LPS-induced Injury Research Articles

FTO attenuates LPS-induced acute kidney injury by inhibiting autophagy via regulating SNHG14/miR-373-3p/ATG7 axis

N6‐methyladenosine (m6A) is a master driver of RNA function and implicates in the pathogenesis of renal injury. LncRNA SNHG14 is highly expressed in sepsis patients with acute kidney injury (AKI) and aggravates kidney cell dysfunction. This study aimed to explore whether demethylase FTO affect m6A methylation of SNHG14 in AKI injury and its underlying mechanism. The expression level of FTO was obviously downregulated in sepsis-associated AKI patients compared with normal controls. Mechanistically, FTO overexpression impeded SNHG14 expression by decreasing the stability of SNHG14 in an m6A-dependent manner in LPS-induced HK-2 cells. Additionally, FTO overexpression inhibited cell autophagy and apoptosis while promoting cell viability of LPS-induced HK-2 cells. Moreover, overexpression of FTO inhibited SNHG14 expression and autophagy in LPS-induced AKI mice. Functionally, SNHG14 acts as a competing endogenous RNA (ceRNA) via directly sponging miR-373-3p in LPS induced HK-2 cells. Additionally, miR-373-3p directly targets ATG7. Inhibition of SNHG14 suppresses NF-κB signaling pathway and production of inflammatory cytokines (TNF-α, IL-6, and IL-1β) via miR-373-3p/ATG7 in LPS-induced HK-2 cells. Furthermore, the SNHG14/miR-373-3p/ATG7 interaction network contributes to the regulatory effect of FTO on LPS-induced HK-2 cell viability, apoptosis and autophagy. These results suggested demethylase FTO suppressed the m6A modification of lncRNA SNHG14 and inhibits autophagy in LPS-induced AKI via regulating miR-373-3p/ATG7, which provided an important novel perspective for understanding sepsis-associated AKI and is conducive for developing new therapeutic targets and strategies.

Baicalin attenuates lipopolysaccharide-induced intestinal inflammatory injury via suppressing PARP1-mediated NF-κB and NLRP3 signalling pathway

Bacterial lipopolysaccharide (LPS) exposure is a key inducer of intestinal inflammatory injury in weaned piglets, resulting in decreased growth performance of pigs and causing severe economic losses to the swine industry; however, the mechanism of intestinal inflammatory injury is still unclear. Baicalin is one of the main active ingredients extracted from the natural plant Scutellaria baicalensis that has biological functions, including anti-inflammatory activity. The aim of this study is to investigate the effect and mechanism of baicalin intervention on intestinal inflammatory injury caused by bacterial LPS exposure. In the present study, network pharmacology, molecular docking and DARTS results identified that baicalin has the potential to target PARP1, thereby potentially regulating a series of inflammation-related pathways, including the MAPK, NF-κB and Toll-like receptor signalling pathways, which play the role of antagonizing LPS-induced intestinal inflammatory injury. Further application of the LPS-induced IPEC-J2 cell model validated the finding that baicalin could alleviate LPS-induced intestinal inflammatory injury by inhibiting the PARP1-mediated NF-κB and NLRP3 signalling pathway. These findings demonstrate that baicalin can regulate the expression of PARP1 and that PARP1 has the potential to serve as an effective therapeutic target in the LPS-induced intestinal inflammatory injury.

Circ_0006640 transferred by bone marrow-mesenchymal stem cell-exosomes suppresses lipopolysaccharide-induced apoptotic, inflammatory and oxidative injury in spinal cord injury

