Recombinant CC16 inhibits NLRP3/caspase-1-induced pyroptosis through p38 MAPK and ERK signaling pathways in the brain of a neonatal rat model with sepsis

ACVR1 drives neuropathic pain by regulating NLRP3-Induced neuronal pyroptosis through the p38 and Smad1/5/8 pathways

BACKGROUND

Neuropathic pain is characterized by sustained pain hypersensitivity caused by nerve injury. The molecular mechanisms underlying this condition remain poorly understood. This study aims to elucidate the role of ACVR1 and its downstream pathways in mediating neuropathic pain through neuronal pyroptosis and neuroinflammation.

METHODS

A spared nerve injury (SNI) model was established both in male and female mouse to induce neuropathic pain. Behavioral tests, Western blot, PCR, and immunofluorescence were used to assess the expression of ACVR1, p-Smad1/5/8, p-p38, and pyroptosis-related proteins (NLRP3, Caspase-1, and GSDMD-N). ACVR1, p38, and Smad1/5/8 were pharmacologically inhibited to evaluate their roles in neuropathic pain and pyroptosis.

RESULTS

Behavioral analysis confirmed successful SNI model establishment, marked by reduced paw withdrawal thresholds (PWT). Protein and mRNA expression analysis revealed significant upregulation of ACVR1, p-Smad1/5/8, and p-p38 in the spinal cord, particularly in neurons. Furthermore, SNI enhanced pyroptosis-related protein expression, including NLRP3, Caspase-1, GSDMD-N, IL-1β and IL-18. Inhibition of ACVR1 alleviated mechanical allodynia, reduced neuronal pyroptosis, and decreased serum IL-1β and IL-18 levels. Similarly, p38 inhibition mitigated NLRP3-induced pyroptosis without altering ACVR1 expression. In contrast, Smad1/5/8 inhibition by DMH-1 effectively reduced pyroptosis and inflammation via NLRP3 but had no effect on p38 phosphorylation. Combined p38 and Smad1/5/8 pathway inhibition synergistically decreased pyroptosis-related protein expression, highlighting their interactive roles in ACVR1-mediated neuropathic pain.

CONCLUSION

These findings suggest that ACVR1 exacerbates neuropathic pain by activating neuronal pyroptosis and neuroinflammation via the p38 and Smad1/5/8 pathways. Targeting ACVR1 and its downstream signaling pathways may offer novel therapeutic strategies for neuropathic pain.

rhCC16 Suppresses Cellular Senescence and Ameliorates COPD-Like Symptoms by Activating the AMPK/Sirt1-PGC-1-α-TFAM Pathway to Promote Mitochondrial Function

Chronic obstructive pulmonary disease (COPD) is a widespread lung disease marked by alveolar wall damage, leading to inflammation and fibrosis. Key risk factors include age, smoking, sex, and education, with smoking being the most crucial. These factors are globally consistent and linked with aging. Club cell secretory protein 16 (CC16), primarily secreted by non-ciliated bronchial epithelial cells, is crucial for pulmonary health, offering anti-inflammatory and antioxidant benefits. CC16 levels are notably reduced in COPD, suggesting its enhancement as a potential treatment. In this study, cellular senescence of BEAS-2B cells was stimulated using cigarette smoke extract (CSE) and the function of recombinant human CC16 protein (rhCC16) in cellular senescence was assessed by detecting the levels of β-galactosidase, p16, p21, ROS and the underlined mechanism was revealed by measuring mitochondrial biogenesis and metabolism. Additionally, COPD mice were prepared, and rhCC16's role on the cellular senescence of lung tissues was examined. Our findings showed that rhCC16 ameliorated cellular senescence in BEAS-2B cells and lung tissues of COPD mice accompanied by lower levels of β-galactosidase, p16, p21 and ROS. Mechanically, rhCC16 mitigated senescence via triggering PGC-1α expression through the AMPK/SIRT1 pathway and fostering mitochondrial biogenesis and metabolism to reduce the levels of ROS. Furthermore, the results also indicated that rhCC16 exerted its effect via both integrin α4β1 and clathrin-mediated endocytosis. Collectively, rhCC16 suppresses cellular senescence and ameliorates COPD-like symptoms by activating the AMPK/Sirt1-PGC-1-α-TFAM pathway to foster mitochondrial function.

The role of programmed cell death in organ dysfunction induced by opportunistic pathogens

Sepsis is a life-threatening condition resulting from pathogen infection and characterized by organ dysfunction. Programmed cell death (PCD) during sepsis has been associated with the development of multiple organ dysfunction syndrome (MODS), impacting various physiological systems including respiratory, cardiovascular, renal, neurological, hematological, hepatic, and intestinal systems. It is well-established that pathogen infections lead to immune dysregulation, which subsequently contributes to MODS in sepsis. However, recent evidence suggests that sepsis-related opportunistic pathogens can directly induce organ failure by promoting PCD in parenchymal cells of each affected organ. This study provides an overview of PCD in damaged organ and the induction of PCD in host parenchymal cells by opportunistic pathogens, proposing innovative strategies for preventing organ failure in sepsis.

IL-8 promotes pyroptosis through ERK pathway and mediates glucocorticoid resistance in chronic rhinosinusitis with nasal polyps

OBJECTIVE

This study seeks to elucidate the role and molecular mechanisms of IL-8 in nasal epithelial cell pyroptosis and its impact on glucocorticoid (GC) resistance.

METHODS

We assessed the expression of pyroptosis-related biomarkers and IL-8 in tissues and human nasal epithelial cells (hNECs) from both control and nasal polyp patients using western blot. Their localization was determined through immunohistochemistry and immunofluorescence. Cell death and cytotoxicity assay, electron microscopy, ELISA, and immunofluorescence were utilized to investigate IL-8-induced pyroptosis and GC resistance in hNECs, alongside the examination of the involved signaling pathways via western blot and immunofluorescence. In a murine model, hematoxylin-eosin staining and immunohistochemistry clarified relationship between pyroptosis and GC resistance.

RESULTS

IL-8 and pyroptotic biomarker expression were significantly higher in nasal polyp-derived tissues and hNECs compared to controls. IL-8 showed a positive correlation and co-localized with the pyroptotic biomarkers. IL-8 triggered pyroptosis in hNECs by activating the ERK signaling pathway, leading to increased IL-1β and IL-18 secretion. Moreover, IL-8-induced pyroptosis was found to contribute to GC resistance by affecting phosphorylation of GC receptor Ser211. Inhibition of pyroptotic proteins mitigated IL-8-induced GC resistance both in vitro and in vivo.

CONCLUSION

Elevated IL-8 facilitates pyroptosis via the ERK signaling pathway and plays a significant role in GC resistance in nasal polyps.

Macrophage-derived exosomal miR-2137 regulates pyroptosis in LPS-induced acute lung injury

BACKGROUND

Alveolar macrophages (AMs) play a predominant role in acute lung injury (ALI). However, the role of macrophage-derived exosomal miRNAs in lipopolysaccharide (LPS)-induced ALI has not been determined.

METHODS

We previously reported that exosomes in the bronchoalveolar lavage fluid (BALF) of mice with ALI were derived predominantly from macrophages. Exosomal small RNA sequencing was conducted to identify the miRNA profiles. Exosomes derived from LPS-induced macrophages (LPS-exos) were intravenously administered to C57BL/6J mice, after which lung injury and pyroptosis were assessed. LPS-exos were cultured with alveolar epithelial cells (AECs) to further validate the results of the animal studies.

RESULTS

LPS-exos promoted lung inflammation and pyroptosis in vivo and in vitro. MiR-2137 was significantly upregulated in both LPS-exos and in MLE-12 cells. LPS-exos reduced cell viability, promoted the expression of LDH and inflammatory cytokines, and exacerbated vacuolization in MLE-12 cells. The administration of miR-2137 mimics and LPS-treated exosomes further strengthened these effects and enhanced pyroptosis mediated by NLRP3, Caspase1, ASC, and GSDMD. MiR-2137 mediated the effects of LPS-exos by targeting Wnt9a in AECs. In addition, the miR-2137 inhibitor markedly decreased the severity of LPS-exo-induced histological lesions, inflammation and pyroptosis in the lung.

CONCLUSION

Exosomal miR-2137 derived from AMs contributes to LPS-induced ALI by inducing AEC pyroptosis through the targeting of Wnt9a to activate the Wnt signaling pathway. This study revealed that AMs and AECs interact in ALI, providing novel strategies for ALI treatment.

Exploring and Validating the Mechanism of Ulinastatin in the Treatment of Sepsis-Associated Encephalopathy Based on Transcriptome Sequencing

Purpose

Sepsis can induce sepsis-associated encephalopathy (SAE), with Ulinastatin (UTI) serving a critical anti-inflammatory role. This study aimed to identify the hub genes in an SAE mouse model following UTI intervention and investigate the underlying molecular mechanisms.

Materials and Methods

Through differential expression analysis to obtain differentially expressed genes (DEGs), ie, UTI vs CLP (DEGs1) and Con vs CLP (DEGs2). After taking the intersection of the genes with opposite differential trends in these two parts and immune-related genes (IRGs), DE-IRGs were obtained. Hub genes in the protein-protein interaction (PPI) network were then determined using six algorithms from the Cytohubba plugin in Cytoscape. Gene set enrichment analysis (GSEA) was employed to explore the functional relevance of these hub genes. Additionally, the immune microenvironment across the three groups was compared, and hub gene-related drugs were predicted using an online database. Finally, qRT-PCR was used to validate the expression of the hub genes in hippocampal tissue from CLP mice.

Results

RNA sequencing obtained 864 differentially expressed genes (DEGs) (CLP vs Con) and 279 DEGs (UTI vs CLP). Taking the intersection of DEGs with opposite expression trends yielded 165 DEGs. Six key genes (ICAM - 1, IRF7, IL - 1β, CCL2, IL - 6 and SOCS3) were screened by six algorithms. Immune infiltration analysis found that Treg cells were reversed after treatment with UTI in the diseased state. A total of 106 hub - gene - related drugs were predicted, among which BINDARIT - CCL2 and LIFITEGRAST - ICAM1 showed particularly high affinities. The qRT - PCR verification results were consistent with the sequencing results.

