Necroptosis Of Cells Research Articles

Fecal microbiota transplantation alleviates neuronal Apoptosis, necroptosis and M1 polarization of microglia after ischemic stroke

ObjectiveThis study aims to delve into the mechanisms underlying the improvement of neurological function in rats with ischemic stroke through fecal microbiota transplantation.Methods: A total of fifty male Sprague-Dawley rats were categorized into three groups: sham surgery, model, and fecal transplantation. We assessed behavioral and pathological alterations in the rats using modified neurological function scoring and TTC staining. Additionally, Western blot and immunofluorescence techniques were employed to examine the expression levels of RIP1, RIP3, MLKL, p-MLKL, Bcl-2, Bax, and cleaved caspase-3 in neurons of ischemic brain tissue, while iNOS and Arg1 were analyzed to evaluate microglial polarization.Results: The fecal transplantation group exhibited a decline in neurological function score compared to the model group, accompanied by a reduction in infarct volume (P < 0.05). Relative to the sham surgery group, the model group displayed a significant increase in the expression levels of necroptosis-related proteins RIP1, RIP3, p-MLKL, apoptotic proteins Bax and cleaved caspase-3, and the M1 microglial cell marker iNOS in ischemic brain tissue, while Bcl-2 expression was notably decreased (P < 0.05). Conversely, compared to the model group, the fecal transplantation group demonstrated decreased expression levels of RIP1, RIP3, p-MLKL, Bax, cleaved caspase-3, and iNOS, along with increased expression of Bcl-2.Conclusion: Fecal microbiota transplantation presents a promising avenue for enhancing neurological function in rats with ischemic stroke by inhibiting neuronal apoptosis, necroptosis, and M1 polarization of microglial cells.

Prenatal exposure to di-n-butyl phthalate promotes RIPK1-regulated necroptosis of uroepithelial cells and induces hypospadias through the epithelial-mesenchymal transition process in newborn male rats

Maternal exposure to di-n-butyl phthalate (DBP) has been linked to the induction of hypospadias; however, the underlying mechanism remains unclear. Necroptosis is reported to be implicated in developmental malformations. This study aimed to investigate the underlying mechanism of necroptosis in the development of hypospadias. DBP was dissolved in corn oil, and pregnant rats were administered a precisely measured dose of DBP (750 mg/kg/day) via gastric intubation from gestation day 14–18. Control rats received only corn oil. The day of birth was considered postnatal day (PND) 1. Male hypospadias rats were identified on PND 7. Genital tubercle tissues were collected and stored at −80°C for subsequent PCR analysis, cryopreserved in liquid nitrogen for western blot, or fixed in formalin for immunohistochemistry (IHC) staining. IHC staining and western blot analysis revealed increased expression of RIPK1 and necroptosis markers in genital tubercle (GT) tissue compared to the control group. Additionally, higher levels of EMT and impaired androgen receptor expression were observed in GT tissue. Exposure to increased DBP concentrations in rat primary uroepithelial cells (PUCs) led to elevated ROS production. Necroptosis markers and EMT expression levels were upregulated in PUCs following DBP incubation. Notably, treatment with DBP combined with necrostatin-1, a necroptosis inhibitor, reduced the expression of EMT markers and ROS production compared to DBP treatment alone. In vitro studies further revealed that DBP-induced necroptosis promoted the degradation of E-cadherin through the ubiquitin-proteasome pathway in PUCs. Our findings suggest that maternal exposure to DBP promotes necroptosis in uroepithelial cells by elevating ROS level and EMT status. Thus, necroptosis may play an essential role in the development of hypospadias.

Panorama of artery endothelial cell dysfunction in pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a fatal lung disease characterized by progressive pulmonary vascular remodeling. The initial cause of pulmonary vascular remodeling is the dysfunction of pulmonary arterial endothelial cells (PAECs), manifested by changes in the categorization of cell subtypes, endothelial programmed cell death, such as apoptosis, necroptosis, pyroptosis, ferroptosis, et al., overproliferation, senescence, metabolic reprogramming, endothelial-to-mesenchymal transition, mechanosensitivity, and regulation ability of peripheral cells. Therefore, it is essential to explore the mechanism of endothelial dysfunction in the context of PAH. This review aims to provide a comprehensive understanding of the molecular mechanisms underlying endothelial dysfunction in PAH. We highlight the developmental process of PAECs and changes in PAH and summarise the latest classification of endothelial dysfunction. Our review could offer valuable insights into potential novel EC-specific targets for preventing and treating PAH.