BackgroundEmerging proofs have shown that differentially expressed circular RNAs (circRNAs) are closely associated with the pathophysiological process of spinal cord injury (SCI). Mesenchymal stem cell (MSC)-exosomes have been demonstrated to possess favorable therapeutic effects in diseases. Herein, this work aimed to investigate the action of circ_0006640 transferred by MSC-exosomes functional recovery after SCI.MethodsSCI animal models were established by spinal cord contusion surgery in mice and lipopolysaccharide (LPS)-stimulated mouse microglial cell line BV2. Levels of genes and proteins were detected by qRT-PCR and Western blot. Properties of BV2 cells were characterized using CCK-8 assay, flow cytometry and ELISA analysis. The oxidative stress was evaluated. Dual-luciferase reporter assay was used for verifying the binding between miR-382-5p and circ_0006640 or IGF-1 (Insulin-like Growth Factor 1). Exosome separation was conducted by using the commercial kit.ResultsCirc_0006640 expression was lower in SCI mice and LPS-induced microglial cells. Circ_0006640 overexpression protected microglial cells from LPS-induced apoptotic, inflammatory and oxidative injury. Mechanistically, circ_0006640 directly sponged miR-382-5p, which targeted IGF-1. MiR-382-5p was increased, while IGF-1 was decreased in SCI mice and LPS-induced microglial cells. Knockdown of miR-382-5p suppressed apoptosis, inflammation and oxidative stress in LPS-induced microglial cells, which were reversed by IGF-1 deficiency. Moreover, miR-382-5p up-regulation abolished the protective functions of circ_0006640 in LPS-induced microglial cells. Additionally, circ_0006640 was packaged into MSC-exosomes and could be transferred by exosomes. Exosomal circ_0006640 also had protective effects on microglial cells via miR-382-5p/IGF-1 axis.ConclusionCirc_0006640 transferred by BMSC-exosomes suppressed LPS-induced apoptotic, inflammatory and oxidative injury via miR-382-5p/IGF-1 axis, indicating a new insight into the clinical application of exosomal circRNA-based therapeutic in the function recovery after SCI.

Alpinetin alleviates LPS-induced lung epithelial cell injury by inhibiting p38 and ERK1/2 signaling via aquaporin-1

Alpinetin has been reported to play a protective role in lung diseases, while its special mechanisms remain indistinct. In this study, acute lung injury (ALI) model was constructed by inducing MLE-12 cells with lipopolysaccharide (LPS). Cell activity together with apoptosis was judged employing cell counting kit-8 (CCK-8), flow cytometry along with western blot. Oxidative stress levels were measured by dichloro-dihydro-fluorescein diacetate (DCFH-DA) staining and corresponding kits. In addition, enzyme-linked immunosorbent assay (ELISA) was to examine the levels of inflammatory factors. The protein expressions of aquaporin-1 (AQP1), p38 and extracellular signal-regulated kinase (ERK) 1/2 pathway were estimated utilizing western blot. The data showed that alpinetin increased the viability, reduced the apoptosis, oxidative stress and inflammation and inactivated p38 and ERK1/2 signaling in LPS-induced MLE-12 cells. Moreover, alpinetin also increased AQP1 expression and AQP1 knockdown reversed the impacts of alpinetin on LPS-induced MLE-12 cells. Additionally, AQP1 agonist AqF026 also exerted anti-apoptotic and anti-inflammatory activities in LPS-treated MLE-12 cells. Evidently, alpinetin may exert its protective role in LPS-induced ALI by inactivation of p38 and ERK1/2 signaling through regulating AQP1.

Oleander attenuates hepatic inflammation in a TLR4-independent manner and by favorable modulation of hepatocellular global metabolome that supports cytoprotection

Ethnopharmacological relevanceNerium oleander is used to treat liver-associated chronic metabolic diseases in traditional medicinal systems across the globe. The hepatoprotective effects of oleander are mentioned in Indian and Chinese traditional medicinal literature. Aim of the studyThe present study aimed to investigate the cellular mechanisms behind the hepatoprotective effects of a non-toxic dose of oleander (NO). Materials and methodsThe hepatoprotective effects of NO were tested against lipopolysaccharide (LPS)-treated HepG2 cells. Oxidative stress response was studied using cellular enzymatic assays, and gene expression was analyzed using qRT-PCR. HepG2 cells were pretreated with TAK-242 (pharmacological inhibitor of TLR4) to decipher the anti-inflammatory mechanisms of NO. Cell-free metabolites were analyzed using GCMS and were subjected to pathway enrichment analysis. ResultsNO reduced systemic inflammation, serum lipid peroxidation byproducts, and glucose without affecting serum transaminase levels and hepatic histopathological features. NO attenuated the inflammation-induced loss of antioxidant enzyme activities and mRNA expressions of toll-like receptor-4 (TLR4)/nuclear factor κβ (NFκβ)-dependent inflammatory genes. In TAK-242 pretreated cells, LPS was unable to induce inflammatory and oxidative responses. However, NO treatment in TAK-242 pretreated cells with LPS stimulation further reduced the signs of inflammation and improved hepatoprotective activities. A comparative analysis of the intracellular global metabolome from HepG2 cells with and without NO treatment indicated NO-mediated favorable modulation of intracellular metabolic pathways that support cytoprotective activities. ConclusionNO protects HepG2 cells from LPS-induced oxidative and inflammatory injury. The hepatoprotective effects of NO are mediated by a TLR4-independent process and through a favorable modulation of the intracellular global metabolome that supports cytoprotection.