Conclusion

In conclusion, ICAM-1, IRF7, IL-1β, CCL2, IL-6, and SOCS3 were identified as potential therapeutic targets in SAE mice treated with UTI. This study offers theoretical support for UTI as a treatment option for SAE.

Interleukin-1β Signaling Contributes to Cell Cycle Arrest and Apoptotic Cell Death by Leptin via Modulation of AKT and p38MAPK in Hepatocytes

Leptin, an adipose tissue-derived hormone, has exhibited the potent hepatotoxic effects. However, the underlying molecular mechanisms are not fully understood. In this study, we have elucidated the mechanisms by which leptin exerts cytotoxic effects in hepatocytes, particularly focusing on the role of interleukin-1β (IL-1β) signaling. Leptin significantly induced maturation and secretion of IL-1β in cultured rat hepatocytes. Interestingly, inhibition of IL-1β signaling by pretreatment with an IL-1 receptor antagonist (IL-1Ra) or gene silencing of type I IL-1 receptor (IL-1R1) markedly abrogated leptin-induced cell cycle arrest. The critical role of IL-1β signaling in leptin-induced cell cycle arrest is mediated via upregulation of p16, which acts as an inhibitor of cyclin-dependent kinase. In addition, leptin-induced apoptotic cell death was relieved by inhibition of IL-1β signaling, as determined by annexin V/7-AAD binding assay. Mechanistically, IL-1β signaling contributes to apoptotic cell death and cell cycle arrest by suppressing AKT and activation of p38 mitogen-activated protein kinase (p38MAPK) signaling pathways. Involvement of IL-1β signaling in cytotoxic effect of leptin was further confirmed in vivo using hepatocyte specific IL-1R1 knock out (IL-1R1 KO) mice. Essentially similar results were obtained in vivo, where leptin administration caused the upregulation of apoptotic markers, dephosphorylation of AKT, and p38MAPK activation were observed in wild type mice liver without significant effects in the livers of IL-1R1 KO mice. Taken together, these results demonstrate that IL-1β signaling critically contributes to leptin-induced cell cycle arrest and apoptosis, at least in part, by modulating p38MAPK and AKT signaling pathways.

WIP1-mediated regulation of p38 MAPK signaling attenuates pyroptosis in sepsis-associated acute kidney injury

Wild-Type p53-Induced Phosphatase 1 (WIP1/PPM1D) is a serine/threonine phosphatase that plays a significant role in various physiological processes. However, the involvement of WIP1 in kidney remains unclear. Lipopolysaccharide (LPS) was administered to induce acute injury in mice and human kidney 2 (HK2) cells in the study. The WIP1 inhibitor, CCT007093, was administered both in vitro and in vivo to assess its effect on kidney. The single-cell sequencing (scRNA-seq) data revealed that Ppm1d mRNA reached peak on day 2 following unilateral ischemia-reperfusion injury (uni-IRI) in mice, especially in the proximal renal tubules during repair phase. Compared to the control group, WIP1 protein exhibited a significant increase in renal tubules of patients with acute tubular injury (ATI) and mice with LPS-induced acute kidney injury (AKI), as well as in LPS-injured HK2 cells. In vitro experiments showed that CCT007093 increased the protein levels of NLRP3, cleaved-Caspase1, GSDMD-N and IL-1β in HK2 cells and further reduced the viability of LPS-stimulated HK2 cells. In vivo experiments showed that inhibition of WIP1 activity with CCT007093 further increased cleaved-Caspase1, GSDMD-N protein levels in kidney tissue from mice with LPS-induced AKI. In addition, LPS induces phosphorylation of p38 MAPK, a key regulator of pyroptosis, which is further activated by CCT007093. In conclusion, inhibition of WIP1 activity acts as a positive regulator of renal tubular pyroptosis mainly through the mediation of phospho-p38 MAPK.

Picroside II suppresses chondrocyte pyroptosis through MAPK/NF-κB/NLRP3 signaling pathway alleviates osteoarthritis

BACKGROUND

Picroside II (P-II) is the main bioactive constituent of Picrorhiza Kurroa, a traditional Chinese herb of interest for its proven anti-inflammatory properties. Its beneficial effects have been noted across several physiological systems, including the nervous, circulatory, and digestive, capable of treating a wide range of diseases. Nevertheless, the potential of Picroside II to treat osteoarthritis (OA) and the mechanisms behind its efficacy remain largely unexplored.

AIM

This study aims to evaluate the efficacy of Picroside II in the treatment of osteoarthritis and its potential molecular mechanisms.

METHODS

In vitro, we induced cellular inflammation in chondrocytes with lipopolysaccharide (LPS) and subsequently treated with Picroside II to assess protective effect on chondrocyte. We employed the Cell Counting Kit-8 (CCK-8) assay to assess the impact of Picroside II on cell viability and select the optimal Picroside II concentration for subsequent experiments. We explored the effect of Picroside II on chondrocyte pyroptosis and its underlying molecular mechanisms by qRT-PCR, Western blot (WB) and immunofluorescence. In vivo, we established the destabilization of the medial meniscus surgery to create an OA mouse model. The therapeutic effects of Picroside II were then assessed through Micro-CT scanning, Hematoxylin-eosin (H&E) staining, Safranin O-Fast Green (S&F) staining, immunohistochemistry and immunofluorescence.

RESULTS

In in vitro studies, toluidine blue and CCK-8 results showed that a certain concentration of Picroside II had a restorative effect on the viability of chondrocytes inhibited by LPS. Picroside II notably suppressed the expression levels of caspase-1, IL-18, and IL-1β, which consequently led to the reduction of pyroptosis. Moreover, Picroside II was shown to decrease NLRP3 inflammasome activation, via the MAPK/NF-κB signaling pathway. In vivo studies have shown that Picroside II can effectively reduce subchondral bone destruction and osteophyte formation in the knee joint of mice after DMM surgery.

CONCLUSIONS

Our research suggests that Picroside II can inhibit chondrocyte pyroptosis and ameliorate osteoarthritis progression by modulating the MAPK/NF-κB signaling pathway.

HECTD3 promotes NLRP3 inflammasome and pyroptosis to exacerbate diabetes-related cognitive impairment by stabilising MALT1 to regulate JNK pathway

BACKGROUND

HECTD3 (HECT domain E3 ubiquitin protein ligase 3) exerts biological activities in neuroinflammation of distinct diseases, such as autoimmune encephalomyelitis and donations after heart death. However, the effect of HECTD3 on diabetes-associated cognitive decline (DACD) remains unclear.

METHODS

Wild-type or HECTD3-knockout rats were administered with streptozotocin to establish diabetic model. Pathological changes in the hippocampus were assessed by NISSL and haematoxylin and eosin staining. Morris water maze test was used to assess cognitive function. Neuronal survival and inflammation were investigated by immunofluorescence staining and ELISA assay. NLRP3 inflammasome and pyroptosis were assessed by western blot, immunofluorescence and flow cytometry assays.

RESULTS

HECTD3 was up-regulated in hippocampus of streptozotocin-induced diabetic rats and high glucose-induced PC12 cells. Knockout of HECTD3 increased the number of neurons and improved the learning and memory function. Moreover, knockout of HECTD3 promoted in vivo neuronal survival, and reduced levels of IL-1β, TNF-α, and IL-6 in the hippocampus. Silencing of HECTD3 increased cell viability, and reduced IL-1β, TNF-α, and IL-6 in high glucose-induced PC12 cells. Fluorescence intensities of NLRP3, GSDMD-N and caspase-1 were reduced in HECTD3-knockout diabetic rats, and knockdown of HECTD3 down-regulated protein expression of NLRP3, GSDMD-N, caspase-1, IL-1β, and IL-18 in high glucose-induced PC12 cells to suppress the pyroptosis. HECTD3 promoted the stability of mucosa-associated lymphoid tissue 1 (MALT1) through up-regulation of c-JUN and phospho (p)-JNK in high glucose-induced PC12 cells. Over-expression of MALT1 attenuated neuroprotective effects of HECTD3 silencing on high glucose-induced PC12 cells.

CONCLUSION

HECTD3 silencing exerted neuroprotective effect against DACD through MALT1-mediated JNK signalling.HighlightsHECTD3 was up-regulated in hippocampus of streptozotocin-induced diabetic rats and high glucose-induced PC12.Knockout of HECTD3 promoted in vivo neuronal survival, reduced inflammation and pyroptosis, and improved the learning and memory function in diabetic rats.Knockout of HECTD3 suppressed the activation of NLRP3 inflammasome in diabetic rats.Silencing of HECTD3 exerted neuroprotective effects through MALT1-mediated JNK signalling.

ELANE is a promising prognostic biomarker that mediates pyroptosis in gastric cancer

Background

Gastric cancer (GC) is a typical malignant tumor and the main cause of cancer-related deaths. Its pathogenesis involves multiple steps, including pyroptosis, although these steps are still uncertain. Pyroptosis, also known as gasdermin-mediated programmed necrosis, participates in various pathological processes in tumors, including GC. ELANE, which encodes neutrophil elastase, is closely associated with GC. Additionally, ELANE has been implicated in GC cell pyroptosis, but this has not been confirmed. Therefore, investigating the link between ELANE and pyroptosis in GC is warranted. This research uses bioinformatics and experiments to examine the relationship between ELANE, pyroptosis, and GC prognosis.

Methods

The GEO and TCGA databases, along with pyroptosis-related genes, were applied to identify pyroptosis-related differentially expressed genes (DEGs). ELANE was selected via primary screening. Using the median expression level of ELANE as the threshold, pyroptosis-related DEGs were divided into low- and high-ELANE groups. Based on the DEGs in these two groups, GO, KEGG and GSEA analyses were conducted to elucidate the mechanisms of ELANE in GC. Furthermore, we plotted ROC and Kaplan-Meier curves to analyze the clinical and pathological features of ELANE expression. The Nomograms tool was applied to calculate the predictive value of ELANE for the clinical outcomes of GC cases. Immunohistochemical analysis was performed to detect the level of ELANE in GC tissues and to validate whether ELANE was involved in pyroptosis in GC cells through cell experiments. Finally, the immune infiltration of ELANE was investigated, and interaction networks (proteins-ELANE, microRNA-ELANE, and small-molecule drug-ELANE) were constructed.