264.9: GSK3β deficiency ameliorates hepatic ischemia-reperfusion injury by regulating necroptosis of kupffer cells.

264.9: GSK3β deficiency ameliorates hepatic ischemia-reperfusion injury by regulating necroptosis of kupffer cells.

Activation of α7 Nicotinic Acetylcholine Receptors Inhibits Hepatic Necroptosis and Ameliorates Acute Liver Injury in Mice.

Acute liver injury is a disease characterized by severe liver dysfunction, caused by significant infiltration of immune cells and extensive cell death with a high mortality. Previous studies demonstrated that the α7 nicotinic acetylcholine receptor (α7nAChR) played a crucial role in various liver diseases. The hypothesis of this study was that activating α7nAChR could alleviate acute liver injury and investigate its possible mechanisms. Acute liver injury was induced by intraperitoneal injection of lipopolysaccharide (LPS)/D-galactosamine (D-Gal) in wild type, α7nAChR knockout (α7nAChR-/-) and stimulator of interferon gene (STING) mutation (Stinggt/gt) mice in the presence or absence of a pharmacologic selective α7nAChR agonist (PNU-282987). The effects of α7nAChR on hepatic injury, inflammatory response, mitochondrial damage, necroptosis, and infiltration of immune cells during acute liver injury were assessed. The expression of α7nAChR in liver tissue was increased in LPS/D-Gal-induced acute liver injury mice. Compared to the age-matched wild-type mice, α7nAChR deficiency decreased the survival rate, exacerbated the hepatic injury accompanied with enhanced inflammatory response and oxidative stress, and aggravated hepatic mitochondrial damage and necroptosis. Conversely, pharmacologic activation of α7nAChR by PNU-282987 displayed the opposite trends. Furthermore, PNU-282987 significantly reduced the proportion of infiltrating monocyte-derived macrophages (CD45+CD11bhiF4/80int), M1 macrophages (CD45+CD11b+F4/80+CD86hiCD163low), and Ly6Chi monocytes (CD45+CD11b+MHC [major histocompatibility complex] ⅡlowLy6Chi), but increased the resident Kupffer cells (CD45+CD11bintF4/80hiTIM4hi) in the damaged hepatic tissues caused by LPS/D-Gal. Interestingly, α7nAChR deficiency promoted the STING signaling pathway under LPS/D-Gal stimulation, while PNU-282987 treatment significantly prevented its activation. Finally, it was found that Sting mutation abolished the protective effects against hepatic injury by activating α7nAChR. The authors' study revealed that activating α7nAChR could protect against LPS/D-Gal-induced acute liver injury by inhibiting hepatic inflammation and necroptosis possibly via regulating immune cells infiltration and inhibiting STING signaling pathway.

Necroptosis in alveolar epithelial cells drives lung inflammation and injury caused by SARS-CoV-2 infection

COVID-19, caused by SARS-CoV-2 infection, results in irreversible or fatal lung injury. We assumed that necroptosis of virus-infected alveolar epithelial cells (AEC) could promote local inflammation and further lung injury in COVID-19. Since CD8+ lymphocytes induced AEC cell death via cytotoxic molecules such as FAS ligands, we examined the involvement of FAS-mediated cell death in COVID-19 patients and murine COVID-19 model. We identified the occurrence of necroptosis and subsequent release of HMGB1 in the admitted patients with COVID-19. In the mouse model of COVID-19, lung inflammation and injury were attenuated in Fas-deficient mice compared to Fas-intact mice. The infection enhanced Type I interferon-inducible genes in both groups, while inflammasome-associated genes were specifically upregulated in Fas-intact mice. The treatment with necroptosis inhibitor, Nec1s, improved survival rate, lung injury, and systemic inflammation. SARS-CoV-2 induced necroptosis causes cytokine induction and lung damage, and its inhibition could be a novel therapeutic strategy for COVID-19.