The in vitro anti-inflammatory mechanism of Porphyra haitanensis oligosaccharides on lipopolysaccharide-induced injury in IEC-6 cells

Porphyra haitanensis, with its rich nutritional value and distinctive flavour, has become a research hotspot in food field. P. haitanensis oligosaccharides (PHO) are oligosaccharides with potential anti-inflammatory properties that ameliorate lipopolysaccharide-induced inflammatory responses in the in vitro IEC-6 cell line model. Here, the structure of PHO was investigated, and LPS–induced injury mechanisms in IEC-6 were determined by cellular, molecular, and transcriptome analyses. After PHO exposure, LPS-induced IEC-6 cells showed reduced apoptosis, decreased oxidative stress levels, improved cell membrane integrity, and paracellular permeability. This study shows that PHO attenuates injury in the IEC-6 cell line by increasing the expression of tight junctions. PHO also inhibited the TLR4/NF-κB pathway and caused downregulation of intracellular pro-inflammatory cytokines, which attenuates LPS-induced injury in an in vitro model, and further offers the possibility of restoring the intestinal barrier. This study provides insight into the role of PHO in alleviating the intestinal epithelial barrier damage.

Fucoxanthin alleviates lipopolysaccharide-induced intestinal barrier injury in mice.

The aim of this study was to evaluate the preventive role and underlying mechanisms of fucoxanthin (Fx) on lipopolysaccharide (LPS)-induced intestinal barrier injury in mice. Our results demonstrated that the oral administration of Fx (50 and 200 mg per kg body weight per day) for consecutive 7 days significantly alleviated the severity of LPS-induced intestinal barrier injury in mice, as evidenced by attenuating body weight loss, improving intestinal permeability, and ameliorating intestinal morphological damage such as reduction in the ratio of the villus length to the crypt depth (V/C), intestinal epithelium distortion, goblet cell depletion, and low mucin 2 (MUC2) expression. Fx also significantly mitigated LPS-induced excessive apoptosis of intestinal epithelial cells (IECs) and curbed the decrease of tight junction proteins including claudin-1, occludin, and zonula occludens-1 in the ileum and colon. Additionally, Fx effectively alleviated LPS-induced extensive infiltration of macrophages and neutrophils into the intestinal mucosa, the overproduction of pro-inflammatory cytokines such as tumor necrosis factor-alpha (TNF-α), interleukin 1beta (IL-1β) and IL-6, and gasdermin D (GSDMD)-mediated pyroptosis of IECs. The underlying mechanisms might be associated with inhibiting the activation of nuclear factor-kappa B (NF-κB), mitogen-activated protein kinases (MAPKs) and nod-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome signaling pathways. Moreover, Fx also notably restrained intestinal reactive oxygen species (ROS), malondialdehyde and protein carbonylation levels in LPS-treated mice, and it might be mediated by activating the nuclear factor-erythroid 2 related factor 2 (Nrf2) signaling pathway. Overall, these findings indicated that Fx might be developed as a potential effective dietary supplement to prevent intestinal barrier injury.

Preventive effect of hyperforin on lipopolysaccharide-induced acute kidney injury and inflammation by repressing the NF-κB/miR-21 axis.

Hyperforin (HYP) has been reported to alleviate the inflammatory response. The purpose of this study was to examine the pharmacological effects of HYP on lipopolysaccharide (LPS)-induced inflammation and acute kidney injury (AKI). In vitro and in vivo septic models were created using LPS-stimulated mice podocytes and LPS-injected mice. HYP (20 mg/kg/day) or antagomiR-21 (20 nM/0.1 ml; twice/week) was administered to mitigate LPS-induced AKI and podocyte apoptosis. HYP demonstrated potential as an NF-κB inhibitor, leading to enhanced survival rates in septic mice. Moreover, HYP directly hindered LPS-induced podocyte apoptosis and AKI. The underlying mechanism involves the modulation of LPS-induced transactivation of miR-21 by NF-κB. It was observed that excessive activation of the NF-κB/miR-21 signaling axis contributed to LPS-induced podocyte apoptosis and AKI. Additionally, the absence of miR-21 expression resulted in decreased LPS-induced podocyte apoptosis and amelioration of LPS-induced renal tubular injury. The renoprotective effects of HYP were observed in septic mice through the inhibition of NF-κB/p65-mediated transactivation of miR-21. These findings suggest that targeting the NF-κB-miR-21 axis could be a potential therapeutic strategy for HYP in the prevention of AKI.

