rmMANF prevents sepsis-associated lung injury via inhibiting endoplasmic reticulum stress-induced ferroptosis in mice

Repressing cytokine storm-like response in macrophages by targeting the eIF2α-integrated stress response pathway

Cytokine storm is a life-threatening systemic hyper-inflammatory state caused by different etiologies, in which the bulk production of pro-inflammatory cytokines from activated macrophages has a central role. Integrated stress response (ISR) comprises several protective signaling pathways, leading to phosphorylation of eukaryotic initiation factor 2α (eIF2α) and repression of protein translation. Emerging evidence suggests that ISR induction may elicit anti-inflammatory effects. Currently, however, it is unclear whether targeting eIF2α phosphorylation is sufficient to inhibit the cytokine storm-like response in macrophages. Here we carried out a proof-of-concept study, employing two approaches: (1) ectopic expression of the eIF2α-S51D mutant (mimicking the phosphorylated eIF2α); (2) treatment with salubrinal, a small molecule inhibitor of eIF2α dephosphorylation. Experiments were performed in lipopolysaccharides (LPS)-stimulated macrophages and in murine models with LPS-induced acute endotoxemia. We demonstrated that in macrophages, ectopic expression of eIF2α-S51D, treatment with salubrinal, and gene silencing of PP1/GADD34 (the phosphatase holoenzyme mediating eIF2α dephosphorylation) significantly inhibited LPS-induced cytokine productions without changing their mRNA levels. Polysome PCR and puromycin incorporation assays confirmed that salubrinal suppressed de novo protein translation of the cytokines. In vivo, salubrinal pre-treatment mitigated LPS-induced acute lung injury and significantly reduced the concentration of circulating TNF-α. Salubrinal did not exhibit any effects on the Toll-like receptor 4-mediated signaling or the activation of mammalian target of rapamycin (mTOR). Our data suggest that direct manipulation of eIF2α phosphorylation, thereby bypassing all associated upstream signaling events, may suppress the cytokine storm-like response in activated macrophages, likely by decoupling the gene transcription and protein translation. Inhibiting eIF2α dephosphorylation with small molecule inhibitors may be a viable therapeutic strategy to treat disorders involving cytokine storm-like responses.

Targeting ferroptosis offers therapy choice in sepsis-associated acute lung injury

Sepsis-associated acute lung injury (SALI) is a common complication of sepsis, consisting of a dysfunctional host response to infection-mediated heterogenous complexes. SALI is reported in up to 50 % of patients with sepsis and causes poor outcomes. Despite high incidence, there is a lack of understanding in its pathogenesis and optimal treatment. A better understanding of the molecular mechanisms underlying SALI may help produce better therapeutics. The effects of altered cell-death mechanisms, such as non-apoptotic regulated cell death (RCD) (i.e., ferroptosis), on the development of SALI are beginning to be discovered, while targeting ferroptosis as a meaningful target in SALI is increasingly being recognized. Here, we outline how a susceptible lung alveoli may develop SALI. Then we discuss the general mechanisms underlying ferroptosis, and how it contributes to SALI. We then outline the chemical structures of the emerging agents or compounds that can protect against SALI by inhibiting ferroptosis, summarizing their potential pharmacological effects. Finally, we highlight key limitations and possible strategies to overcome them. This review suggests that a detailed mechanistic and biological understanding of ferroptosis can foster the development of pharmacological antagonists in the treatment of SALI.