S100A8/A9-activated IFNγ+ NK cells trigger β-cell necroptosis in hepatitis B virus-associated liver cirrhosis

Background and aimsHepatitis B virus (HBV)-associated liver cirrhosis (LC), a common condition with high incidence and mortality rates, is often associated with diabetes mellitus (DM). However, the molecular mechanisms underlying impaired glucose regulation during HBV-associated LC remain unclear.MethodsData from 63 patients with LC and 62 patients with LC-associated DM were analysed. Co-culture of NK cells and islet β cell lines were used to study the glucose regulation mechanism. A mouse model of LC was used to verify the effect of S100A8/A9 on the glucose regulation.ResultsHigher levels of interferon (IFN)-γ derived from natural killer (NK) cells and lower levels of insulin emerged in the peripheral blood of patients with both LC and DM compared with those from patients with LC only. IFN-γ derived from NK cells facilitated β cell necroptosis and impaired insulin production. Furthermore, S100A8/A9 elevation in patients with both LC and DM was found to upregulate IFN-γ production in NK cells. Consistently, in the mouse model for LC, mice treated with carbon tetrachloride (CCL4) and S100A8/A9 exhibited increased blood glucose, impaired insulin production, increased IFN-γ, and increased β cells necroptosis compared with those treated with CCL4. Mechanistically, S100A8/A9 activated the p38 MAPK pathway to increase IFN-γ production in NK cells. These effects were diminished after blocking RAGE.ConclusionTogether, the data indicate that IFN-γ produced by NK cells induces β cell necroptosis via the S100A8/A9–RAGE–p38 MAPK axis in patients with LC and DM. Reduced levels of S100A8/A9, NK cells, and IFN-γ could be valuable for the treatment of LC with DM. Accumulation of S100A8/A9 in patients with LC may indicate the emergence of DM.

Siwu decoction suppress myeloid-derived suppressor cells through tumour cells necroptosis to inhibit hepatocellular carcinoma

BackgroundHuman hepatocellular carcinoma (HCC) acquired resistance to anti-cancer agents due to the presence of immunosuppressive tumour microenvironment (TME) established by the interaction between tumour cells and immune populations. New treatment targeting the interaction is urgently needed and clinically beneficial to patients with HCC. This study aims to explore the anti-tumour effect of a Traditional Chinese Medicine formula Siwu Decoction (SWD) and its potential mechanism. Materials and methodsThe chemical profile of SWD was determined by high-performance liquid chromatography coupled with mass spectrometry. In vitro and in vivo effects of SWD in regressing HCC were assessed. The role of myeloid-derived suppressor cells (MDSCs) in mediating SWD-induced HCC inhibition was determined by adoptive transfer assay. The regulation of SWD-induced interaction between HCC cells and MDSCs was also confirmed both in vitro and in vivo. ResultsSWD dose-dependent inhibited the HCC growth and lung metastasis in an orthotopic growth tumour in mice, without significant toxicity and adverse side effect. SWD induced necroptosis in HCC cells, but did not directly inhibit in vitro culture of MDSCs, instead, SWD-treated HCC cell culture supernatant suppressed MDSCs by inducing its cell apoptosis. The necroptotic response of HCC cells can also suppress the MDSCs population in the TME without reducing circulating MDSCs infiltration into the tumours. Adoptive transfer of MDSCs recovered tumour growth and lung metastasis of HCC in SWD-treated mice. In HCC cells, SWD induced a necroptotic response, and blockade of necroptotic response in HCC cells recovered the MDSCs population in vitro and in vivo, and restored tumour growth and lung metastasis in SWD-treated mice. A combination of SWD improves the anti-HCC efficacy of sorafenib without inducing adverse side effects. Albiflorin, the effective compound of SWD, its anti-HCC manner has been verified to be consistent with that of SWD. ConclusionOur study observed for the first time that SWD can suppress HCC by regulating MDSCs through necroptosis of tumour cells in the TME. The main effective compound of SWD, albiflorin can be a potential adjuvant therapy in the clinical management of human HCC.

Interleukin-18 binding protein regulates mast cell activation and mast cell induced osteoclastogenesis of rheumatoid arthritis.