Cilostazol Combats Lipopolysaccharide-Induced Hippocampal Injury in Rats: Role of AKT/GSK3β/CREB Curbing Neuroinflammation.

Neuroinflammation is important in the pathophysiology of several degenerative brain disorders. This study looked at the potential neuroprotective benefits of cilostazol, a phosphodiesterase inhibitor, against LPS-induced hippocampus damage in rodents and the principal molecular involvement of AKT/GSK3β/CREB signaling pathways. Behavioral tests revealed that cilostazol successfully corrected LPS-induced neurobehavioral impairments. Furthermore, cilostazol therapy lowered hippocampal levels of amyloid beta 1-42 (Aβ1-42) and p-tau protein, both of which are critical pathological indicators of neurodegenerative disorders. Furthermore, cilostazol administration suppressed LPS-induced rises in hippocampus caspase-3 and NF-κB levels while elevating rat B-cell/lymphoma 2 (BCL2) and brain-derived neurotrophic factor (BDNF) levels, which are implicated in neuronal survival and synaptic plasticity. Cilostazol treatment also restored the decreased phosphorylation of protein kinase B (p-AKT) and reduced the elevated levels of phosphorylated glycogen synthase kinase-3 beta (p-GSK3β) and cAMP response element-binding protein (CREB) in the hippocampus of LPS-treated rats. Histopathological examination revealed that cilostazol ameliorated LPS-induced brain damage with reduced neuronal loss and gliosis. Immunohistochemistry analysis showed a decrease in Iba-1 expression, indicating a reduction in microglial activation in the cilostazol-treated group compared to the LPS group. The findings advocate that cilostazol exerts neuroprotective effects against LPS-induced hippocampal injury by modulating the AKT/GSK3β/CREB pathway and curbing neuroinflammation. Cilostazol may hold promise as a therapeutic agent for neuroinflammatory conditions associated with neurodegenerative diseases.

Echinatin attenuates acute lung injury and inflammatory responses via TAK1-MAPK/NF-κB and Keap1-Nrf2-HO-1 signaling pathways in macrophages.

Echinatin is an active ingredient in licorice, a traditional Chinese medicine used in the treatment of inflammatory disorders. However, the protective effect and underlying mechanism of echinatin against acute lung injury (ALI) is still unclear. Herein, we aimed to explore echinatin-mediated anti-inflammatory effects on lipopolysaccharide (LPS)-stimulated ALI and its molecular mechanisms in macrophages. In vitro, echinatin markedly decreased the levels of nitric oxide (NO) and prostaglandin E2 (PGE2) in LPS-stimulated murine MH-S alveolar macrophages and RAW264.7 macrophages by suppressing inducible nitric oxide synthase and cyclooxygenase-2 (COX-2) expression. Furthermore, echinatin reduced LPS-induced mRNA expression and release of interleukin-1β (IL-1β) and IL-6 in RAW264.7 cells. Western blotting and CETSA showed that echinatin repressed LPS-induced activation of mitogen-activated protein kinase (MAPK) and nuclear factor-kappa B (NF-κB) pathways through targeting transforming growth factor-beta-activated kinase 1 (TAK1). Furthermore, echinatin directly interacted with Kelch-like ECH-associated protein 1 (Keap1) and activated the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway to enhance heme oxygenase-1 (HO-1) expression. In vivo, echinatin ameliorated LPS-induced lung inflammatory injury, and reduced production of IL-1β and IL-6. These findings demonstrated that echinatin exerted anti-inflammatory effects in vitro and in vivo, via blocking the TAK1-MAPK/NF-κB pathway and activating the Keap1-Nrf2-HO-1 pathway.

Overexpression of the Mas1 gene mitigated LPS-induced inflammatory injury in mammary epithelial cells by inhibiting the NF-κB/MAPKs signaling pathways.

Breast infection is the primary etiology of mastitis in dairy cows, leading to a reduction in the quality of dairy products and resulting in substantial economic losses for animal husbandry. Although antibiotic treatment can eliminate the pathogenic microorganisms that induce mastitis, it cannot repair the inflammatory damage of mammary epithelial cells and blood milk barrier. Mas1 is a G protein-coupled receptor, and its role in lipopolysaccharide (LPS) -induced inflammatory injury to mammary epithelial cells has not been studied. LPS treatment of EpH4 EV cells led to a significant downregulation of Mas1 transcript levels, which attracted our great interest, suggesting that Mas1 may be an important target for the treatment of mastitis. Therefore, this study intends to verify the role of Mas1 in the inflammatory injury of EpH4 EV cells by gene overexpression technology and gene silencing technology. The findings demonstrated that the overexpression of the Mas1 gene effectively reversed the activation of the nuclear factor-κB/mitogen-activated protein kinase (NF-κB/MAPK) signaling pathways induced by LPS, while also suppressing the upregulation of pro-inflammatory mediators. Furthermore, overexpression of the Mas1 gene reversed the downregulation of zonula occludens 1 (ZO-1), Occludin, and Claudin-3 caused by LPS, suggesting that Mas1 could promote to repair the blood-milk barrier. However, the silencing of the Mas1 gene using siRNA resulted in a contrasting effect. These results indicated that Mas1 alleviated the inflammatory injury of mammary epithelial cells induced by LPS.