Endoplasmic Reticulum Stress Promotes Neuronal Damage in Neonatal Hypoxic-Ischemic Brain Damage by Inducing Ferroptosis

Hypoxic-ischemic brain damage (HIBD) poses a significant risk of neurological damage in newborns. This study investigates the impact of endoplasmic reticulum stress (ERS) on neuronal damage in neonatal HIBD and its underlying mechanisms. HIBD neonatal rat model was constructed and pre-treated with 4-phenylbutiric acid (4-PBA). Nissl and TUNEL staining were utilised to assess neuronal damage and apoptosis in rat brains. HIBD cell model was established by inducing oxygen-glucose deprivation (OGD) in rat H19-7 neurons, which were then pre-treated with Thapsigargin (TG), Ferrostatin-1 (Fer-1), or both. Cell viability and apoptosis of H19-7 neurons were analysed using cell counting kit-8 assay and TUNEL staining. GRP78-PERK-CHOP pathway activity and glutathione peroxidase-4 (GPX4) expression in rat brains and H19-7 neurons were assessed using Western blot. Ferroptosis-related indicators, including glutathione (GSH), superoxide dismutase (SOD), malondialdehyde (MDA) and iron content, were measured using commercial kits in both rat brains and H19-7 neurons. GRP78-PERK-CHOP pathway was overactivated in HIBD neonatal rats' brains, which was mitigated by 4-PBA treatment. 4-PBA treatment demonstrated a reduction in neuronal damage and apoptosis in HIBD-affected neonatal rat brains. Furthermore, it attenuated ferroptosis in rats by increasing GPX4, GSH and SOD while decreasing MDA and iron content. In the OGD-induced H19-7 neurons, Fer-1 treatment counteracted the suppressive effects of TG on viability, the exacerbation of apoptosis, the promotion of ferroptosis and the activation of the GRP78-PERK-CHOP pathway. Overall, ERS facilitates neuronal damage in neonatal HIBD by inducing ferroptosis. Consequently, the suppression of ERS may represent a promising therapeutic strategy for treating neonatal HIBD.

CHAC1 Mediates Endoplasmic Reticulum Stress-Dependent Ferroptosis in Calcium Oxalate Kidney Stone Formation

The initiation of calcium oxalate (CaOx) kidney stone formation is highly likely to stem from injury to the renal tubular epithelial cells (RTECs) induced by stimulation from an aberrant urinary environment. CHAC1 plays a critical role in stress response mechanisms by regulating glutathione metabolism. Endoplasmic reticulum (ER) stress and ferroptosis are demonstrated to be involved in stone formation. This study attempted to elucidate the mechanism of ER stress-dependent ferroptosis and the role of CHAC1 in CaOx kidney stones. Here, regulating ER stress and CHAC1 expression are performed in in vivo and in vitro stone models. These findings indicated that 4-Phenylbutyric acid (4-PBA)treatment and CHAC1 deficiency alleviated the ferroptotic status, including restoring GSH content, suppressing Fe2+ and lipid peroxidation accumulation, as well as regulating ferroptosis-related proteins. Notably, 4-PBA treatment and CHAC1 deficiency both attenuated oxidative damage, improved renal function, importantly, decreased crystal deposition. Additionally, ChIP-seq and ChIP-qPCR analyses demonstrated that CHAC1 is the vital downstream target gene of ATF4. The results indicated that ATF4 depletion inhibited the upregulation of CHAC1 and pro-ferroptotic response induced by Ox stimulation. Overall, ATF4/CHAC1 axis mediating ER stress-dependent ferroptosis may be a promising research direction for identifying potential strategy to prevent and treat CaOx kidney stones.

Protective Effect of Rosmarinic Acid on Endotoxin-Induced Neuronal Damage Through Modulating GRP78/PERK/MANF Pathway

Objective

Neuronal damage is criminal to cognitive dysfunction, closely related to endoplasmic reticulum stress (ERS). However, due to the pathogenesis of endotoxin-induced long-term cognitive dysfunction is not fully clarified, there is still a lack of effective treatment. This study was conducted to explore the protective effects and mechanism of rosmarinic acid (RA) against ERS in endotoxin-induced cognitive dysfunction in mice and neuronal injury in cells.