Results

We aimed to investigate the expression of the ELANE gene in GC and study the relationship among ELANE, pyroptosis, and the prognosis of patients with GC. Differential expression analysis of gene-expression datasets from TCGA-STAD and GSE49051 revealed that the expression of the ELANE gene was significantly up-regulated in GC. Using STRING network analysis, we identified multiple proteins involved in the occurrence and development of GC, including interactions between ELANE and GSDMC, a member of the gasdermin protein family. Survival analysis showed that ELANE expression levels significantly affected overall survival (OS), disease-free survival (DFS), and progression-free survival (PFS) in patients with GC. Additionally, ROC analysis demonstrated that ELANE was effective in distinguishing GC patients from normal controls (AUC = 0.812). Immunohistochemical analysis showed that ELANE was highly expressed in gastric cancer tissues and was closely related to age, tumor grade, and stage. The cell experiments further confirmed that the high expression of ELANE in gastric cancer cells was associated with pyroptosis. Comprehensive analysis indicated that ELANE could be used as a potential prognostic marker for GC and plays an important role in pyroptosis.

Conclusion

High ELANE expression is related to poor survival and prognosis of patients with GC. It participates in pyroptosis and immune infiltration in GC. Therefore, ELANE is a promising prognostic biomarker for pyroptosis in GC.

Americanin B inhibits pyroptosis in lipopolysaccharide-induced septic encephalopathy mice through targeting NLRP3 protein

BACKGROUND

Sepsis is considered as a severe illness due to its high mortality. Sepsis can cause septic encephalopathy, thus leading to brain injury, behavioral and cognitive dysfunction. Pyroptosis is a type of regulated cell death (RCD) and takes a crucial part in occurrence and development of sepsis. Americanin B (AMEB) is a lignan compounds, which is extracted from Vernicia fordii. In our previous study, AMEB could inhibit microglial activation in inflammatory cell model. However, the function of AMEB in septic encephalopathy mice is uncertain. It would be worthwhile to ascertain the role and mechanism of AMEB in sepsis.

PURPOSE

Current study designs to certify the relationship between pyroptosis and septic encephalopathy, and investigate whether AMEB can restrain NOD-like receptor pyrin domain-containing 3 (NLRP3) inflammasome activation and restrict pyroptosis by targeting NLRP3 in septic mice model.

STUDY DESIGN

C57BL/6 mice were utilized to perform sepsis model in vivo experiments. BV-2 cell lines were used for in vitro experiments.

METHODS

In vivo sepsis model was established by lipopolysaccharide (LPS) intraperitoneal injection in male C57BL/6 J mice and in vitro model was exposed by LPS plus ATP in BV-2 cells. The survival rate was monitored on the corresponding days. NLRP3, apoptosis associated Speck-like protein (ASC), caspase-1, GasderminD (GSDMD), interleukin-1β (IL-1β) and interleukin-18 (IL-18) level were detected by western blotting and immunofluorescence analysis. Molecular docking, cellular thermal shift assay (CETSA), drug affinity responsive target stability (DARTS) experiments, RNAi transfection and quantitative real-time PCR were applied to confirm the potential target of AMEB.

RESULTS

The results suggested that AMEB could rise survival percentage and lighten brain injury in LPS-induced sepsis mice. In addition, AMEB could inhibit pyroptosis and the activiation of NLRP3 inflammasome. The inhibiting function of AMEB on the activiation of NLRP3 inflammasome is weakened following si-NLRP3 transfection. Moreover, AMEB exerted anti-pyroptosis effect via targeting NLRP3 protein.

CONCLUSIONS

Our findings first indicate NLRP3 is an effective druggable target for septic encephalopathy related brain injury, and also provide a candidate-AMEB for the treatment of septic encephalopathy. These emerging findings on AMEB in models of sepsis suggest an innovative approach that may be beneficial in the prevention of septic encephalopathy.

Pyroptosis in sepsis induced organ dysfunction

As an uncontrolled inflammatory response to infection, sepsis and sepsis induced organ dysfunction are great threats to the lives of septic patients. Unfortunately, the pathogenesis of sepsis is complex and multifactorial, which still needs to be elucidated. Pyroptosis is a newly discovered atypical form of inflammatory programmed cell death, which depends on the Caspase-1 dependent classical pathway or the non-classical Caspase-11 (mouse) or Caspase-4/5 (human) dependent pathway. Many studies have shown that pyroptosis is related to sepsis. The Gasdermin proteins are the key molecules in the membrane pores formation in pyroptosis. After cut by inflammatory caspase, the Gasdermin N-terminal fragments with perforation activity are released to cause pyroptosis. Pyroptosis is closely related to the occurrence and development of sepsis induced organ dysfunction. In this review, we summarized the molecular mechanism of pyroptosis, the key role of pyroptosis in sepsis and sepsis induced organ dysfunction, with the aim to bring new diagnostic biomarkers and potential therapeutic targets to improve sepsis clinical treatments.

Effect of ethanol exposure on innate immune response in sepsis

Alcohol use disorder, reported by 1 in 8 critically ill patients, is a risk factor for death in sepsis patients. Sepsis, the leading cause of death, kills over 270,000 patients in the United States alone and remains without targeted therapy. Immune response in sepsis transitions from an early hyperinflammation to persistent inflammation and immunosuppression and multiple organ dysfunction during late sepsis. Innate immunity is the first line of defense against pathogen invasion. Ethanol exposure is known to impair innate and adaptive immune response and bacterial clearance in sepsis patients. Specifically, ethanol exposure is known to modulate every aspect of innate immune response with and without sepsis. Multiple molecular mechanisms are implicated in causing dysregulated immune response in ethanol exposure with sepsis, but targeted treatments have remained elusive. In this article, we outline the effects of ethanol exposure on various innate immune cell types in general and during sepsis.

MSC-derived exosomal miR-140-3p improves cognitive dysfunction in sepsis-associated encephalopathy by HMGB1 and S-lactoylglutathione metabolism

MiRNAs in mesenchymal stem cells (MSCs)-derived exosome (MSCs-exo) play an important role in the treatment of sepsis. We explored the mechanism through which MSCs-exo influences cognitive impairment in sepsis-associated encephalopathy (SAE). Here, we show that miR-140-3p targeted Hmgb1. MSCs-exo plus miR-140-3p mimic (Exo) and antibiotic imipenem/cilastatin (ABX) improve survival, weight, and cognitive impairment in cecal ligation and puncture (CLP) mice. Exo and ABX inhibit high mobility group box 1 (HMGB1), IBA-1, interleukin (IL)-1β, IL-6, iNOS, TNF-α, p65/p-p65, NLRP3, Caspase 1, and GSDMD-N levels. In addition, Exo upregulates S-lactoylglutathione levels in the hippocampus of CLP mice. Our data further demonstrates that Exo and S-lactoylglutathione increase GSH levels in LPS-induced HMC3 cells and decrease LD and GLO2 levels, inhibiting inflammatory responses and pyroptosis. These findings suggest that MSCs-exo-mediated delivery of miR-140-3p ameliorates cognitive impairment in mice with SAE by HMGB1 and S-lactoylglutathione metabolism, providing potential therapeutic targets for the clinical treatment of SAE.

Targeting novel regulated cell death：Ferroptosis, pyroptosis, and autophagy in sepsis-associated encephalopathy

Sepsis-associated encephalopathy (SAE), a common neurological complication of sepsis, is a heterogenous complex clinical syndrome caused by the dysfunctional response of a host to infection. This dysfunctional response leads to excess mortality and morbidity worldwide. Despite clinical relevance with high incidence, there is a lack of understanding for its both its acute/chronic pathogenesis and therapeutic management. A better understanding of the molecular mechanisms behind SAE may provide tools to better enhance therapeutic efficacy. Mounting evidence indicates that some types of non-apoptotic regulated cell death (RCD), such as ferroptosis, pyroptosis, and autophagy, contribute to SAE. Targeting these types of RCD may provide meaningful targets for future treatments against SAE. This review summarizes the core mechanism by which non-apoptotic RCD leads to the pathogenesis of SAE. We focus on the emerging types of therapeutic compounds that can inhibit RCD and delineate their beneficial pharmacological effects against SAE. Within this review we suggest that pharmacological inhibition of non-apoptotic RCD may serve as a potential therapeutic strategy against SAE.

ARC@DPBNPs suppress LPS-induced acute lung injury via inhibiting macrophage pyroptosis and M1 polarization by ERK pathway in mice

AIM OF THE STUDY

Exploring the protective effect of ARC@DPBNP on lipopolysaccharides (LPS)-induced ALI and its underlying mechanism.

MATERIALS AND METHODS

ALI model was established by intransally administrating LPS (4 mg/kg) into C57BL/6 mice. The suppression effects of ALI was first compared between ARC (intragastric administrated, with doses ranging from 10 to 80 mg/kg) and ARC@BPBNPs (intratracheally administrated, with doses ranging from 1 to 4 mg/kg). Changes in lung histology post intratracheal intervention of 3 mg/kg ARC@DPBNPs were detected. The expression of pyrotosis pathway-related proteins in lungs as well as in RAW264.7 cells was detected by western blotting. The ASC expression in lung macrophages was examined using immune-fluorescent staining. The polarization of RAW264.7 cells and lung macrophages were detected by flow cytometry. The network pharmacology was constructed by Cytoscape, and the molecular docking was perfomed by AutoDock Vina.

RESULTS

Docking predicted the high affinity of ARC to MAPK1 (ERK2). HE staining showed that ARC@DPBNPs attenuated LPS-induced ALI at a remarkably lower dose than ARC. The improved histopathological changes, lung W/D weight ratio, and decreased of inflammatory factor levels in lung collectively demonstrated the alleviation effects of ARC@DPBNPs. Compared with the LPS group, ARC@DPBNPs down-regulated the ERK pathway, resulted in a suppression of the macrophage pyroptosis and M1 polarization. This suppression effects could be removed by the ERK activator Ro 67-7476.

CONCLUSION

ARC@DPBNPs attenuated ALI by suppressing LPS-induced macrophage pyroptosis and polarization, probably through down-regulation of the ERK pathway.