Huc-MSC-derived exosomal miR-144 alleviates inflammation in LPS-induced preeclampsia-like pregnant rats via the FosB/Flt-1 pathway

BackgroundPreeclampsia (PE) is a common and severe hypertensive disorder in pregnancy. Mesenchymal stem cell-derived exosomes (Exos-MSC) have been reported to mitigate the progression of inflammatory diseases. The study aimed to explore the effects of human umbilical cord-derived Exos-MSC (huc-Exos-MSC) on PE-like models. MethodsLipopolysaccharide (LPS) was used to construct in vitro and in vivo PE-like models. Exosomes were treated with LPS-induced PE-like cells and rats. ResultsPE-like inflammatory models of pregnant rats and cells were successfully constructed in vivo and in vitro. miR-144 was screened by bioinformatics analysis. Exosomes were successfully extracted. Silencing FosB, overexpressing miR-144 or treating with exosomes extracted from huc-MSC overexpressing miR-144 in (Exos-MSCmiR−144) reversed the LPS-induced decline in HTR-8/SVneo cell viability and migration. In addition, the above groups decreased LPS-induced increases in interleukin 6 (IL-6), tumor necrosis factor-α (TNF-α), phosphorylated nuclear factor-kappaB (p–NF–κB)/NF-κB, soluble FMS-like tyrosine kinase 1 (sFlt-1), and Flt-1 levels. Simultaneously, transfection of miR-144 mimics and overexpressing FosB reversed those changes in the miR-144 mimics group. miR-144 might alleviate LPS-induced HTR-8/SVneo cell inflammation by targeting FosB. Injection of Exos-MSCmiR−144 in PE-like pregnant rats reversed LPS-induced increases in FosB expression, systolic and diastolic blood pressure (SBP and DBP), as well as mean arterial pressure (MAP), heart rate, urine albumin/creatine ratio, inflammatory factors, p–NF–κB/NF-κB, and sFlt-1 levels. Furthermore, compared with the model group, the proportion of live births was significantly higher in the model + Exos-MSCmiR−144 group, while the apoptosis rate of fetal rat brain tissue was significantly lower. ConclusionsWe found that huc-Exos-MSC-derived miR-144 alleviated gestational hypertension and inflammation in PE-like pregnant rats by regulating the FosB/Flt-1 pathway. In addition, huc-Exos-MSC-derived miR-144 could partially reverse the LPS-induced adverse pregnancy outcome and brain injury in fetal rats, laying the foundation for developing new treatments for PE.

CircRSU1 alleviates LPS-induced human pulmonary microvascular endothelial cell injury by targeting miR-1224-5p/ITGA5 axis.

To investigate the potential functions and regulatory mechanism of circRSU1 on septic acute lung injury (sepsis-ALI) progression. We used lipopolysaccharide (LPS)-stimulated human pulmonary microvascular endothelial cells (HPMECs) to establish the cell model of sepsis-ALI in vitro. qRT-PCR and Western blotting were used for the detection of genes and proteins. The migration and tubulogenesis of HPMECs were assessed by transwell, wound healing, and tube formation assays. Inflammatory factors were detected by ELISA analysis. Cell permeability (PA) was determined by transendothelial resistance (TEER) and fluorescein isothiocyanate (FITC) with transwell assay. The interaction between miR-1224-5p and circRSU1 or ITGA5 (Integrin Subunit Alpha 5) was studied by dual-luciferase reporter and RNA pull-down assays. CircRSU1 expression was decreased after LPS treatment in HPMECs. Functionally, re-expression of circRSU1 in HPMECs could alleviate LPS-induced inflammatory response, the inhibition of cell migration and tube formation and enhancement of cell permeability. Mechanistically, circRSU1 acted as a sponge for miR-1224-5p. LPS treatment enhanced miR-1224-5p expression, and inhibition of miR-1224-5p reversed LPS-evoked HPMEC dysfunction mentioned above. Moreover, miR-1224-5p could abolish the protective effects of circRSU1 on HPMECs. In addition, miR-1224-5p directly targeted ITGA5, and circRSU1 was able to regulate ITGA5 expression via interacting with miR-1224-5p. CircRSU1 could alleviate LPS-induced HPMEC injury by miR-1224-5p/ITGA5 axis, indicating the potential molecular contribution of circRSU1 in sepsis-ALI.