Methods

The efficacy of RA was evaluated using an endotoxin-induced cognitive dysfunction mice model and an in vitro neuronal injury model. Brain injury was assessed using behavioral tests and hematoxylin and eosin (HE) staining. Western blotting and Immunohistochemistry (IHC) were performed to determine NeuN, GRP78, PERK, ATF6, IRE1α, and MANF expression levels. Molecular docking was used to assess the associated mechanisms.

Results

Behavioral tests indicated that 20 and 40 mg/kg RA significantly improve endotoxin-induced cognitive dysfunction without dose differences. Histological analysis revealed no significant alterations in the number, morphology, and arrangement of neurons in the hippocampus and amygdala. However, 40 mg/kg RA treatment significantly decreased the hippocampal level of PERK protein and increased MANF in CA1 and DG in mice. Furthermore, our data showed that 120 μM RA pretreatment significantly inhibited LPS-conditioned culture-induced GRP78, PERK, and MANF upregulation in vitro. Finally, molecular docking studies suggested that RA could directly interact with GRP78, PERK, and IRE1, but not with MANF.

Conclusion

RA plays a protective role in improving cognitive function against endotoxemia-associated encephalopathy in mice via inhibiting the GRP78/PERK/MANF pathway.

The Protective Effects of Annexin A1 in Acute Lung Injury Mediated by Nrf2

BACKGROUND

Acute lung injury (ALI), one of the most severe respiratory system diseases, is prevalent worldwide. Annexin A1 (AnxA1) is an important member of the annexin superfamily, known for its wide range of physiological functions. However, its potential protective effect against lipopolysaccharide (LPS)-induced ALI remains unclear.

MATERIALS AND METHODS

Mice were divided into four groups: Sham, LPS + vehicle, LPS + 0.1 μg AnxA1, and LPS + 0.5 μg AnxA1. Lung injury was assessed through histopathology, pulmonary wet-to-dry (W/D) ratio, cell counting of bronchoalveolar lavage fluid (BALF), oxidative stress analysis, and noninvasive pulmonary function testing. Gene and protein expression levels were measured using RT-PCR, ELISA, and western blot analysis.

RESULTS

AnxA1 alleviated LPS-induced ALI by protecting lung tissue from damage, reducing the lung wet/dry (W/D) weight ratio, and improving LPS-induced impaired lung function. Interestingly, administration of AnxA1 was found to repress the infiltration of inflammatory cells by decreasing the total cell count, neutrophils, and protein concentrations in bronchoalveolar lavage fluid (BALF). AnxA1 mitigated the inflammatory response in the pulmonary tissue by lowering the levels of IL-1β, IL-6, and TNF-α in BALF of ALI mice. Additionally, AnxA1 attenuated oxidative stress in lung tissues of ALI mice by restoring the activity of catalase (CAT), SOD, and glutathione (GSH) but reducing the levels of malondialdehyde (MDA). We also found that AnxA1 suppressed activation of the NLRP3 signaling pathway. Mechanistically, AnxA1 activated the Nrf2/HO-1 signaling pathway while preventing the activation of NF-κB.

CONCLUSION

Collectively, these findings suggest that AnxA1 alleviates LPS-induced ALI and might be a promising novel therapeutic agent against LPS-induced ALI.

Fibroblast growth factor 21 attenuates pulmonary ischemia/reperfusion injury via inhibiting endoplasmic reticulum stress-induced ferroptosis though FGFR1/PPARδ signaling pathway

BACKGROUND

Acute lung injury is a critical life-threatening complication of pulmonary and cardiac surgery with a high rate of morbidity and mortality. Fibroblast growth factor 21 (FGF21) has been reported to play an important role in protecting vital organs from damage. This study aims to investigate the potential protective role and mechanism of FGF21 in pulmonary ischemia/reperfusion (I/R)-induced acute lung injury.

METHODS

A pulmonary epithelial cell line was treated with hypoxia/regeneration (H/R) in vitro and a mouse model of acute lung injury was induced with pulmonary I/R in vivo. Lung injury after pulmonary I/R was compared between FGF21-konckout (KO) mice and wild-type (WT) mice. Recombinant FGF21 was administrated in vivo and in vitro to determine its therapeutic effect.