Deciphering the molecular mechanism of NLRP3 in BPA-mediated toxicity: Implications for targeted therapies

Bisphenol-A (BPA), a pervasive industrial chemical used in polymer synthesis, is found in numerous consumer products including food packaging, medical devices, and resins. Detectable in a majority of the global population, BPA exposure occurs via ingestion, inhalation, and dermal routes. Extensive research has demonstrated the adverse health effects of BPA, particularly its disruption of immune and endocrine systems, along with genotoxic potential. This review focuses on the complex relationship between BPA exposure and the NOD-like receptor protein 3 (NLRP3) inflammasome, a multiprotein complex central to inflammatory disease processes. We examine how BPA induces oxidative stress through the generation of intracellular free radicals, subsequently activating NLRP3 signaling. The mechanistic details of this process are explored, including the involvement of signaling cascades such as PI3K/AKT, JAK/STAT, AMPK/mTOR, and ERK/MAPK, which are implicated in NLRP3 inflammasome activation. A key focus of this review is the wide-ranging organ toxicities associated with BPA exposure, including hepatic, renal, gastrointestinal, and cardiovascular dysfunction. We investigate the immunopathogenesis and molecular pathways driving these injuries, highlighting the interplay among BPA, oxidative stress, and the NLRP3 inflammasome. Finally, this review explores the emerging concept of targeting NLRP3 as a potential therapeutic strategy to mitigate the organ toxicities stemming from BPA exposure. This work integrates current knowledge, emphasizes complex molecular mechanisms, and promotes further research into NLRP3-targeted interventions.

IL-1β, the first piece to the puzzle of sepsis-related cognitive impairment?

Sepsis is a leading cause of death resulting from an uncontrolled inflammatory response to an infectious agent. Multiple organ injuries, including brain injuries, are common in sepsis. The underlying mechanism of sepsis-associated encephalopathy (SAE), which is associated with neuroinflammation, is not yet fully understood. Recent studies suggest that the release of interleukin-1β (IL-1β) following activation of microglial cells plays a crucial role in the development of long-lasting neuroinflammation after the initial sepsis episode. This review provides a comprehensive analysis of the recent literature on the molecular signaling pathways involved in microglial cell activation and interleukin-1β release. It also explores the physiological and pathophysiological role of IL-1β in cognitive function, with a particular focus on its contribution to long-lasting neuroinflammation after sepsis. The findings from this review may assist healthcare providers in developing novel interventions against SAE.

Hemerocallis citrina Baroni ameliorates chronic sleep deprivation-induced cognitive deficits and depressive-like behaviours in mice

Sleep deprivation (SD) is common during spaceflight. SD is known to cause cognitive deficits and depression, requiring treatment and prevention. Hemerocallis citrina Baroni (Liliaceae) is a perennial herb with antidepressant, antioxidant, antitumor, anti-inflammatory, and neuroprotective effects.The aim of our study was to investigate the effects of H. citrina extract (HCE) on SD-induced cognitive decline and depression-like behavior and possible neuroinflammation-related mechanisms. HCE (2 g/kg/day, i.g.) or vortioxetine (10 mg/kg/day, i.g.) were given to mice by oral gavage for a total of 28 days during the SD process. HCE treatment was found to ameliorate SD-induced impairment of short- and long-term spatial and nonspatial memory, measured using Y-maze, object recognition, and Morris water maze tests, as well as mitigating SD-induced depression-like behaviors, measured by tail suspension and forced swimming tests. HCE also reduced the levels of inflammatory cytokines (IL-1β, IL-18, and IL-6) in the serum and hippocampus. Furthermore, HCE suppressed SD-induced microglial activation in the prefrontal cortex (PFC) and the CA1 and dentate gyrus (DG) regions of the hippocampus. HCE also inhibited the expression of phosphorylated NF-κB and activation of the NLRP3 inflammasome. In summary, our findings indicated that HCE attenuated SD-induced cognitive impairment and depression-like behavior and that this effect may be mediated by the inhibition of inflammatory progression and microglial activation in the hippocampus, as well as the down-regulation of NF-κB and NLRP3 signaling. The findings of these studies showingTthese results indicate that HCE exerts neuroprotective effects and are consistent with the findings of previous studies, suggesting that HCE is beneficial for the prevention and treatment of cognitive decline and depression in SD.

Elucidating the role of Pyroptosis in papillary thyroid cancer: prognostic, immunological, and therapeutic perspectives

BACKGROUND

Pyroptosis, an inflammatory form of programmed cell death, has been implicated in the pathogenesis and progression of several cancers. However, the significance of pyroptosis-related genes (PRGs) in papillary thyroid cancer (PTC) remains unclear.

METHODS

Transcriptome and clinical data of PTC patients were obtained from The Cancer Genome Atlas. The expression patterns of PRGs were identified by consensus clustering. A prognostic model for predicting the thyroid cancer-free interval (TCFi) employed five machine learning methods. Enrichment and immune-related analyses were performed to elucidate the role of pyroptosis. The responses to radioactive iodine (RAI), immune checkpoint inhibitors (ICIs), molecular targeted therapy (MTT), and chemotherapy (CTx) were predicted based on pyroptosis-derived features. Additionally, the expression of prognostic PRGs was validated via six external datasets, 16 cell lines, and 20 pairs of clinical samples.

RESULTS

PTC patients were classified into three PyroClusters, C1 exhibited BRFA-like tumors with the highest invasiveness and the worst prognosis, C2 presented RAS-like tumors, and C3 was characterized by gene fusion. Nine PRGs (CXCL8, GJA1, H2BC8, IFI27, PRDM1, PYCARD, SEZ6L2, SIGLEC15, TRAF6) were filtered out to construct a PyroScore prognostic model. A derived nomogram demonstrated superior predictive performance than four clinical staging systems. A strong correlation between pyroptosis and tumor immune microenvironment (TIME) remodeling was observed in mechanistic analyses. Patients with a high PyroScore exhibited "hot" tumor immunophenotypes and had a poorer prognosis but could benefit more from ICIs and CTx (such as paclitaxel). Patients with a low PyroScore were more sensitive to RAI and MTT (such as pazopanib and sorafenib).

CONCLUSIONS

PyroScore model can effectively predict TCFi in patients with PTC. Dysregulated expression of PRGs is associated with the TIME modeling. Pyroptosis features have potential significance for developing novel therapeutic strategies for PTC patients.

IL-17A/p38 Signaling Pathway Induces Alveolar Epithelial Cell Pyroptosis and Hyperpermeability in Sepsis-Induced Acute Lung Injury by Activating NLRP3 Inflammasome

Sepsis is a syndrome with poor prognosis. Nucleotide-binding domain-like receptor family pyrin domain containing 3 (NLRP3) inflammasome and T helper 17 (Th17) cells are involved in the pathogenesis of inflammatory diseases. This study aims to explore their roles and underlying mechanisms in sepsis. The blood and bronchoalveolar lavage fluid are collected from sepsis patients and healthy donors. A sepsis mice model is established by cecal ligation puncture (CLP). The contents of cytokines are detected by ELISA. The amounts of Th17 cells, IL-17A, IL-1β, IL-18, and lipopolysaccharide is significantly elevated in sepsis patients. The increased differentiation of Th17 cells can promote lung cell pyroptosis and induce hyperpermeability via activating NLRP3 inflammasome and p38 pathway. The inhibitors targeting Th17 cells, NLRP3 inflammasome, and p38 pathway can significantly alleviate lung injury in sepsis mice. Th17 cells can secrete IL-17A to activate NLRP3 inflammasome via p38 signaling pathway, which contributes to the development of sepsis-induced acute lung injury.

Naringin inhibits P2X4 receptor expression on satellite glial cells in the neonatal rat dorsal root ganglion

Naringin inhibits inflammation and oxidative stress, the P2 purinoreceptor X4 receptor (P2X4R) is associated with glial cell activation and inflammation, the purpose of this study is to investigate the effects of naringin on P2X4 receptor expression on satellite glial cells (SGCs) and its possible mechanisms. ATP promoted the SGC activation and upregulated P2X4R expression; naringin inhibited SGC activation, decreased expression of P2X4R, P38 MAPK/ERK, and NF-κB, and reduced levels of Ca2+, TNF-α, and IL-1β in SGCs in an ATP-containing environment. These findings suggest that naringin attenuates the ATP-induced SGC activation and reduces P2X4R expression via the Ca2+-P38 MAPK/ERK-NF-κB pathway.

PIK3CG Regulates NLRP3/GSDMD-Mediated Pyroptosis in Septic Myocardial Injury

Cardiac insufficiency is a common complication of sepsis with high mortality. Inflammatory programmed cell death (pyroptosis) executed by NLRP3/gasdermin D (GSDMD) is intrinsically correlated with septic myocardial injury. However, it remains unclear whether PIK3CG, a classical target of septic myocardial injury, can affect pyroptosis by regulating NLRP3/GSDMD signaling. In this study, a series of experimental methods were used to observe the effect of PIK3CG on NLRP3/GSDMD-mediated pyroptosis in Cecal ligation and puncture (CLP)-injured BALB/c mice and lipopolysaccharide (LPS)-injured HL-1 cardiomyocytes. Transcriptome analysis of CLP-injured myocardium revealed a regulatory relationship between PIK3CG and NLRP3/GSDMD signaling, which was further verified in clinical myocardium samples from GEO database. Both in vitro and in vivo experiments showed that the protein and mRNA levels of PIK3CG, GSDMD, NLRP3, IL-1β, Caspase-1, and IL-18 were significantly increased. Importantly, PIK3CG siRNA was found to improve these changes, while PIK3CG overexpression worsened them. Notably, pyroptosis induced by CLP in the myocardium was reversed by the PIK3CG inhibitor (AS-604850). In conclusion, PIK3CG activates NLRP3 inflammasomes, thus promoting pyroptosis in septic myocardial injury.