Phentolamine Protects against Apoptosis and Inflammation in a Neonatal Pneumonia Cell Model Induced by LPS by Regulating the TrkA/Akt Signaling Pathways.

Phentolamine is an α-adrenergic receptor blocker that can be used to treat neonatal pneumonia, but its underlying mechanism is unclear. The purpose of this study is to probe the function of phentolamine on lipopolysaccharide (LPS)-induced inflammation and cell death in an in vitro model of neonatal pneumonia. Human MRC-5 cells were incubated with varying doses of phentolamine in vitro to evaluate cell viability. Subsequently, LPS was introduced to further investigate the combined effects of phentolamine and LPS on cell viability and apoptosis in MRC-5 cells. The effect of phentolamine/LPS treatment on the Neurotrophic Tyrosine Kinase Receptor A (TrkA)/Protein Kinase B (Akt) signaling pathway and the phosphorylation of pathway proteins in MRC-5 cells was further analyzed via western blot. Additionally, knockout of TrkA and Akt genes in MRC-5 cells was performed to explore the effects of phentolamine/LPS treatment on cell viability, apoptosis levels, and inflammatory factor levels in MRC-5 cells. Preincubation of MRC-5 cells with a low concentration of phentolamine (≤6 μg/mL) protected against LPS-induced cell inflammatory injury. Phentolamine promoted both TrkA and Akt phosphorylation and Akt activation induced by LPS in MRC-5 cells. The protective effect of phentolamine against LPS-induced apoptosis and inflammation was significantly reduced in response to TrkA or Akt gene knockdown in MRC-5 cells. Phentolamine may protect LPS-induced apoptosis and inflammation by activating the TrkA and Akt signaling pathways.

Molecular Mechanism of SOX18 in Lipopolysaccharide-Induced Injury of Human Umbilical Vein Endothelial Cells.

Endothelial dysfunction is associated with the progression of sepsis. This study sought to probe the molecular route of sex-determining region on the Y chromosome-box transcription factor 18 (SOX18) in sepsis-associated endothelial injury. Human umbilical vein endothelial cells (HUVECs) were treated with lipopolysaccharide (LPS) to establish the sepsis cell model. Cell viability, lactate dehydrogenase (LDH) release, oxidative stress (reactive oxygen species/malondialdehyde/superoxide dismutase), and inflammation (interleukin-1β/tumor necrosis factor-α/interleukin-6) were evaluated by cell counting kit-8 assay and relevant assay kits. The expression levels of SOX18, microRNA (miR)-204-5p, and cadherin-2 (CDH2) in cells were determined by real-time quantitative polymerase chain reaction and Western blot assay. The interaction of SOX18, miR-204-5p, and CDH2 was analyzed by chromatin immunoprecipitation and dual-luciferase assay. LPS induced HUVECs injury and downregulation of SOX18. SOX18 overexpression increased cell viability, while decreased LDH activity, oxidative stress, and inflammation. SOX18 bound to the miR-204-5p promoter to promote miR-204-5p expression, and further repressed CDH2 expression. miR-204-5p knockdown and CDH2 overexpression abrogated the protective role of SOX18 in HUVECs injury. Overall, SOX18 alleviated LPS-induced injury of HUVECs by promoting miR-204-5p and repressing CDH2, suggesting it as a potential target for sepsis treatment.

Fatty Acid Binding Protein-4 Silencing Inhibits Ferroptosis to Alleviate Lipopolysaccharide-induced Injury of Renal Tubular Epithelial Cells by Blocking Janus Kinase 2/Signal Transducer and Activator of Transcription 3 Signaling.