RESULTS

Circulating levels of FGF21 in mice with pulmonary I/R injury were significantly higher than in those without pulmonary I/R injury. Lung injury was aggravated in FGF21-KO mice compared with WT mice and the administration of FGF21 alleviated lung injury in mouse treated with I/R and pulmonary epithelial cell injury treated with H/R. FGF21 treatment decreased endoplasmic reticulum (ER) stress, Fe2+ and lipid reactive oxygen species (ROS) contents and GPX4 expression and increased PTGS2 levels. Mechanistically, FGF21 upregulated the expression of FGFR1 and PPARδ, ameliorated ER stress and ER stress induced-ferroptosis. Furthermore, FGF21 increased the expression level of PPARδ in pulmonary epithelial cell exposed to H/R, which was inhibited by FGFR1 inhibitor (PD173074). The protective effects of FGF21 were abolished by co-treatment with PPARδ inhibitor (GSK0660), indicating FGF21 attenuated ER stress-induced ferroptosis by dependent on FGFR1/PPARδ signaling pathway.

CONCLUSION

Our study reveals that FGF21 protects against pulmonary I/R injury via inhibiting ER stress-induced ferroptosis though FGFR1/PPARδ signaling pathway. Boosting endogenous FGF21 or the administration of recombinant FGF21 could be promising therapeutic strategies for pulmonary IRI.

Ferroptosisand Its Role in the Treatment of Sepsis-Related Organ Injury: Mechanisms and Potential Therapeutic Approaches

Sepsis is a complicated clinical disease caused by a defective host response to infection, leading to elevated morbidity and fatality globally. Sepsis patients have a significant risk of life-threatening organ damage, including hearts, brains, lungs, kidneys, and livers. Nevertheless, the molecular pathways driving organ injury in sepsis are not well known. Ferroptosis, a non-apoptotic cell death, occurs due to iron metabolism disturbance and lipid peroxide buildup. Multiple studies indicate that ferroptosis has a significant role in decreasing inflammation and lipid peroxidation during sepsis. Ferroptosis inhibitors and medications, aimed at the most studied ferroptosis process, including Xc-system, Nrf2/GPX4 axis, and NCOA4-FTH1-mediated ferritinophagy, alleviating sepsis effectively. However, few clinical trials demonstrated ferroptosis-targeted drugs's effectiveness in sepsis. Our study examines ferroptosis-targeted medicinal agents and their potential benefits for treating sepsis-associated organ impairment. This review indicates that ferroptosis suppression by pharmaceutical means may be a useful therapy for sepsis-associated organ injury.

Ginsenoside Rg1 improves cigarette smoke-induced ferroptosis in COPD by regulating PERK/ATF4 axis to inhibit endoplasmic reticulum stress

BACKGROUND

Ferroptosis plays a key role in the development of chronic obstructive pulmonary disease (COPD). Whether ginsenoside Rg1 improves cigarette smoke-induced COPD or whether ginsenoside Rg1 improves COPD by inhibiting ferroptosis remains unknown.

METHODS

BEAS-2B cells were exposed to cigarette solution (CSE) for 24 h and treated with ginsenoside Rg1, the ferroptosis inhibitor Fer-1, and the PERK inhibitor GSK. Cell viability, endoplasmic reticulum stress, mitochondrial morphology, membrane potential, reactive oxygen species (ROS), iron levels, and the expression of related proteins were detected using corresponding methods. A COPD mouse model was constructed using cigarette smoke (CS). Ginsenoside Rg1 and GSK were administered via tube feeding 15 days after successful modeling. Mouse lung tissues were evaluated by HE staining. The expression of inflammatory markers, ROS, iron content, and related proteins was detected using corresponding methods.