HET0016 inhibits neuronal pyroptosis in the immature brain post-TBI via the p38 MAPK signaling pathway

Traumatic brain injury (TBI) is a serious health threat worldwide, especially for the younger demographic. Our previous study demonstrated that HET0016 (a specific inhibitor of 20-hydroxyeicosatetraenoic acid synthesis) can decrease the lesion volume in the immature brain post-TBI; however, its mechanism of action and its association with pyroptosis post-TBI are unclear. In this study, we established a controlled cortical impact (CCI) injury rat model (postnatal day 9-10) and observed that increased expression of indicators for pyroptosis, including NLR family pyrin domain containing 3 (NLRP3), caspase-1 and gasdermin D (GSDMD) proteins and interleukin (IL)-18/IL-1β mRNA during the acute phase of TBI, especially on post-injury day (PID) 1. Additionally, we found that caspase-1 was primarily expressed in the neurons and microglia. HET0016 (1 mg/kg/d, ip, 3 consecutive days since TBI) reduced the lesion volume; neuronal death; expression of NLRP3, caspase-1, and GSDMD; and expression of IL-18/IL-1β mRNA. Bioinformatics analysis suggested involvement of mitogen-activated protein kinase (MAPK) signaling pathway in the HET0016-mediated neuroprotective role against TBI in the immature brain. Western blot analysis revealed reduced expression of p-p38 MAPK and nuclear factor-kappa B (NF-κB) p65 in the neurons and microglia upon HET0016 treatment in TBI rats. In cultured primary cortical neurons subjected to oxygen-glucose deprivation/re-oxygenation (OGD) + (lipopolysaccharide) LPS, HET0016-induced the reduction of p-p38 MAPK, NLRP3, cleaved-caspase-1, GSDMD, IL-18, and IL-1β was reversed by co-treatment with p38 MAPK activator as well as NLRP3 agonist. Therefore, we conclude that pyroptosis is involved in neuronal death in the immature brains post-TBI and that HET0016 administration can alleviate neuronal pyroptosis possibly via inhibiting the phosphorylation of p38 MAPK.

Role of SIRT1 in sepsis-induced encephalopathy: Molecular targets for future therapies

Sepsis induces neuroinflammation, BBB disruption, cerebral hypoxia, neuronal mitochondrial dysfunction, and cell death causing sepsis-associated encephalopathy (SAE). These pathological consequences lead to short- and long-term neurobehavioural deficits. Till now there is no specific treatment that directly improves SAE and its associated behavioural impairments. In this review, we discuss the underlying mechanisms of sepsis-induced brain injury with a focus on the latest progress regarding neuroprotective effects of SIRT1 (silent mating type information regulation-2 homologue-1). SIRT1 is an NAD+ -dependent class III protein deacetylase. It is able to modulate multiple downstream signals (including NF-κB, HMGB, AMPK, PGC1α and FoxO), which are involved in the development of SAE by its deacetylation activity. There are multiple recent studies showing the neuroprotective effects of SIRT1 in neuroinflammation related diseases. The proposed neuroprotective action of SIRT1 is meant to bring a promising therapeutic strategy for managing SAE and ameliorating its related behavioural deficits.

Research progress on pyroptosis and its effect on the central nervous system

Pyroptosis is an inflammatory and lysis type of programmed cell death. In the canonical pyroptosis signaling pathway, the NLRP3 inflammasome activates inflammatory caspase-1, which then shears cut the executor protein GSDMD. The N domains of GSDMD move to heterogeneous membranes, form pores, and release inflammatory cytokines IL-1β and IL-18, causing cell membrane swelling and rupture. Pyroptosis is mainly regulated by the key proteins in the signaling pathway, including inflammasome, caspase-1, GSDMD, IL-1β, and IL-18, as well as their agonists and inhibitors. Appropriate pyroptosis can improve host defense mechanisms, while excessive pyroptosis would derive pathological effects on central nervous system, leding to neuroinflammatory response, blood-brain barrier damage, and cognitive disfunction.

SIRT3 alleviates sepsis-induced acute lung injury by inhibiting pyroptosis via regulating the deacetylation of FoxO3a

OBJECTIVE

This study mainly analyzes the mechanism of SIRT3 alleviating sepsis-induced acute lung injury (ALI) by regulating the deacetylation of FoxO3a and inhibiting pyroptosis.

METHODS

SIRT3-overexpressing and silenced BEAS-2B cells were used to evaluate the effect of SIRT3 on apoptosis in LPS-treated lung epithelial cells. FoxO3a-silenced BEAS-2B cells were also used to verify the mechanism by which SIRT3 inhibited oxidative stress and pyroptosis in vitro in ALI. 3-TYP was used to inhibit the deacetylation function of SIRT3 in vivo. Pyroptosis was assessed by detecting GSDMD-N and LDH efflux.

RESULTS

In CLP-induced ALI mice, GSDMD-N and LDH levels were elevated, pyroptosis was induced. Silencing of SIRT3 exacerbated oxidative stress, NLRP3 activation and pyroptosis, and inhibited the deacetylation of FoxO3a. Overexpression of SIRT3 attenuated pyroptosis, induced deacetylation and restored the expression of FoxO3a and MnSOD. Silencing FoxO3a aggravated pyroptosis. Overexpression of SIRT3 restored the reduced FoxO3a expression and suppressed pyroptosis. 3-TYP blocked the promotion of FoxO3a by SIRT3 and the inhibitory effect of SIRT3 on pyroptosis.

CONCLUSION

The reduction of SIRT3 in sepsis caused hyperacetylation of FoxO3a, which in turn exacerbates oxidative stress and induces pyroptosis of ALI. Increasing the level of SIRT3 promotes FoxO3a through deacetylation, thereby inhibiting pyroptosis and relieving ALI.

Toll-like receptor 4 promotes the inflammatory response in septic acute kidney injury by promoting p38 mitogen-activated protein kinase phosphorylation

Septic acute kidney injury (AKI) contributes to the mortality and morbidity of sepsis patients. Toll-like Receptor 4 (TLR4) has prominent roles in septic AKI. This study investigated the functions of TLR4 in septic AKI. A septic AKI mouse model was established by cecal ligation and puncture surgery. Mouse kidney function and kidney tissue lesion were examined using corresponding kits and H&E staining. The in vitro cell model of septic AKI was established by lipopolysaccharide induction. Cell viability, inflammatory factor (TNF-α, IL-6, IL-4, IL-1β, IL-18) levels, pyroptotic cell number changes, lactate dehydrogenase (LDH) activity, myeloperoxidase (MOP) concentration, and levels of pyroptosis-associated protein and MyD88, TRIF and p38 MAPK phosphorylation were determined by MTT, ELISA, FAM-FLICA Caspase-1 Detection kit, other corresponding kits, and Western blot. TLR4 was highly expressed in septic AKI mouse kidney tissues and human septic AKI cells. TLR4 knockdown alleviated kidney injury, increased cell viability, and reduced LDH activity and MPO concentration. TLR4 knockdown reduced cell pyroptosis by repressing p38 MAPK phosphorylation through MyD88/TRIF, suppressed pro-inflammatory factor (TNF-α, IL-6, IL-4, IL-1β, IL-18) levels, promoted anti-inflammatory factor (IL-4) level, and reduced inflammatory response, thus playing a protective role in septic AKI. Briefly, TLR4 promoted the inflammatory response in septic AKI by promoting p38 MAPK phosphorylation through MyD88/TRIF.

Pleiotrophin ameliorates white matter injury of neonatal rats by activating the mTOR/YY1/Id4 signaling pathway

Brain white matter injury (WMI) is a serious disease of the central nervous system. Pleiotrophin (PTN) promotes the differentiation and myelination of oligodendrocytes (OLs) in vitro. However, the role of PTN in WMI remains unknown. Therefore, this study aimed to investigate the neuroprotective role and potential mechanisms of PTN function in neonatal rats with WMI. The PTN and mammalian target of rapamycin (mTOR) inhibitor everolimus was used to treat a WMI model in postnatal day 3 Sprague-Dawley rats, in which the right common carotid arteries of these rats were isolated, ligated, and exposed to a hypoxic environment (6% O₂  + 94% N₂ ) for 2 h. OL differentiation and myelination, as well as the spatial learning and memory abilities of the rats were evaluated to examine the effects of PTN. Two proteins of the mTOR signaling pathway, YingYang1 (YY1) and inhibitor of DNA binding 4 (Id4), were detected and were used to explore the potential mechanisms of PTN in rat WMI experiment and oxygen glucose deprivation (OGD) model. We found that the differentiation and myelination of OLs were impaired after WMI. PTN administration rescued this injury by activating mTOR/YY1 and inhibiting Id4. Everolimus administration inhibited mTOR/YY1 and activated Id4, which blocked the neuroprotective role of PTN in WMI. PTN plays a neuroprotective role in neonatal rats with WMI, which could be involved in the mTOR/YY1/Id4 signaling pathway.

The role of pyroptosis in cognitive impairment

Cognitive impairment is a major global disease, manifests as a decline in cognitive functioning and endangers the health of the population worldwide. The incidence of cognitive impairment has increased rapidly with an increasingly aging population. Although the mechanisms of cognitive impairment have partly been elucidated with the development of molecular biological technology, treatment methods are very limited. As a unique form of programmed cell death, pyroptosis is highly pro-inflammatory and is closely associated with the incidence and progression of cognitive impairment. In this review, we discuss the molecular mechanisms of pyroptosis briefly and the research progress on the relationship between pyroptosis and cognitive impairment and its potential therapeutic values, to provide a reference for research in the field of cognitive impairment.

Effect and mechanism of chlorogenic acid on cognitive dysfunction in mice by lipopolysaccharide-induced neuroinflammation

Background

Neuroinflammation is an important factor causing numerous neurodegenerative pathologies. Inflammation can lead to abnormal neuronal structure and function and even death, followed by cognitive dysfunction. There is growing evidence that chlorogenic acid has anti-inflammatory effects and immunomodulatory activity.

Purpose

The aim of this study was to elucidate the potential targets and molecular mechanisms of chlorogenic acid in the treatment of neuroinflammation.

Methods

We used the lipopolysaccharide-induced neuroinflammation mouse model and the lipopolysaccharide-stimulated BV-2 cells in vitro model. Behavioral scores and experiments were used to assess cognitive dysfunction in mice. HE staining and immunohistochemistry were used to assess neuronal damage in the mouse brain. Immunofluorescence detected microglia polarization in mouse brain. Western blot and flow cytometry detected the polarization of BV-2 cells. The migration of BV-2 cells was detected by wound healing assay and transwell assay. Potential targets for chlorogenic acid to exert protective effects were predicted by network pharmacology. These targets were then validated using molecular docking and experiments.