Sepsis-induced kidney injury (SAKI) has been frequently established as a prevailing complication of sepsis which is linked to unfavorable outcomes. Fatty acid-binding protein-4 (FABP4) has been proposed as a possible target for the treatment of SAKI. In the current work, we aimed to explore the role and underlying mechanism of FABP4 in lipopolysaccharide (LPS)-induced human renal tubular epithelial cell damage. In LPS-induced human kidney 2 (HK2) cells, FABP4 expression was tested by the reverse transcription-quantitative polymerase chain reaction and Western blot. Cell counting kit-8 method assayed cell viability. Inflammatory levels were detected using the enzyme-linked immunosorbent assay. Immunofluorescence staining measured the nuclear translocation of nuclear factor kappa B p65. Thiobarbituric acid-reactive substances assay and C11 BODIPY 581/591 probe were used to estimate the level of cellular lipid peroxidation. Fe2+ content was examined by the kit. In addition, the expression of proteins related to inflammation-, ferroptosis- and Janus kinase 2 (JAK2)/signal transducer, and activator of transcription 3 (STAT3) signaling was detected by the Western blot analysis. The results revealed that FABP4 was significantly upregulated in LPS-treated HK2 cells, the knockdown of which elevated the viability, whereas alleviated the inflammation and ferroptosis in HK2 cells challenged with LPS. In addition, down-regulation of FABP4 inactivated JAK2/STAT3 signaling. JAK2/STAT3 stimulator (colivelin) and ferroptosis activator (Erastin) partially restored the effects of FABP4 interference on LPS-triggered inflammation and ferroptosis in HK2 cells. Together, FABP4 knockdown inhibited ferroptosis to alleviate LPS-induced injury of renal tubular epithelial cells through suppressing JAK2/STAT3 signaling.

SP1-stimulated miR-208a-5p aggravates sepsis-induced myocardial injury via targeting XIAP

The development of sepsis can lead to many organ dysfunction and even death. Myocardial injury is one of the serious complications of sepsis leading to death. New evidence suggests that microRNAs (miRNAs) play a critical role in infection myocardial injury. However, the mechanism which miR-208a-5p regulates sepsis-induced myocardial injury remains unclear. To mimic sepsis-induced myocardial injury in vitro, rat primary cardiomyocytes were treated with LPS. Cell viability and apoptosis were tested by CCK-8 and flow cytometry, respectively. The secretion of inflammatory factors was analyzed by ELISA. mRNA and protein levels were detected by RT-qPCR and Western blotting. The interaction among SP1, XIAP and miR-208a-5p was detected using dual luciferase report assay. Ultrasonic analysis and HE staining was performed to observe the effect of miR-208a-5p in sepsis-induced rats. Our findings indicated that miR-208a-5p expression in primary rat cardiomyocytes was increased by LPS. MiR-208a-5p inhibitor reversed LPS-induced cardiomyocytes injury through inhibiting the apoptosis. Furthermore, the inflammatory injury in cardiomyocytes was induced by LPS, which was rescued by miR-208a-5p inhibitor. In addition, downregulation of miR-208a-5p improved LPS-induced sepsis myocardial injury in vivo. Mechanistically, XIAP might be a target gene of miR-208a-5p. SP1 promoted transcription of miR-208a by binding to the miR-208a promoter region. Moreover, silencing of XIAP reversed the regulatory of miR-208a-5p inhibitor on cardiomyocytes injury. To sum up, those findings revealed silencing of miR-208a-5p could alleviate sepsis-induced myocardial injury, which would grant a new process for the treatment of sepsis.

Astilbin protects from sepsis-induced cardiac injury through the NRF2/HO-1 and TLR4/NF-κB pathway.

Cardiac dysfunction and arrhythmia are severe complications of sepsis-induced cardiomyopathy and are associated with an increased risk of morbidity and mortality. Currently, the precise mechanism for sepsis-induced myocardial damage remains unclear. Astilbin, a flavonoid, is reported to have anti-inflammatory, antioxidative, and antiapoptotic properties. However, the effects of astilbin on sepsis-induced cardiomyopathy have not been studied so far. This study aims to investigate the effect of astilbin in sepsis-induced myocardial injury and elucidate the underlying mechanism. In vivo and in vitro sepsis models were created using lipopolysaccharide (LPS) as an inducer in H9C2 cardiomyocytes and C57BL/6 mice, respectively. Our results demonstrated that astilbin reduced myocardial injury and improved cardiac function. Moreover, astilbin prolonged the QT and corrected QT intervals, attenuated myocardial electrical remodeling, and promoted gap junction protein (Cx43) and ion channels expression, thereby reducing the susceptibility of ventricular fibrillation. In addition, astilbin alleviated LPS-induced inflammation, oxidative stress, and apoptosis. Astilbin suppressed the toll-like receptor 4 (TLR4)/nuclear factor-κB (NF-κB) pathway in vivo and in vitro models. Astilbin remarkedly upregulated the nuclear factor erythroid 2-related factor 2 (NRF2) and heme oxygenase 1 (HO-1) expression. The in vitro treatment with an NRF2 inhibitor reversed the inhibition of the TLR4/NF-κB pathway and antioxidant properties of astilbin. Astilbin attenuated LPS-induced myocardial injury, cardiac dysfunction, susceptibility to VF, inflammation, oxidative stress, and apoptosis by activating the NRF2/HO-1 pathway and inhibiting TLR4/ NF-κB pathway. These results suggest that astilbin could be an effective and promising therapeutics target for the treatment of sepsis-induced cardiomyopathy.