RESULTS

The results demonstrated that in the CSE-exposed BEAS-2B cell model and CS-induced mouse COPD model, the expression levels of endoplasmic reticulum stress (ERS)-related factors such as GRP78 were increased, while those of the antioxidant markers GPX4 and GSH were significantly decreased. Ginsenoside Rg1 improved emphysema and inflammation by inhibiting ferroptosis in vivo and in vitro. Using a PERK inhibitor, we found that ginsenoside Rg1 inhibited ferroptosis in vivo and in vitro by regulating ERS.

CONCLUSION

This study showed that ginsenoside Rg1 alleviates cigarette smoke-induced COPD by regulating the PERK/ATF4 axis to inhibit ERS and ferroptosis.

Endoplasmic reticulum stress in acute lung injury and pulmonary fibrosis

Pulmonary fibrosis (PF) is a progressive and irreversible lung disease that leads to diminished lung function, respiratory failure, and ultimately death and typically has a poor prognosis, with an average survival time of 2 to 5 years. Related articles suggested that endoplasmic reticulum (ER) stress played a critical role in the occurrence and progression of PF. The ER is responsible for maintaining protein homeostasis. However, factors such as aging, hypoxia, oxidative stress, or inflammation can disrupt this balance, promoting the accumulation of misfolded proteins in the ER and triggering ER stress. To cope with this situation, cells activate the unfolded protein response (UPR). Since acute lung injury (ALI) is one of the key onset events of PF, in this review, we will discuss the role of ER stress in ALI and PF by activating multiple signaling pathways and molecular mechanisms that affect the function and behavior of different cell types, with a focus on epithelial cells, fibroblasts, and macrophages. Linking ER stress to these cell types may broaden our understanding of the mechanisms underlying lung fibrosis and help us target these cells through these mechanisms. The relationship between ER stress and PF is still evolving, and future research will explore new strategies to regulate UPR pathways, providing novel therapeutic targets.

Neohesperidin Dihydrochalcone Alleviates Lipopolysaccharide-Induced Vascular Endothelium Dysfunction by Regulating Antioxidant Capacity

BACKGROUND

Endothelial dysfunction is one of the important mechanisms of organ and tissue damage in sepsis. In this study, we evaluated the effects of neohesperidin dihydrochalone (NHDC) on lipopolysaccharide (LPS)-induced vascular dysfunction and explored the potential mechanisms.

METHODS

In vivo, we assessed vascular leakage in mice by injecting Evans blue dye. In vitro, cell counting kit-8 (CCK-8) assay and flow cytometry were used to assess the activity of HUVEC and apoptosis. The effect of LPS on HUVEC barrier was assessed using FITC-extend membrane assay. The adhesion ability of HUVEC was tested by THP-1 cell adhesion assay. The antioxidant capacity of cells was measured by detecting the level of mitochondrial membrane potential, ROS, and content of CAT, SOD, GSH, and MDA within the cells. Furthermore, the release of endothelial IL-1β, IL-6, and TNF-α were detected by ELISA, and the expression level of TAK1, ERK1/2, and NFκB were detected by western blot.

RESULTS

Treatment with NHDC effectively alleviated LPS-induced endothelial permeability and organ damage by reducing reactive oxygen species production and enhancing the antioxidant response. Further investigation suggested that NHDC may exert its protective effects by inhibiting the release of IL-1β, IL-6, and TNF-α, and by decreasing the phosphorylation of key inflammatory signaling molecules, including transforming growth factor-β-activated kinase 1 (TAK1), extracellular signal-regulated kinases 1/2 (ERK1/2), and nuclear factor kappa B (NFκB).

CONCLUSIONS

Our study indicate that pretreatment with NHDC may provide protection against LPS-induced vascular dysfunction by reducing oxidative stress and activation of inflammatory signaling pathways.