Results

The results of in vivo experiments showed that chlorogenic acid had an obvious ameliorating effect on neuroinflammation-induced cognitive dysfunction. We found that chlorogenic acid was able to inhibit BV-2 cells M1 polarization and promote BV-2 cells M2 polarization in vitro while also inhibiting the abnormal migration of BV-2 cells. Based on the network pharmacology results, we identified the TNF signaling pathway as a key signaling pathway in which chlorogenic acid exerts anti-neuroinflammatory effects. Among them, Akt1, TNF, MMP9, PTGS2, MAPK1, MAPK14, and RELA are the core targets for chlorogenic acid to function.

Conclusion

Chlorogenic acid can inhibit microglial polarization toward the M1 phenotype and improve neuroinflammation-induced cognitive dysfunction in mice by modulating these key targets in the TNF signaling pathway.

Inhibition of interleukin-6 trans-signaling improves survival and prevents cognitive impairment in a mouse model of sepsis

Sepsis-associated encephalopathy (SAE) manifests clinically as acute and chronic cognitive impairments, which is associated with increased morbidity and mortality. Interleukin-6 (IL-6), a pro-inflammatory cytokine, is consistently up-regulated in sepsis. IL-6 initiates proinflammatory effects after binding to soluble IL-6 receptor (IL-6R) through trans-signalling, which requires the transducer gp130. In this study, we investigated whether inhibition of IL-6 trans-signalling is a putative therapeutic target for sepsis and SAE. Twenty-five patients (12 septic and 13 non-septic patients) were recruited for the study. A significant increase of IL-6, IL-1β, IL-10, and IL-8 was observed in the septic patients 24 h after ICU admission. In animal study, cecal ligation and puncture (CLP) was used to induce sepsis in male C57BL/6J mice. One hour before or after inducing sepsis, mice were treated with sgp130, a selective IL-6 trans-signaling inhibitor, respectively. Survival rate, cognition, levels of inflammatory cytokines, integrity of blood-brain barrier (BBB), and oxidative stress were assessed. In addition, immune cells activation and transmigration were evaluated in peripheral blood and brains. Sgp130 improved survival rate and cognitive functions, reduced levels of inflammatory cytokines, including IL-6, TNF-α, IL-10, and MCP-1, in plasma and hippocampus (hipp), mitigated BBB disruption, and ameliorated sepsis-induced oxidative stress. Sgp130 also affected monocytes/macrophages and lymphocytes transmigration and activation in septic mice. Our results indicate that selective inhibition of IL-6 trans-signaling by sgp130 exerts protective effects against SAE in a mouse model of sepsis, suggesting a potential therapeutic strategy.

Parecoxib attenuates inflammation injury in septic H9c2 cells by regulating the MAPK signaling pathway

Parecoxib, a non-steroidal anti-inflammatory drug, has been reported to possess protective effects against sepsis. However, its detailed role and underlying mechanisms in septic cardiomyopathy remain unclear. Therefore, the goal of the present study was to clarify the function and to investigate the mechanisms of parecoxib in lipopolysaccharide (LPS)-treated H9c2 rat cardiomyocytes. TNF-α, IL-1β and IL-6 expression levels in parecoxib-treated H9c2 cells stimulated with LPS were assessed using ELISA. Parecoxib-treated H9c2 cells stimulated with LPS were tested for viability using the Cell Counting Kit-8 assay. Western blotting analysis and 5-ethynyl-2'-deoxyuridine were used to evaluate cell proliferation. Apoptosis was assessed using TUNEL and western blotting. To assess the protein expression of the MAPK signaling pathway, western blotting was performed. The data showed that parecoxib significantly and dose-dependently reduced the inflammatory responses of LPS-treated H9c2 cells. Parecoxib also significantly and dose-dependently increased the proliferation and inhibited the apoptosis of LPS-treated H9c2 cells. In addition, parecoxib significantly suppressed the activation of the MAPK (p38, JNK and ERK) signaling pathway. The current study indicated that parecoxib could be a viable therapeutic option for septic cardiomyopathy.

A MODIFIED SURGICAL SEPSIS MODEL SATISFYING SEPSIS-3 AND HAVING HIGH CONSISTENCY OF MORTALITY

ABSTRACT

Background : Cecal ligation and perforation (CLP) is currently considered the criterion standard model of sepsis; however, there are some deficiencies, such as low clinical relevance, inconsistency in severity grading, and an unknown proportion of CLP animals meeting the requirements of sepsis-3. Methods : Adult rats were randomly divided into the following three groups: modified CLP (M-CLP) group, CLP group, and sham group. The vital organ function of rats was evaluated 24 hours postoperatively by blood pressure, behavioral testing, histopathology, and blood test. Cytokine levels were determined by enzyme-linked immunosorbent assay, and T-cell suppression was assessed by flow cytometry. The stability of the model was evaluated by comparing the survival rates of repeated experiments in all groups from day 1 to day 14. Results : More rats in the M-CLP group met Sepsis-3 criteria than those in the CLP group 24 hours postoperatively (53.1% vs. 21.9%, P = 0.01). Rats in the M-CLP group developed more serious hepatic, pulmonary, and renal dysfunction. Similar to human sepsis, rats in the M-CLP group demonstrated more serious immunosuppression and systemic inflammation compared with the CLP group. In addition, disease development and severity, which was indicated by the stable survival rates of model animals, were more stable in the M-CLP group. Conclusions : More rats could meet Sepsis-3 criteria with this novel surgical procedure, which may reduce the number of animals needed in preclinical sepsis experiments. This stable M-CLP model may contribute to the development of new therapies.

Core genes in lung adenocarcinoma identified by integrated bioinformatic analysis

This study aims to identify potential core genes of lung adenocarcinoma (LUAD). Three datasets (GSE32863, GSE43458, and GSE116959) were retrieved from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) between LUAD and normal tissues were filtrated by GEO2R tool. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were performed via Metascape database. The protein-protein interaction (PPI) network was constructed and core genes were identified using STRING and Cytoscape. Core genes expressions and their relevant clinical characteristics were performed via Oncomine and UALCAN databases respectively. The correlation between core genes and immune infiltrates was investigated by TIMER database. Kaplan-Meier plotter was performed for survival analysis. The signal pathway network of core genes was mapped by KEGG Mapper analysis tool. In this study, ten core genes were significantly related to overall survival (OS) of LUAD patients, which can provide clues for prognosis of LUAD.

Acetaldehyde dehydrogenase 2 activation attenuates sepsis-induced brain injury through NLRP3 inflammasome regulation

OBJECTIVE

Acetaldehyde dehydrogenase 2 (ALDH2) plays an important part in neuroprotection; however, its effect on sepsis-induced brain injury is nuclear. Our aim is to investigate the potential effect and mechanism of ALDH2 in this condition.

METHODS

We established an animal model using cecal ligation and perforation (CLP). Twenty-four rats were divided into sham group (n = 6), CLP group (n = 6), CLP + Alda-1 group (n = 6) and CLP + Cyanamide (CYA) group (n = 6). Vital signs were monitored, and arterial blood gas analysis, hippocampal histological staining and ALDH2 activity analysis were conducted. Western blot analysis and enzyme-linked immunosorbent assays were also carried out. Lipopolysaccharide (LPS)-treated HT22 cells were employed as an in vitro model of sepsis-induced brain injury, with and without pretreatment with Alda-1 or CYA, to further examine the potential mechanisms. Real-time quantitative polymerase chain reaction and western blot were used to determine the levels of pyrin domain-containing 3 (NLRP3) inflammasome.

RESULTS

We found hippocampal cell injury in the CLP group (p < 0.05), with decreased ALDH2 activity (p < 0.05) and suspected overexpression of NLRP3/caspase-1 axis (p < 0.05). In the group pretreated with Alda-1, there were increased ALDH2 activity (p < 0.05), decreased hippocampal cell damage (p < 0.05), and reduced protein levels of NLRP3, apoptosis-associated speck like protein containing a caspase recruitment domain (ASC), cleaved caspase-1 and Gasdermin D (GSDMD) (p < 0.05). The levels of interleukin 18 (IL-18) and interleukin 1β (IL-1β) were also reduced (p < 0.05). In the group pretreated with CYA, ALDH2 activity was further declined, the cell injury grade increased, and the elevated levels of pyroptosis-related proteins aggravated (p < 0.05). LPS treatment decreased the cell viability and ALDH2 activity of the HT22 cells (p < 0.05), along with increased mRNA levels of the NLRP3 inflammasome, as well as IL-1β and IL-18 (p < 0.05). Western blot further revealed elevated levels of NLRP3, ASC, cleaved caspase-1 and GSDMD (p < 0.05). In the LPS+Alda-1 group, there were increased cell viability (p < 0.05), elevated ALDH2 activity (p < 0.05), and reduced levels of NLRP3 inflammasome and pyroptosis-related proteins (p < 0.05). In the CYA+LPS group, cell viability and ALDH2 activity were further declined (p < 0.05), while levels of NLRP3 /caspase-1 axis were increased (p < 0.05).

CONCLUSIONS

The activation of ALDH2 can attenuate sepsis-induced brain injury, hypothetically through regulation of the NLRP3/caspase-1 signaling pathway. Therefore, ALDH2 could potentially be considered as a new therapeutic target for the treatment of sepsis-induced brain injury.

ASGR1 promotes liver injury in sepsis by modulating monocyte-to-macrophage differentiation via NF-κB/ATF5 pathway

AIMS

Liver is a pivotal organ for sepsis-induced injury and approximately 40 % of liver injury results from sepsis. During hepatic injury, monocyte-to-macrophage differentiation is a key event because it results in the regulation of immune response. Asialoglycoprotein receptor 1 (ASGR1) is enriched in classical monocyte of peripheral blood mononuclear cells (PBMCs). We aimed to explore the effect of ASGR1 on monocyte-to-macrophage differentiation and the modulation of sepsis-induced liver injury.