Ferroptosis mediates airway epithelial E-cadherin dysfunction in LPS-induced acute lung injury

BackgroundLoss of E-cadherin in the airway epithelial cells is a critical contributor to the development of ALI/ARDS. Yet the underlying mechanisms are largely unknown. Increasing evidences have revealed the significance of ferroptosis in the pathophysiological process of ALI/ARDS. The aim of this study was to investigate the role of ferroptosis in dysregulation of airway epithelial E-cadherin in ALI/ARDS. MethodsBALB/c mice were subjected to intratracheal instillation of lipopolysaccharide (LPS) to establish an ALI model. Two inhibitors of ferroptosis, liproxstatin-1 (Lip-1, at the dose of 10 mg/kg and 30 mg/kg) and ferrostatin-1 (Fer-1, at the dose of 1 mg/kg and 5 mg/kg), were respectively given to the mice through intraperitoneal injection after LPS challenge. The expression of ferroptotic markers, full-length E-cadherin and soluble E-cadherin (sE-cadherin) were both detected. ResultsLPS exposure dramatically down-regulated pulmonary expression of E-cadherin in mice, with profound loss of membrane E-cadherin in the airway epithelial cells and increased secretion of sE-cadherin in the airway lumen. At the same time, we found that the mitochondrial of airway epithelial cells in LPS-exposed mice exhibited significant morphological alterations that are hallmark features of ferroptosis, with smaller volume and increased membrane density. Other makers of ferroptosis were also detected, including increased cytoplasmic levels of iron and lipid peroxidates (MDA), as well as decreased GPX4 expression. 30 mg/kg of Lip-1 not only showed potent protective effects against the LPS-induced injury, inflammation, edema of the lung in those mice, but also rescued airway epithelial E-cadherin expression and decreased the release of sE-cadherin through inhibiting ferroptosis. While no noticeable changes induced by LPS were observed in mice treated with Lip-1 at 10 mg/kg nor Fer-1 at 1 mg/kg or 5 mg/kg. ConclusionsTaken together, these data demonstrated that ferroptosis mediates airway epithelial E-cadherin dysfunction in LPS-induced ALI.

Acetyl-11-Keto-β-Boswellic Acid Accelerates the Repair of Spinal Cord Injury in Rats by Resisting Neuronal Pyroptosis with Nrf2.

The primary aim of this study is to delve into the potential of Acetyl-11-keto-β-boswellic acid (AKBA) in ameliorating neuronal damage induced by acute spinal cord injury, as well as to unravel the intricate underlying mechanisms. A cohort of 40 Sprague-Dawley rats was meticulously categorized into four groups. Following a seven-day oral administration of AKBA, damaged spinal cord samples were meticulously procured for Nissl staining and electron microscopy to assess neuronal demise. Employing ELISA, immunofluorescence, Western blot (WB), and quantitative polymerase chain reaction (qPCR), the modulatory effects of AKBA within the context of spinal cord injury were comprehensively evaluated. Furthermore, employing an ex vivo extraction of spinal cord neurons, an ATP + LPS-induced pyroptotic injury model was established. The model was subsequently subjected to Nrf2 inhibition, followed by a battery of assessments involving ELISA, DCFH-DA staining, flow cytometry, immunofluorescence, and WB to decipher the effects of AKBA on the spinal cord neuron pyroptosis model. By engaging the Nrf2-ROS-NLRP3 pathway, AKBA exerted a repressive influence on the expression of the pyroptotic initiator protein Caspase-1, thereby mitigating the release of GSDMD and alleviating pyroptosis. Additionally, AKBA demonstrated the ability to attenuate the release of IL-18 and IL-1β, curbing neuronal loss and expediting the restorative processes within the context of spinal cord injury. Our study elucidates that AKBA can reduce spinal cord neuronal apoptosis, providing a basis for the development of AKBA as a clinical treatment for spinal cord injury.