MANF inhibits NLRP3 inflammasome activation by competitively binding to DDX3X in paraquat-stimulated alveolar macrophages

NLRP3 inflammasome activation in macrophages is involved in paraquat-induced acute lung injury (ALI). MANF exerts an inhibitory effect against inflammation and cell death. The aim of this study was to investigate the role of MANF in paraquat-stimulated alveolar macrophages and the potential mechanism. Paraquat-induced ALI mouse model was established by intraperitoneally injection of 30 mg/kg of paraquat. The lung pathological changes were observed by hematoxylin and eosin staining. The expression of MANF/DDX3X/NLRP3/Caspase-1 in mice lung macrophages was evaluated by double immunofluorescence staining and western blot. NLRP3 inflammasome activation and pro-inflammatory cytokines (IL-1β and IL-18) in paraquat-stimulated macrophage transfected with MANF overexpression plasmid (pcDNA3.1-MANF) or siRNA-MANF were measured by Western blot. The protein-protein interaction of MANF/DDX3X/NLRP3 was verified by Co-immunoprecipitation. As a result, MANF/DDX3X/NLRP3/Caspase-1 were upregulated in alveolar macrophages of paraquat-induced ALI in mice. In paraquat-stimulated alveolar macrophages, upregulation of MANF and DDX3X were also observed, accompanied by NLRP3 inflammasome activation. In addition, overexpression of MANF inhibited NLRP3 inflammasome activation in paraquat-stimulated alveolar macrophages. In contrast, knockdown of MANF aggravated NLRP3 inflammasome activation. Co-immunoprecipitation results revealed that DDX3X could bind to MANF and NLRP3, but MANF could not bind to NLRP3 in paraquat-stimulated alveolar macrophages. Furthermore, Co-immunoprecipitation of truncated three fragments of DDX3X confirmed MANF can interact with the helicase core of DDX3X which is the binding site for NLRP3. Taken together, MANF exerted a protective effect against paraquat-induced cytotoxicity by inhibiting the NLRP3 inflammasome activation in macrophages via competitive binding to the helicase core of DDX3X.

Association of coexposure to perfluoroalkyl and polyfluoroalkyl compounds and heavy metals with pregnancy loss and reproductive lifespan: The mediating role of cholesterol

Previous studies have demonstrated the toxic effects of per- and polyfluoroalkyl substances (PFASs) and heavy metals on the reproductive system. However, the interactions and combined effects of these substances remain unexplored. This study utilizes data from the National Health and Nutrition Examination Survey to investigate the associations between coexposure to four types of PFASs, lead (Pb), mercury (Hg) and self-reported pregnancy loss and reproductive lifespan in females. Genes associated with these substances and abortion were identified via the Comparative Toxicogenomics Database. The results revealed that Ln-PFOA (IRR=1.88, 95 % CI=1.42-2.50, Ln--: log transformed), Ln-PFOS (IRR=1.58, 95 % CI=1.12-2.22), Ln-PFHxS (IRR=1.99, 95 % CI=1.57-2.52), and Ln-Hg (IRR=1.92, 95 % CI=1.41-2.43) were positively associated with the risk of pregnancy loss. Ln-PFOA (β=1.27, 95 % CI=0.28-2.27), Ln-PFOS (β=1.01, 95 % CI=0.39-1.63), Ln-PFHxS (β=0.71, 95 % CI=0.12-1.63), Ln-PFNA (β=1.15, 95 % CI=0.23-2.08), Ln-Pb (β=3.87, 95 % CI=2.58-5.15), and Ln-Hg (β=1.01, 95 % CI=0.39-1.64) exposures were positively associated with reproductive lifespan. The mixed and overall effects of coexposure to PFASs and heavy metals were positively correlated with the risk of pregnancy loss and reproductive lifespan. Cholesterol partially mediated the association with the risk of pregnancy loss, whereas delay in menopause fully mediated the association with reproductive lifespan. Significant additive interactions were observed between PFOA and Pb and between PFOS, PFHxS, PFNA and Hg at high levels of coexposure. Thirty-nine overlapping genes associated with abortion were identified for these substances, and further analyses revealed that these genes significantly interact and may contribute to abortion through oxidative stress.