MAIN METHODS

ASGR1-knockdown/overexpression THP-1 cells and mice bone marrow-derived macrophages (BMDMs) induced by PMA and 30 % L929-cell conditioned medium were utilized to test the impact of ASGR1 on monocyte-to-macrophage differentiation and molecular mechanism respectively. Expression of differentiation specific factors were assessed via flow cytometry and real-time quantitative PCR. RNA-sequencing (RNA-seq) analysis revealed the effect of ASGR1 on monocyte-to-macrophage differentiation. Further, differentiation specific factors ATF5 and NF-κB pathways were examined via Western blot. The interaction between ASGR1 and ATF5 was further examined by co-IP. Finally, LPS-induced ASGR1-knockdown mice sepsis was used to investigate the effect of ASGR1 on monocyte-to-macrophage differentiation, liver injury and survival.

KEY FINDINGS

ASGR1 promoted monocyte-to-macrophage differentiation via up-regulating CD68, F4/80 and CD86. Additionally, inhibited-ASGR1 decreased ATF5 expression by suppressing phosphorylation of NF-κB and IKBa in vitro and in vivo. ASGR1-knockdown mice suppressed Ly6C^hi inflammatory monocytes in PBMCs, and restrained CD45⁺CD11b^hiF4/80⁺Ly6C^lo monocyte-derived macrophages and CD45⁺CD11b⁺F4/80⁺Ly6C⁺ inflammatory macrophages in livers. It also suppressed the level of IL-1β, IL-6, TNF-α and alleviated liver injury and improved survival after sepsis.

SIGNIFICANCE

ASGR1 is a negative regulator for sepsis-induced liver injury and survival.

Lentinan improves intestinal inflammation and gut dysbiosis in antibiotics-induced mice

Gut microbiota dysbiosis is already a global problem after antibiotic overuse. This study was to investigate the therapeutic effect of lentinan and the mechanism of recovery of intestinal inflammation on broad-spectrum antibiotic-driven gut microbial dysbiosis in mice. Gut microbiota was elucidated by the Illumina MiSeq platform. Gas chromatography/mass spectrometry was used to investigate short-chain fatty acid content. Colon histology, expression of tight-junction associated proteins and pro-inflammatory cytokines levels were evaluated. The results showed that the gut microbiota of diversity and richness were reduced and various taxonomic levels of the gut microbiota were perturbed after antibiotics gavage. The abundance of Firmicutes and Bacteroidetes shifted to Proteobacteria and increased the relative abundance of harmful microbiota (Parabacteroides and Klebsiella) post-antibiotics, whereas lentinan administration reversed the dysbiosis and increased beneficial microbiota, including S24-7, Lactobacillus, Oscillospira, Ruminococcus and Allobaculum. The concentrations of propionic acid and butyric acid were significantly increased by treatment with lentinan. And lentinan improved colon tissue morphology and reduced pro-inflammatory cytokines via altering NF-κB signaling pathway in antibiotic-driven gut microbial dysbiosis mice. Taken together, the results proved that lentinan can be used as a prebiotic and the result provided a theoretical basis for improving the clinical treatment of broad-spectrum antibiotics side effects.

Protective effect of Monarda didymaL. essential oil and its main component thymol on learning and memory impairment in aging mice

The aging process of human beings is accompanied by the decline of learning and memory ability and progressive decline of brain function, which induces Alzheimer’s Disease (AD) in serious cases and seriously affects the quality of patient’s life. In recent years, more and more studies have found that natural plant antioxidants can help to improve the learning and memory impairment, reduce oxidative stress injury and aging lesions in tissues. This study aimed to investigate the effect of Monarda didymaL. essential oil and its main component thymol on learning and memory impairment in D-galactose-induced aging mice and its molecular mechanism. The composition of Monarda didymaL. essential oil was analyzed by Gas Chromatography-Mass Spectrometer (GC-MS). A mouse aging model was established by the subcutaneous injection of D-galactose in mice. The behavior changes of the mice were observed by feeding the model mice with essential oil, thymol and donepezil, and the histopathological changes of the hippocampus were observed by HE staining. And the changes of acetylcholinesterase (AchE), superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX) activities, and the content of malondialdehyde (MDA) in hippocampal tissues were detected by corresponding kits. The expression of mitogen activated protein kinase (MAPK) and nuclear factor E2 related factor 2 (Nrf2) pathways related proteins were detected by western blot. Animal experimental results showed that compared with model group, the above indexes in Monarda didymaL. essential oil and thymol groups improved significantly in a dose-dependent manner. Monarda didymaL. essential oil and its main active component thymol can improve the learning and memory impairment of aging mice to some extent, and Nrf2 and MAPK pathways may be involved in its action process.

Dioscin ameliorates cisplatin-induced intestinal toxicity by mitigating oxidative stress and inflammation

Cisplatin is the most widely prescribed drug in chemotherapy, but its gastrointestinal toxicity reduces therapeutic efficacy. Oxidative stress and inflammation are considered to be the main pathogenesis of cisplatin-induced intestinal toxicity. Dioscin is a steroidal saponin with potential anti-cancer, antioxidant, and anti-inflammatory activities. In this study, we established a rat model of intestinal injury by tail vein injection of cisplatin, and intragastrically administered dioscin to evaluate its effect on intestinal injury. Biochemical markers, western blotting, qRT-PCR and histopathological staining were used to analyze intestinal injury according to various molecular mechanisms. The results revealed that dioscin significantly inhibited cisplatin-induced intestinal mucosal damage and decreased DAO levels in rats. Furthermore, dioscin activated the Nrf2/HO-1 pathway to increase the level of antioxidant enzymes and reduce the levels of MDA and H₂O₂. In addition, dioscin pretreatment significantly reduced ileum epithelial NLRP3 inflammasome formation and decreased the levels of inflammatory factors compared with the cisplatin group. In parallel, Nrf2 inhibitor ML385 blocked the therapeutic effect of dioscin in rat with cisplatin-induced intestinal toxicity. In terms of mechanisms, dioscin reversed cisplatin-induced up-regulation of MAPKs and up-regulated p-PI3K and p-AKT levels. Meanwhile, dioscin potently promoted Wnt3A/β-catenin signaling to relieve cisplatin-induced proliferation inhibition. In conclusion, our study suggests that dioscin could ameliorate the cisplatin-induced intestinal toxicity by reducing oxidative stress and inflammation.

Molecular mechanisms and functions of pyroptosis in sepsis and sepsis-associated organ dysfunction

Sepsis, a life-threatening organ dysfunction caused by a dysregulated host response to infection, is a leading cause of death in intensive care units. The development of sepsis-associated organ dysfunction (SAOD) poses a threat to the survival of patients with sepsis. Unfortunately, the pathogenesis of sepsis and SAOD is complicated, multifactorial, and has not been completely clarified. Recently, numerous studies have demonstrated that pyroptosis, which is characterized by inflammasome and caspase activation and cell membrane pore formation, is involved in sepsis. Unlike apoptosis, pyroptosis is a pro-inflammatory form of programmed cell death that participates in the regulation of immunity and inflammation. Related studies have shown that in sepsis, moderate pyroptosis promotes the clearance of pathogens, whereas the excessive activation of pyroptosis leads to host immune response disorders and SAOD. Additionally, transcription factors, non-coding RNAs, epigenetic modifications and post-translational modifications can directly or indirectly regulate pyroptosis-related molecules. Pyroptosis also interacts with autophagy, apoptosis, NETosis, and necroptosis. This review summarizes the roles and regulatory mechanisms of pyroptosis in sepsis and SAOD. As our understanding of the functions of pyroptosis improves, the development of new diagnostic biomarkers and targeted therapies associated with pyroptosis to improve clinical outcomes appears promising in the future.

The traditional Chinese patented medicine Qingke Pingchuan granules alleviate acute lung injury by regenerating club cells

Qingke Pingchuan granules (QKPCG), a patented traditional Chinese medicine, clinically, are recommended for acute tracheobronchitis, cough, community-acquired pneumonia, and other respiratory diseases. However, its potential protective effect and mechanism of action in acute lung injury (ALI) have not been explored. We aimed to explore the mechanisms underlying the protective role of QKPCG in ALI. The therapeutic efficacy of QKPCG was investigated in a lipopolysaccharide (LPS)-induced ALI mouse model. Mice were divided into three groups, namely, the Control, LPS, and LPS + QKPCG groups. Mice in the LPS + QKPCG group were administered QKPCG intragastrically as a treatment once a day for a total of three days. QKPCG effectively increased survival and reduced lung injury in treated mice. It significantly reduced the LPS-induced expression of interleukin (IL)-6, tumor necrosis factor-α (TNF-α), IL-1α, and IL-1β. RNA-sequencing followed by real-time quantitative polymerase chain reaction validation suggested a critical role of the secretoglobin family 1A member 1 (Scgb1a1) gene in mediating the protective effect of QKPCG. Further, QKPCG reversed the LPS-induced downregulation of the Clara cell 10 kDa protein (CC10), a pulmonary surfactant protein encoded by Scgb1a1, which is mainly secreted by club cells in the lungs. Exogenous supplementation of CC10 alleviated LPS-induced ALI. Hematoxylin and eosin staining and enzyme-linked immunosorbent assay results further confirmed the anti-inflammatory properties of CC10, which were suggested as mediated via the inhibition of NFκB phosphorylation. In summary, our study provides evidence of the beneficial role of QKPCG in alleviating lung injury, mediated via the decreased disruption of club cells and higher expression of CC10, which leads to NFκB pathway inhibition.

Scorpion and centipede alleviates severe asthma through M2 macrophage-derived exosomal miR-30b-5p

Asthma is one of the most common chronic inflammatory diseases. Although the scorpion and centipede (SC) significantly ameliorates asthma and changes exosomal miRNAs, the molecular mechanism is still obscure. Here, we show that SC improves inflammation in asthmatic mice and increases M2 macrophage-derived exosomes (M2Φ-Exos) by promoting M2 macrophage polarization. The M2Φ-Exos remarkably inhibits airway epithelial cell pyroptosis by reducing the expression of NLRP3, caspase-1, and LI-1β and mitochondrial swelling. Furthermore, miR-30b-5p is up-regulated in M2Φ-Exos compared with M1Φ-Exos. Overexpression of miR-30b-5p in M2Φ-Exos prevents airway epithelial cell pyroptosis, while down-regulation of miR-30b-5p promotes pyroptosis. We also uncover that pyroptosis is increased in asthmatic mice, while SC blocks pyroptosis. Moreover, miR-30b-5p overexpressed M2Φ-Exos further enhances the ameliorative effect of SC, which significantly down-regulates IRF7 expression. Our results collectively reveal that M2Φ-Exos induced by SC could carry miR-30b-5p to mitigate severe asthma by inhibiting airway epithelial cell pyroptosis. Most importantly, our findings may provide a potential clinical application of M2Φ-Exos for treating severe asthma.

