blood and testis were collected. Further, various indexes related to TA and necroptosis of testicular cells in the model rats were examined and investigated, which included the aging phenotype, total testicular weight, testicular index, histopathological features of testis, number of spermatogenic cells, sex hormone level, expression characteristics of reactive oxygen species(ROS) in testis, expression levels and characteristics of cyclins in testis, and protein expression levels of the key molecules in receptor-interacting serine/threonine-protein kinase 1(RIPK1)/receptor-interacting serine/threonine-protein kinase 3(RIPK3)/mixed lineage kinase domain like pseudokinase(MLKL) signaling pathway in each group. The results showed that, for the TA model rats, both DHZCP and VE improved their aging phenotype, total testicular weight, testicular index, pathological features of testis, number of spermatogenic cells, serum testosterone and follicle stimulating hormone levels, expression characteristics of ROS and protein expression levels and characteristics of P21 and P53 in testis. In addition, DHZCP and VE improved the protein expression levels of the key molecules in RIPK1/RIPK3/MLKL signaling pathway in testis of the model rats. Specifically, DHZCP was better than VE in the improvement of RIPK3. In conclusion, in this study, the authors found that DHZCP, similar to VE, ameliorated D-gal-induced TA in model rats in vivo, and its mechanism was related to reducing necroptosis of testicular cells by inhibiting the activation of RIPK1/RIPK3/MLKL signaling pathway. This study provided preliminary pharmacological evidence for the development and application of classical prescriptions in the field of men's health.

Chronic high-fat diet consumption exacerbates pyroptosis- and necroptosis-mediated HMGB1 signaling in the brain after ischemia and reperfusion injury.

Obesity is categorized as a common comorbidity found in people who experience an ischemic stroke. However, the mechanisms to explain this correlation have still not been elucidated fully. Pyroptosis and necroptosis are novel forms of programmed cell death that occur upon intracellular danger signals. The major feature of pyroptosis and necroptosis is damage to the lipid membrane, which consequently results in lytic cell death and allows the release of high mobility group box protein 1 (HMGB1) into the extracellular space. We aimed to investigate the influences of high-fat diet (HFD) consumption on cerebral ischemia and reperfusion (I/R) injury and hypothesized that HFD consumption exacerbated the activation of pyroptosis, necroptosis, and HMGB1 signaling pathways. All rats received normal diet (ND) or HFD for 16weeks. Subsequently, both groups were divided into either a sham- or an I/R-operated group. Twenty-four hours after the surgery, all rats were evaluated for neurological deficits and then sacrificed. After I/R injury, there were more severe functional deficits and larger brain infarcts in the HFD compared with the ND group. The histological observation revealed an increase in tissue abnormalities in the HFD group, consistent with the massive reduction of intact neurons along the peri-infarct region. Furthermore, cerebral I/R injury dramatically activated the pyroptotic, necroptotic, and HMGB1 signaling pathways in HFD-fed rats compared with ND-fed rats. These findings suggest that chronic HFD consumption worsens ischemic brain pathology and leads to poor post-stroke outcomes by exacerbating pyroptotic and necroptotic cell death.

Effects of Lysophosphatidylcholine on Jejuna Morphology and Its Potential Mechanism.

Lysophosphatidylcholine (LPC) plays a vital role in promoting jejuna morphology in broilers. However, the potential mechanism behind LPC improving the chicken jejuna morphology is unclear. Therefore, the present study was designed to reveal the important genes associated with LPC regulation in birds' jejuna. Thus, GSE94622, the gene expression microarray, was obtained from Gene Expression Omnibus (GEO). GSE94622 consists of 15 broiler jejuna samples from two LPC-treated (LPC500 and LPC1000) and the control groups. Totally 98 to 217 DEGs were identified by comparing LPC500 vs. control, LPC1000 vs. control, and LPC1000 vs. LPC500. Gene ontology (GO) analysis suggested that those DEGs were mainly involved in the one-carbon metabolic process, carbon dioxide transport, endodermal cell differentiation, the positive regulation of dipeptide transmembrane transport, cellular pH reduction, and synaptic transmission. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis indicated the DEGs were enriched in NOD-like receptor (NLR), RIG-I-like receptor (RILR), Toll-like receptor (TLR), and necroptosis signaling pathway. Moreover, many genes, such as RSAD2, OASL, EPSTI1, CMPK2, IFIH1, IFIT5, USP18, MX1, and STAT1 might be involved in promoting the jejuna morphology of broilers. In conclusion, this study enhances our understanding of LPC regulation in jejuna morphology.

Gene Expression Profile Analysis of Human Epidermal Keratinocytes Expressing Human Papillomavirus Type 8 E7.