Mast cell activation induces pathological responses, including increased osteoclastogenesis in rheumatoid arthritis (RA). Interleukin (IL)-18 binding protein (IL-18BP) has anti-inflammatory effects. In this study, we evaluated the effect of IL-18BP on mast cell activation and mast cell induced osteoclastogenesis. Mast cells were activated by IL-33 (100 ng/mL) and cultured with IL-18BP (10, 50, and 100 ng/mL). The proliferation, apoptosis, and necroptosis of mast cells were measured using flow cytometry. Enzyme-linked immunosorbent assay (ELISA) was used to measure the levels of mast cell enzymes, matrix metalloproteinase (MMP), soluble RANKL (sRANKL), and pro-inflammatory cytokines in the culture media. Monocytes from patients with RA patients (n=5) were cultured with activated mast cells with various concentrations of IL-18BP. TRAP+ multinucleated osteoclasts, bone resorption area, and osteoclast differentiation-related genes were measured. Proliferation of tryptase+chymase+c-kit+FcεR1+ mast cells was suppressed following incubation with IL-18BP (10, 50, and 100 ng/mL). RNA expression levels of tryptase and chymase were reduced by 100 ng/mL IL-18BP. Additionally, the levels of MMP-3/9, IL-17A, IL-6, TNF-α, and sRANKL were significantly inhibited by 100 ng/mL IL-18BP. Annexin V+ and annexin V-PI+ mast cells were reduced following incubation with 100 ng/mL IL-18BP. The addition of IL-33 significantly stimulated mast cell and increased TRAP+ multinucleated cells and bone resorption area, and these effects were suppressed by IL-18BP. The osteoclast-related genes (TRAP, ATP6v0d2, RANK, and cathepsin K) expression were suppressed by IL-18BP. IL-18BP suppressed mast cell activation and mast cell induced osteoclastogenesis. This suggests a potential anti-arthritic role for IL-18BP in patients with RA.

Exosomes originating from neural stem cells undergoing necroptosis participate in cellular communication by inducing TSC2 upregulation of recipient cells following spinal cord injury.

We previously demonstrated that inhibiting neural stem cells necroptosis enhances functional recovery after spinal cord injury. While exosomes are recognized as playing a pivotal role in neural stem cells exocrine function, their precise function in spinal cord injury remains unclear. To investigate the role of exosomes generated following neural stem cells necroptosis after spinal cord injury, we conducted single-cell RNA sequencing and validated that neural stem cells originate from ependymal cells and undergo necroptosis in response to spinal cord injury. Subsequently, we established an in vitro necroptosis model using neural stem cells isolated from embryonic mice aged 16-17 days and extracted exosomes. The results showed that necroptosis did not significantly impact the fundamental characteristics or number of exosomes. Transcriptome sequencing of exosomes in necroptosis group identified 108 differentially expressed messenger RNAs, 104 long non-coding RNAs, 720 circular RNAs, and 14 microRNAs compared with the control group. Construction of a competing endogenous RNA network identified the following hub genes: tuberous sclerosis 2 (Tsc2), solute carrier family 16 member 3 (Slc16a3), and forkhead box protein P1 (Foxpl). Notably, a significant elevation in TSC2 expression was observed in spinal cord tissues following spinal cord injury. TSC2-positive cells were localized around SRY-box transcription factor 2-positive cells within the injury zone. Furthermore, in vitro analysis revealed increased TSC2 expression in exosomal receptor cells compared with other cells. Further assessment of cellular communication following spinal cord injury showed that Tsc2 was involved in ependymal cellular communication at 1 and 3 days post-injury through the epidermal growth factor and midkine signaling pathways. In addition, Slc16a3 participated in cellular communication in ependymal cells at 7 days post-injury via the vascular endothelial growth factor and macrophage migration inhibitory factor signaling pathways. Collectively, these findings confirm that exosomes derived from neural stem cells undergoing necroptosis play an important role in cellular communication after spinal cord injury and induce TSC2 upregulation in recipient cells.

NIR-responsive CN-Pt-GEM hydrogel induces necroptosis and immunotherapeutic responses prevent postoperative recurrence and wound infection in lung carcinoma

BackgroundCancer recurrence following surgical resection is a major cause of treatment failure. Finding effective methods to prevent postoperative recurrence and wound infection is an important component of successful surgery. With the development of new nanotechnology, more treatment options have been provided for postoperative adjuvant therapy. This study presents an innovative hydrogel system that stimulates tumoricidal immunity after surgical resection of non-small cell lung cancer (NSCLC) and prevents cancer relapse.ResultsThe hydrogel system is based on the excellent photothermal conversion performance of single-atom platinum (CN-Pt) along with the delivery and release of the chemotherapy drug, gemcitabine (GEM). The system is coated onto the wound surface after tumor removal with subsequent near-infrared (NIR) photothermal therapy, which efficiently induces necroptosis of residual cancer cells, amplifies the levels of damage-associated molecular patterns (DAMPs), and increases the number of M1 macrophages. The significantly higher levels of phagocytic macrophages enhance tumor immunogenicity and sensitize cancer cells to CD8 + T-cell immunity to control postoperative recurrence, which has been verified using an animal model of postoperative lung cancer recurrence. The CN-Pt-GEM-hydrogel with NIR can also inhibit postoperative wound infection.ConclusionsThese findings introduce an alternative strategy for supplementing antitumor immunity in patients undergoing resection of NSCLC tumors. The CN-Pt-GEM-hydrogel with the NIR system also exhibits good biosafety and may be adaptable for clinical application in relation to tumor resection surgery, wound tissue filling, infection prevention, and recurrence prevention.