GSK3179106 ameliorates lipopolysaccharide-induced inflammation and acute lung injury by targeting P38 MAPK

Acute lung injury (ALI) is a serious acute respiratory disease that can cause alveolar-capillary barrier disruption and pulmonary edema, respiratory failure and multiple organ dysfunction syndrome. However, there is no effective drugs in clinic until now. GSK3179106 has been reported can alleviate intestinal stress syndrome, but the protective effect of GSK3179106 on ALI has not been elucidated. The present study will evaluate the pharmacological activity of GSK3179106 on lipopolysaccharide (LPS)-induced inflammation and lung injury and clarify its underlying mechanism. We found that GSK3179106 significantly attenuated LPS-induced lung injury in vivo, accompanied by inhibited infiltration of inflammatory cells and reduced expression of inflammatory cytokines. Meanwhile, GSK3179106 dose-dependently reduced the LPS-induced IL-6 expression both in protein and gene levels in macrophages. Mechanistically, GSK3179106 could inhibited the phosphorylation of P38 MAPK induced by LPS. Importantly, results showed that there is a direct combination between GSK3179106 and P38 MAPK. Together, our findings not only clarified the anti-inflammatory activity of GSK3179106 but also discovered its new clinical indications. Therefore, compound GSK3179106 may be a potential candidate for the treatment of acute inflammatory diseases.

Molecular mechanisms of endoplasmic reticulum stress-mediated acute kidney injury in juvenile rats and the protective role of mesencephalic astrocyte-derived neurotrophic factor

OBJECTIVES

This study examined the role of endoplasmic reticulum stress in pediatric acute kidney injury and the therapeutic effect of midbrain astrocyte-derived neurotrophic factor.

METHODS

Two-week-old Sprague-Dawley rats were divided into: Sham, ischemia-reperfusion injury-induced acute kidney injury (AKI), mesencephalic astrocyte-derived neurotrophic factor (MANF)-treated, tauroursodeoxycholic acid (TUDCA)-treated. Analyses were conducted 24 h post-treatment. Serum creatinine, cystatin C, Albumin, MANF levels were measured, cytokine concentrations in serum and renal tissues were determined using a Luminex assay. Histopathology was assessed via light and electron microscopy. Western blotting and RT-qPCR analyzed markers for oxidative stress, apoptosis, endoplasmic reticulum (ER) stress, and autophagy. HK-2 cells underwent hypoxia/reoxygenation (H/R) to simulate AKI and were treated with MANF or TUDCA.

RESULTS

AKI rats had increased serum creatinine, cystatin C, and inflammatory cytokines, along with significant renal damage, and showed loose and swollen ER structures, reduced cell proliferation, and elevated levels of IRE1, PERK, ATF6, CHOP, LC3-II/I, KIM-1, TLR4, JNK, and NF-κB. MANF treatment reduced these biomarkers and protein levels, improved ER structure and cell proliferation, alleviated oxidative stress, apoptosis, ER stress, and inhibited JNK/TLR4/NF-κB signaling. In HK-2 cells, MANF reduced ER stress and inflammation post-H/R exposure.

CONCLUSIONS

MANF treatment alleviates ER stress, oxidative stress, apoptosis, and inflammation in pediatric AKI, improving renal function and morphology.

Focus on the role of calcium signaling in ferroptosis: a potential therapeutic strategy for sepsis-induced acute lung injury