Preexposure to heat stress attenuates sepsis-associated inflammation and cognitive decline in rats

Sepsis is a life-threatening organ dysfunction due to an infection, leading to cognitive impairments. Studies have shown that heat shock protein 70 (HSP70) exhibited a neuroprotective effect. In this study we used mild heat stress to induce expression of HSP70, aimimg to detect the effect of HSP70 on neurocognitive deficits associated with sepsis and explored the underlying mechanisms. Male rats were exposed to 42℃ for 15 min. After 12 hours, they were subjected to cecal ligation and puncture (CLP). HSP70 and brain-derived neurotrophic factor (BDNF) expression, nuclear level of NF-level of NF-trophic factor (BDNF)ed by western blot. Levels of inflammatory cytokines in circulation and hippocampus were measured by ELISA and RT-PCR. Neuronal morphology and damage of hippocampal neurons were assessed by Hematoxylin-Eosin (HE) and Nissl stainings. Microglial activation was determined by immunohistochemistry. Finally, neurologic and cognitive functions were evaluated using neurobehavioral scoring and morris water maze (MWM) test. Mild heat stress increased survival rate of sepsis rats. Mild heat stress upregulated HSP70, inhibited nuclear level of NF-κB p65 in hippocampus. Mild heat stress could diminish IL-1β and TNF-α levels in circulation and hippocampus. Furthermore, mild heat stress was able to enhance expression of BDNF and alleviate cognitive impairment after sepsis. Overall, these results indicated that mild heat stress showed protective effects on sepsis-associated encephalopathy rat model, which may be associated with upregulation of HSP70 and inhibition of NF-κB pathway.

Improved Sleep, Memory, and Cellular Pathological Features of Tauopathy, Including the NLRP3 Inflammasome, after Chronic Administration of Trazodone in rTg4510 Mice

Several cellular pathways contribute to neurodegenerative tauopathy-related disorders. Microglial activation, a major component of neuroinflammation, is an early pathologic hallmark that correlates with cognitive decline, while the unfolded protein response (UPR) contributes to synaptic pathology. Sleep disturbances are prevalent in tauopathies and may also contribute to disease progression. Few studies have investigated whether manipulations of sleep influence cellular pathologic and behavioral features of tauopathy. We investigated whether trazodone, a licensed antidepressant with hypnotic efficacy in dementia, can reduce disease-related cellular pathways and improve memory and sleep in male rTg4510 mice with a tauopathy-like phenotype. In a 9 week dosing regimen, trazodone decreased microglial NLRP3 inflammasome expression and phosphorylated p38 mitogen-activated protein kinase levels, which correlated with the NLRP3 inflammasome, the UPR effector ATF4, and total tau levels. Trazodone reduced theta oscillations during rapid eye movement (REM) sleep and enhanced REM sleep duration. Olfactory memory transiently improved, and memory performance correlated with REM sleep duration and theta oscillations. These findings on the effects of trazodone on the NLRP3 inflammasome, the unfolded protein response and behavioral hallmarks of dementia warrant further studies on the therapeutic value of sleep-modulating compounds for tauopathies.SIGNIFICANCE STATEMENT Dementia and associated behavioral symptoms such as memory loss and sleep disturbance are debilitating. Identifying treatments that alleviate symptoms and concurrently target cellular pathways contributing to disease progression is paramount for the patients and their caregivers. Here we show that a chronic treatment with trazodone, an antidepressant with positive effects on sleep, has beneficial effects on several cellular pathways contributing to neuroinflammation and tau pathology, in tauopathy-like rTg4510 mice. Trazodone also improved rapid eye movement (REM) sleep, the slowing of brain oscillations, and olfactory memory disturbances, which are all early symptoms observed in Alzheimer's disease. Thus, trazodone and compounds with REM sleep-promoting properties may represent a promising treatment approach to reduce the early symptoms of tauopathy and slow down disease progression.

Polydatin Improves Sepsis-Associated Encephalopathy by Activating Sirt1 and Reducing p38 Phosphorylation

INTRODUCTION

Our previous study confirmed that polydatin (PD) can alleviate sepsis-induced multiorgan dysfunction (in the vascular endothelium, kidney, and small intestine) by activating Sirt1 and that PD protects against traumatic brain injury in rats via increased Sirt1 and inhibition of the p38-mediated mitogen-activated protein kinase (MAPK) pathway. We aim to investigate whether PD may also attenuate sepsis-associated encephalopathy (SAE).

METHODS

In this study, we constructed an SAE mouse model by cecal ligation and puncture (CLP) and measured Sirt1 protein activity, p38 phosphorylation, brain tissue pathological damage, pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6), mitochondrial function (mitochondrial membrane potential, ATP content, and reactive oxygen species), neurological function, and animal survival time. Sirt1 selective inhibitor Ex527 and p38 inhibitor SB203580 were used to explore the possible mechanism of PD in SAE.

RESULTS

We confirmed that PD inhibits neuroinflammation evidenced by reduced proinflammatory cytokines. In addition, PD protects mitochondria as demonstrated by restored mitochondrial membrane potential and adenosine triphosphate (ATP) content, and decreased reactive oxygen species (ROS) level. As we expected, p38 inhibition reduces neuroinflammation and mitochondrial damage. In contrast, Sirt1 inhibition aggravates cerebral cortex mitochondrial damage and neuroinflammation and promotes phosphorylation of p38. Mechanistically, PD treatment suppressed p38 phosphorylation and consequently reduced the neuroinflammatory response, and these effects were blocked by the Sirt selective inhibitor Ex527.

CONCLUSIONS

This study, to the best of our knowledge, is the first to demonstrate that PD alleviates SAE, at least partially, by upregulating Sir1-mediated neuroinflammation inhibition and mitochondrial function protection.

Utilising Network Pharmacology to Explore Underlying Mechanism of Astragalus membranaceus in Improving Sepsis-Induced Inflammatory Response by Regulating the Balance of IκBα and NF-κB in Rats

Objective

The purpose of the present study was to explore the mechanism of Astragalus membranaceus in the treatment of sepsis.

Methods

We searched the active components and targets of Astragalus membranaceus using the TCMSP and BATMAN databases. Then, the GeneCards, MalaCards, and OMIM databases were used to screen out relevant targets of sepsis. The common targets of the former two gene sets were uploaded to the STRING database to create an interaction network. DAVID was used to perform KEGG enrichment analysis of the core targets. Based on the results of KEGG and previous studies, key pathways for the development of sepsis were identified and experimentally validated.

Result

We obtained 3,370 sepsis-related targets in databases and 59 active components in Astragalus membranaceus through data mining, corresponding to 1,130 targets. The intersection of the two types of targets led to a total of 318 common targets and 84 core targets were obtained after screening again. The KEGG and previous studies showed that these 84 core targets were involved in sepsis by regulating TNF, MAPK, and PI3K pathways. TNF, MAPK8, NF-κB, and IκBα are crucial in sepsis. Experimental validation demonstrated that some markers in sepsis model rats were improved after the intervention with Astragalus granules and their chemical components. Among them, IL-1β, IL-6, and TNF-α in rat serum were reduced. The mRNA and protein expression of TNF-α, IL-6, MMP9, MAPK8, and NF-κB were reduced in rat blood. However, the mRNA and protein expression of IκBα and PI3K were increased in rat blood.

Conclusion

The AST could affect the TNF, PI3K, and MAPK pathway cascade responses centred on IκBα and NF-κB, attenuate the expression of IL-6 and MMP9, and interfere with the inflammatory response during sepsis.

A new cell death program regulated by toll-like receptor 9 through p38 mitogen-activated protein kinase signaling pathway in a neonatal rat model with sepsis associated encephalopathy

Background:

Sepsis, a serious condition with high mortality, usually causes sepsis associated encephalopathy (SAE) that involves neuronal cell death. However, the cell death programs involved and their underlying mechanisms are not clear. This study aimed to explore the regulatory mechanisms of different cell death programs in SAE.

Methods:

A neonatal rat model of SAE was established by cecal ligation and perforation. Survival rate and vital signs (mean arterial pressure and heart rate) were monitored, nerve reflexes were evaluated, and cortical pathological changes were observed by hematoxylin and eosin staining. The expression of pyroptosis, apoptosis, and necroptosis (PANoptosis)-related proteins, mitogen- activated protein kinase (MAPK), and its upstream regulator toll-like receptor 9 (TLR9) were detected. The expression of TLR9 in neurons was observed by immunofluorescence staining. The ultrastructure of neurons was observed by transmission electron microscope.

Results:

First, PANoptosis was found in cortical nerve cells of the SAE rats. Meanwhile, the subunits of MAPKs, p38 MAPK, Jun N- terminal kinase, and extracellular signal-regulated kinase (ERK) were activated. After pharmacologically inhibiting each of the subunits, only p38 MAPK was found to be associated with PANoptosis. Furthermore, blocking the p38 MAPK signaling pathway activated necroptosis but inhibited apoptosis and pyroptosis. When necroptosis was pharmacologically inhibited, apoptosis and pyroptosis were reactivated. Finally, we found that the expression of TLR9, a regulator of MAPKs, was significantly increased in this model. After down-regulation of TLR9, p38 MAPK, and ERK signaling pathways were inhibited, which led to the inhibition of PANoptosis. Further analysis found that down-regulation of TLR9 improved the survival rate and reduced the pathological changes in SAE rats.

Conclusions:

Our study showed that the programs comprising PANoptosis are activated simultaneously in SAE rats. TLR9 activated PANoptosis through the p38 MAPK signaling pathway. TLR9 may work as a potential target for SAE treatment.