Identification of colon adenocarcinoma necroptosis subtypes and tumor antigens for the development of mRNA vaccines

BackgroundColon adenocarcinoma (COAD) is a serious public health issue due to high incidence and mortality rate. This study aimed to identify possible tumor antigens and necroptosis subtypes of COAD for the development of mRNA vaccines and the selection of appropriate patients for precision therapy. MethodsGene expression profiles and clinical information for COAD were obtained from The Cancer Genome Atlas and Gene Expression Omnibus, respectively. We comprehensively studied the alterations in necroptosis-related genes (NRGs) using cBioPortal, and screened the hub NRGs associated with the prognosis of patients with COAD using Gene Expression Profiling Interactive Analysis 2. Consensuses clustering analysis was performed to identify necroptosis subtypes. Weighted gene co-expression network analysis (WGCNA) was used to identify the co-expression modules of the NRGs. The necroptosis landscape of COAD was assessed using graph learning-based dimensionality reduction. Finally, a drug sensitivity analysis of the two necroptosis subtypes was performed. FindingsTwo tumor antigens, BLC-2-associated X protein (BAX) and interleukin 1 beta (IL1B) were identified based on their associations with prognosis of patients and antigen presenting cell infiltration. Two necroptosis subtypes (N1 and N2) were distinguished in patients with COAD, and they were characterized by their differential survival status and molecular expression levels of immune checkpoint proteins and immunogenetic cell death modulators. Furthermore, the necroptosis landscape of COAD indicated that individual patients had obvious heterogeneity. Co-expression modules were identified using WGCNA, and the hub NRGs were found to be involved in various immune processes. Drug sensitivity analysis indicated that there were significant differences in drug sensitivity between the N1 and N2 subtypes. Cell experiments suggested that both overexpression of BAX and IL1B promoted necroptosis of COAD cells and enhanced the cytotoxicity of CD8+ T cells. InterpretationBAX and IL1B are potential antigens for the development of anti-COAD mRNA vaccines, specifically for patients with the N2 subtype. Consequently, this study will guide the development of more effective immunotherapeutic approaches and the identification of appropriate patients.

Inhibition of β2-adrenergic receptor regulates necroptosis in prostate cancer cell

As the malignant tumor with the highest incidence in male, prostate cancer poses a significant threat to the reproductive health of elderly men. Our previous studies have shown that promoting necroptosis of cancer cells can effectively inhibit cancer cell proliferation. This study includes lentivirus-mediated knockdown of β2AR which resulted in stable transfectants that exhibited an increased ability to form clones compared to that of the negative control group. In the protein and mRNA levels, necroptosis associated RIP and mixed lineage kinase domain-like (MLKL) were significantly higher in the treatment group than they were in the control group. Furthermore, cells treated with propranolol exhibited necrotic morphology as observed by transmission electron microscopy. The combination of β2AR suppression and necroptosis inhibitors resulted in a more potent suppression of cell proliferation compared to that observed in the control and negative control groups. Additionally, it elevated in the necrosis rate as determined by flow cytometry. Immunofluorescence staining revealed enhanced RIP and MLKL expression in the sh-β2AR group compared to levels in the negative control group. Co-immunoprecipitation experiments detected an interaction between β2AR and RIP. MLKL and RIPK3 levels were significantly higher in xenograft tumor sections from the sh-β2AR group compared to levels in the sh-NC group. To conclude, our research indicates the proliferation of PC-3 and DU-145 cprostate cancer cells can be suppressed by inhibiting β2AR, and this occurs through the RIP/MLKL-mediated pathway of necroptosis.