Background: Human papillomavirus type 8 (HPV8) has been implicated in the progress of non-melanoma skin cancers and their precursor lesions. The HPV8 E7 oncoprotein plays a key role in the tumorigenesis of HPV-associated cutaneous tumors. However, the exact role of HPV8 E7 in human epidermal carcinogenesis has not been fully elucidated. Methods: To investigate the potential carcinogenic effects of HPV8 E7 on epithelial cells, we used RNA-sequencing technology to analyze the gene expression profile of HPV8 E7-overexpressed normal human epidermal keratinocytes (NHEKs). Results: RNA-sequencing revealed 831 differentially expressed genes (DEGs) between HPV8 E7-expressing NHEKs and control cells, among which, 631 genes were significantly upregulated, and 200 were downregulated. Gene ontology annotation enrichment analysis showed that HPV8 E7 mainly affected the expression of genes associated with protein heterodimerization activity, DNA binding, nucleosomes, and nucleosome assembly. Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis revealed that overexpression of HPV8 E7 affected the expression of gene clusters associated with viral carcinogenesis and transcriptional misregulation in cancer and necroptosis signaling pathways that reportedly play crucial roles in HPV infection promotion and cancer progression. We also found the DEGs, such as HKDC1 and TNFAIP3, were associated with epigenetic modifications, immune regulation, and metabolic pathways. Conclusion: Our results demonstrate that the pro-carcinogenic effect of HPV8 expression in epithelial cells may be attributed to the regulatory effect of oncogene E7 on gene expression associated with epigenetic modifications and immune and metabolic status-associated gene expression. Although our data are based on an in vitro experiment, it provides the theoretical evidence that the development of squamous cell carcinoma can be caused by HPV.

Fas/CD95 Signaling Pathway in Damage-Associated Molecular Pattern (DAMP)-Sensing Receptors.

Study of the initial steps of the CD95-mediated signaling pathways is a field of intense research and a long list of actors has been described in the literature. Nonetheless, the dynamism of protein-protein interactions (PPIs) occurring in the presence or absence of its natural ligand, CD95L, and the cellular distribution where these PPIs take place render it difficult to predict what will be the cellular outcome associated with the receptor engagement. Accordingly, CD95 stimulation can trigger apoptosis, necroptosis, pyroptosis, or pro-inflammatory signaling pathways such as nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and phosphatidylinositol-3-kinase (PI3K). Recent data suggest that CD95 can also activate pattern recognition receptors (PRRs) known to sense damage-associated molecular patterns (DAMPs) such as DNA debris and dead cells. This activation might contribute to the pro-inflammatory role of CD95 and favor cancer development or severity of chronic inflammatory and auto-immune disorders. Herein, we discuss some of the molecular links that might connect the CD95 signaling to DAMP sensors.

Nrf2 protects against cerebral ischemia-reperfusion injury by suppressing programmed necrosis and inflammatory signaling pathways.

BackgroundThe NOD-like receptor family pyrin domain-containing 3 (NLRP3) -mediated neuroinflammation is linked to neuronal necroptosis in cerebral ischemia-reperfusion (I/R) injury, especially in cerebral ischemic penumbra. This study was designed to investigate the regulation of nuclear factor E2-related factor-2 (Nrf2) on NLRP3 inflammasome in necroptosis signal pathway induced by I/R injury.MethodsWe investigated the mechanisms of Nrf2-negative regulation in necroptosis signaling pathway by using middle cerebral artery occlusion (MCAO) with Q-VD-OPH injected intraperitoneally. The protein level of the NLRP3 inflammasome was detected by western blot with Nrf2 knockdown and overexpression. NLRP3 inflammasome activation was Reactive oxygen species (ROS) dependent, and the protein level was regulated when N-acetylcysteine (NAC) and adenosine triphosphate (ATP) were selected as tools for regulating ROS.ResultsWe demonstrated the negative regulation of Nrf2 on NLRP3 inflammasome activation in Q-VD-OPH-induced necroptosis in cerebral artery I/R injury through Lentivirus-mediated RNA Interferenc, which mediated knockdown and overexpression of Nrf2. NLRP3 inflammasome activation was sensitive to both ATP-mediated ROS level increases and NAC-mediated ROS inhibition, suggesting that ROS is associated with the activation of NLRP3 inflammasome in necroptosis. In addition, Nrf2-induced NAD(P)H quinone dehydrogenase 1 (NQO1) was involved in the inhibition of NLRP3 inflammasome activation. These results suggest that Nrf2 regulates NQO1 to attenuate ROS, which negatively regulates NLRP3 inflammasome.ConclusionsNrf2/NQO1 was an inhibitor of ROS-induced NLRP3 inflammasome activation in Q-VD-OPH-induced necroptosis following cerebral I/R injury. Therefore, NLRP3 inflammasome could be a potential therapeutic target for cerebral ischemia.