Necroptosis contributes to the intestinal toxicity of deoxynivalenol and is mediated by methyltransferase SETDB1

Deoxynivalenol (DON) is a secondary metabolite produced by fungi, which causes serious health issues worldwide due to its widespread presence in human and animal diets. Necroptosis is a newly proposed cell death mode and has been proposed as a potential mechanism of intestinal disease. This study aimed to investigate the role of necroptosis in intestinal damage caused by DON exposure. Piglets were fed diets with or without 4 mg/kg DON for 3 weeks or given a gavage of 2 mg/kg BW DON or sterile saline to investigate the effects of chronic or acute DON exposure on the gut, respectively. IPEC-1 cells were challenged with different concentrations of DON to investigate the effect of DON exposure on the intestinal epithelial cells (IECs) in vitro. Subsequently, the inhibitors of necroptosis were used to treat cells or piglets prior to DON challenge. Chronic and acute DON exposure both caused morphological damage, reduction of disaccharidase activity, decrease of tight junction protein expression, inflammation of the small intestine, and necroptosis of intestinal epithelial cells in piglets. Necroptosis was also detected when IPEC-1 cell damage was induced by DON in vitro. The suppression of necroptosis in IPEC-1 cells by inhibitors (necrostatin-1 (Nec-1), GSK’872, or GW806742X) alleviated cell death, the decrease of tight junction protein expression, oxidative stress, and the inflammatory response induced by DON. Furthermore, pre-treatment with Nec-1 in piglets was also observed to protect the intestine against DON-induced enterotoxicity. Additionally, the expression of histone methyltransferase SETDB1 was abnormally downregulated upon chronic and acute DON exposure in piglets, and necroptosis was activated in IPEC-1 cells due to knockout of SETDB1. Collectively, these results demonstrate that necroptosis of IECs is a mechanism of DON-induced enterotoxicity and SETDB1 mediates necroptosis upon DON exposure in IECs, suggesting the potential for targeted inhibition of necroptosis to alleviate mycotoxin-induced enterotoxicity and intestinal disease.

Abstract 2143: Lyso-globotriaosylsphingosine Induces Endothelial Dysfunction Via Autophagy-dependent Regulation Of Necroptosis

Fabry disease is a lysosomal storage disorder characterized by the lysosomal accumulations of glycosphingolipids in a variety of cytotypes, which include endothelial cells. The disease is inherited and originates from an error in glycosphingolipid catabolism caused by insufficient α-galactosidase A activity, which causes uncontrolled progressive storage of intracellular globotriaosylceramide (Gb3) in vasculature and extracellular accumulation of lyso-Gb3 (a deacetylated soluble form of Gb3). Necrosis can lead to inflammation, which exacerbates necrosis and creates a positive feedback loop that triggers necroinflammation. However, the role played by necroptosis, a form of programed necrotic cell death, in the cell-to-cell inflammatory reaction between epithelial and endothelial cells is unclear. Thus, the present study was undertaken to determine whether lyso-Gb3 induces necroptosis and whether necroptosis inhibition protects endothelial dysfunction against lyso-Gb3 inflamed retinal pigment epithelial cells. We found lyso-Gb3 induced necroptosis of a retinal pigment epithelial cell line (ARPE-19) in an autophagy-dependent manner and that conditioned media (CM) from ARPE-19 cells treated with lyso-Gb3 induced the necroptosis, inflammation, and senescence of human umbilical vein endothelial cells. In addition, a pharmacological study showed CM from lyso-Gb3 treated ARPE-19 cells induced endothelial necroptosis, inflammation, and senescence were significantly inhibited by an autophagy inhibitor (3-MA) and by two necroptosis inhibitors (necrostatin and GSK-872), respectively. These results demonstrate lyso-Gb3 induces necroptosis via autophagy and suggest that lyso-Gb3 inflamed retinal pigment epithelial cells trigger endothelial dysfunction via autophagy-dependent necroptosis pathway. This study suggests the involvement of a novel autophagy-dependent necroptosis pathway in the regulation of endothelial dysfunction in Fabry disease.

Neuregulin-1 reduces necroptosis and protects mice from death caused by respiratory viral infection

Abstract Respiratory syncytial virus (RSV) and influenza type A virus (IAV) cause significant morbidity and mortality even with available vaccines. Pre-existing atopy provides protection against death in mice infected with Sendai virus (SeV), a rodent virus related to RSV. We found neuregulin-1 (NRG1) expressed at high levels in atopic mice, and when given exogenously (500 ng/day i.n for five days) to non-atopic mice provides significant protection against mortality from lethal doses of both SeV (2x106 pfu) and IAV (3x103 pfu PR8-mouse adapted). Further, using well-differentiated human airway epithelial cells, NRG-1 was found to improve epithelial barrier function following RSV infection. RSV has been reported to cause necroptosis, which can induce inflammation and alter epithelial membrane permeability. We hypothesized the survival advantage of NRG1 involves inhibition of necroptosis. Treating cells from the murine airway epithelial cell line LET-1 with NRG1 before inoculation with SeV significantly inhibited viral induced necroptosis as measured by a real-time non-lytic apoptosis/necroptosis assay. Furthermore, NRG1 reduced expression of genes promoting necroptosis (RIPK3 and MLKL) in well-differentiated human bronchial epithelial cells 72h post RSV infection. Together, these data suggest NRG1 modulates viral induced cell death through inhibition of necroptosis of epithelial cells and may explain the reduced airway leak and increased survival seen in our model.

Methionine-choline deficient diet deteriorates DSS-induced murine colitis through disturbance of gut microbes and infiltration of macrophages.

Ulcerative colitis (UC) is associated with changed dietary habits and mainly linked with the gut microbiota dysbiosis, necroptosis of epithelial cells, and mucosal ulcerations. Liver dysfunction and abnormal level of liver metabolism indices were identified in UC patients, suggesting a close interaction between gut and liver disorders. Methionine-choline deficient diet (MCD) has been shown to induce persistent alterations of gut microbiota and metabolome during hepatitis. In this study we further explored the disease phenotypes in UC patients and investigated whether MCD functioned as a trigger for UC susceptibility. After assessing 88 serum specimens from UC patients, we found significant liver dysfunction and dyslipidemia including abnormal ALT, AST, TG, TC, LDL-c and HDL-c. Liver dysfunction and dyslipidemia were confirmed in DSS-induced colitis mice. We fed mice with MCD for 14 days to cause mild liver damage, and then treated with DSS for 7 days. We found that MCD intake significantly exacerbated the pathogenesis of mucosal inflammation in DSS-induced acute, progressive, and chronic colitis, referring to promotion of mucosal ulcers, colon shortening, diarrhea, inflammatory immune cell infiltration, cytokines release, and abnormal activation of inflammatory macrophages in colon and liver specimens. Intraperitoneal injection of clodronate liposomes to globally delete macrophages dramatically compromised the pathogenesis of MCD-triggering colitis. In addition, MCD intake markedly changed the production pattern of short-chain fatty acids (SCFAs) in murine stools, colons, and livers. We demonstrated that MCD-induced colitis pathogenesis largely depended on the gut microbes and the disease phenotypes could be transmissible through fecal microbiota transplantation (FMT). In conclusion, this study supports the concept that intake of MCD predisposes to experimental colitis and enhances its pathogenesis via modulating gut microbes and macrophages in mice.

Exogenous Hydrogen Sulfide Prevents Necroptosis by Inhibiting p38MAPK Pathway Activation in JEG-3 Trophoblast Cells: A Role in Preeclampsia

Objectives: Necroptosis, a form of programmed cell death, can occur in the placenta of patients with preeclampsia (PE). Hydrogen sulfide (H2S) can inhibit necroptosis of human umbilical vein endothelial cells under the high glucose-induced injury. Whether H2S can protect trophoblasts against necroptosis underlying PE has not been elucidated. This study aimed to explore the protective role of H2S in trophoblast cells against necroptosis underlying PE. Design: This is an in vitro experimental study. Participants: A total of 10 pregnant women with severe PE and 10 matched control normotensive pregnant women were included. The placenta tissues were extracted from participators. The human JEG-3 trophoblasts were commercially available. Methods: The expression and localization of necrotic proteins were assayed in human placenta samples, and the effect of necrotic cell death on the proliferation and apoptosis of human JEG-3 trophoblasts was evaluated. The component expressions of inflammatory cytokine and p38MAPK signaling pathway were measured in samples pretreated with or without NaHS (H2S donor) and SB203580 (p38 inhibitor). Results: RIPA1, RIPA3, and p-p38 levels were significantly higher in PE placental tissue, whereas cystathionine β-synthase expression was decreased. In JEG-3 trophoblasts, necroptosis increased apoptotic cell numbers, suppressed cell proliferation, increased inflammatory cytokine expression, and increased p38MAPK activation, which can be prevented by NaHS. Limitations: In the present study, we did not provide sufficient evidence that necroptosis was a part of the pathogenesis of PE. Conclusions: We proposed the putative role of necroptosis in early-onset PE, reflected by the blockage of caspase-8/3 and increased expression of RIPA1 and RIPA3 in PE placenta tissues. Furthermore, we demonstrated that exogenous H2S protected cytotrophoblasts against ceramide-induced necroptosis via the p38MAPK pathway.

Membrane-anchoring clickable Iridium(III) nanosonosensitizer in situ evokes PANoptosis for augmented tumor sono-immunotherapy

Developing activatable “off-on” sonosensitizers with superior sonodynamic activity and immunogenic cell death (ICD) induction ability is urgently needed for precise and boosted tumor sono-immunotherapy. Herein, a membrane-anchoring clickable Iridium(III) nanosonosensitizer is well-designed to elicit tumor-specific PANoptosis for enhanced sonodynamic therapy (SDT) and amplified immune activation. A click-activatable tetrazine-functionalized Iridium(III) sonosensitizer Tz-Ir with dual type I/II reactive oxygen species (ROS) generation ability is developed, and further encapsulated into crosslinked human serum albumin (HSA) to form acid-responsive nanosonosensitizer HSA@Tz-Ir. After tumor-targeting accumulation and acidic tumor microenvironment (TME)-triggered release, Tz-Ir can synchronously realize efficient click-activation and precise membrane-localization via specific bioorthogonal metabolic glycoengineering technology. Upon US irradiation, in situ activated Tz-Ir can generate abundant ROS to destroy tumor cell membrane for a high-efficiency SDT. Moreover, for the first time, the maximized membrane damage is certified to evoke highly immunogenic PANoptosis (pyroptosis, apoptosis and necroptosis) of tumor cells, resulting in remarkably amplified tumor immunogenicity. The PANoptosis-boosted ICD effect can elicit robust systemic adaptive and innate antitumor immunity to effectively inhibit the growths of primary/distant tumors and lung metastasis. This tumor-specific membrane-targeting SDT modality based on bioorthogonal click activation presents an innovative strategy for precise and augmented tumor sono-immunotherapy.

CircHIPK3 targets DRP1 to mediate hydrogen peroxide-induced necroptosis of vascular smooth muscle cells and atherosclerotic vulnerable plaque formation

IntroductionNecroptosis triggered by H2O2 is hypothesized to be a critical factor in the rupture of atherosclerotic plaques, which may precipitate acute cardiovascular events. Nevertheless, the specific regulatory molecules of this development remain unclear. We aims to elucidate a mechanism from the perspective of circular RNA. ObjectivesThere are few studies on circRNA in VSMCs necroptosis. The objective of our research is to shed light on the intricate roles that circHIPK3 plays in the process of necroptosis in VSMCs and the development of atherosclerotic plaques that are prone to rupture. Our study elucidates the specific molecular mechanisms by which circHIPK3 regulates necroptosis and atherosclerotic vulnerable plaque formation through targeted proteins. Identifying this mechanism at the cellular level offers a molecular framework for understanding plaque progression and stability regulation, as well as a potential biomarker for the prognosis of susceptible atherosclerotic plaques. MethodsWe collected clinical vascular tissue for HE staining and Masson staining to determine the presence and stability of plaques. Then, NCBI database was used to screen out circRNA with elevated expression level in plaque tissue, and the up-regulated circRNA, circHIPK3, was verified by qRT-PCR and FISH. Further, we synthesized circHIPK3′s small interference sequence and overexpressed plasmid in vitro, and verified its regulation effect on necroptosis of VSMCs under physiological and pathological conditions by WB, qRT-PCR and PI staining. Through RNA pull down, mass spectrometry and RNA immunoprecipitation, DRP1 was identified as circHIPK3 binding protein and was positively regulated by circHIPK3. Meanwhile, on the basis of silencing of DRP1, the regulation of circHIPK3 on necroptosis is verified to be mediated by DRP1. Finally, we validated the regulation of circHIPK3 on vulnerable plaque formation in ApoE-/- mice. ResultsWe investigated that circHIPK3 was highly expressed in vulnerable plaques, and the increase in expression level promoted H2O2 induced necroptosis of VSMCs. CircHIPK3 targeted the protein DRP1, leading to an elevation in mitochondrial division rate, resulting in increased reactive oxygen species and impaired mitochondrial function, ultimately leading to necroptosis of VSMCs and vulnerable plaque formation. ConclusionCircHIPK3 interact with DRP1 involve in H2O2 induced Mitochondrial damage and necroptosis of VSMCs, and Silencing circHIPK3 in vivo can reduce atherosclerotic vulnerable plaque formation. Our research findings may have applications in providing diagnostic biomarkers for vulnerable plaques.