By engaging in redox processes, ferroptosis plays a crucial role in sepsis-induced acute lung injury (ALI). Although iron stimulates calcium signaling through the stimulation of redox-sensitive calcium pathways, the function of calcium signals in the physiological process of ferroptosis in septic ALI remains unidentified. Iron homeostasis disequilibrium in ferroptosis is frequently accompanied by aberrant calcium signaling. Intracellular calcium overflow can be a symptom of dysregulation of the cellular redox state, which is characterized by iron overload during the early phase of ferroptosis. This can lead to disruptions in calcium homeostasis and calcium signaling. The mechanisms controlling iron homeostasis and ferroptosis are reviewed here, along with their significance in sepsis-induced acute lung injury, and the potential role of calcium signaling in these processes is clarified. We propose that the development of septic acute lung injury is a combined process involving the bidirectional interaction between iron homeostasis and calcium signaling. Our goal is to raise awareness about the pathophysiology of sepsis-induced acute lung injury and investigate the relationship between these mechanisms and ferroptosis. We also aimed to develop calcium-antagonistic therapies that target ferroptosis in septic ALI and improve the quality of survival for patients suffering from acute lung injury.

Key subdomains of mesencephalic astrocyte-derived neurotrophic factor attenuate myocardial ischemia/reperfusion injury by JAK1/STAT1/NF-κB signaling pathway

BACKGROUND

Myocardial ischemia/reperfusion (I/R) injury is a common pathological process in clinical practice. Developing effective therapeutic strategies to reduce or prevent this injury is crucial. The article aimed to investigate the role and mechanism of mesencephalic astrocyte-derived neurotrophic factor (MANF) and its key subdomains in modulating myocardial I/R-induced cardiomyocyte apoptosis.

METHODS

MANF stable knockout cell line and MANF mutant overexpression plasmids were constructed. The effects of MANF and mutants on apoptosis and endoplasmic reticulum (ER) stress related proteins were evaluated in hypoxia/reoxygenation-induced HL-1 cardiomyocytes by western blot, immunofluorescence, Tunel and flow cytometry. Echocardiography, ELISA, TTC and Masson were used to observe the effects of recombinant MANF protein (rMANF) on cardiac function in myocardial I/R mice.

RESULTS

This study observed increased expression of MANF in both myocardial infarction patients and I/R mice. MANF overexpression in cardiomyocytes decreased ER stress-induced apoptosis, while MANF knockout exacerbated it. rMANF improved cardiac function in I/R mice by reducing injury and inflammation. This study specifically demonstrates that mutations in the α-helix of MANF were more effective in reducing ER stress and cardiomyocyte apoptosis. Mechanistically, MANF and the α-helix mutant attenuated I/R injury by inhibiting the JAK1/STAT1/NF-κB signaling pathway in addition to reducing ER stress-induced apoptosis.

CONCLUSION

These findings highlight MANF and its subdomains as critical regulators of myocardial I/R injury, offering promising therapeutic targets with significant clinical implications for I/R-related diseases.

Identification of potential biomarkers for sepsis based on neutrophil extracellular trap-related genes

Sepsis is a highly lethal disease that poses a serious threat to human health. Increasing evidence indicates that neutrophil extracellular traps (NETs) are key factors in the pathological progression of sepsis. This study aims to screen potential biomarkers for sepsis and delve into their regulatory function in the pathogenesis. We downloaded 6 microarray datasets from the Gene Expression Omnibus (GEO) database, with 4 as the training sets and 2 as the validation sets. NETs-related genes (NRGs) were obtained from relevant literature. Differential expression analysis was performed on four training sets separately. We intersected differentially expressed genes (DEGs) from the four training sets and NRGs, finally resulting in 19 NETs-related sepsis genes. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) unearthed that NETs-related sepsis genes were majorly abundant in functions and pathways such as defense response to bacterium and Neutrophil extracellular trap formation. Using the PPI network, the MCC algorithm, and the MCODE algorithm in the CytoHubba plugin, 7 sepsis hub genes (ELANE, TLR4, MPO, PADI4, CTSG, MMP9, S100A12) were identified. ROC curve for each Hub gene in the training and validation sets were plotted, which revealed that the Area Under Curve (AUC) values are all greater than 0.6, indicating good classification ability. A total of 349 miRNAs targeting Hub genes were predicted in the mirDIP database, and 620 lncRNAs targeting miRNAs were predicted in the ENCORI database. The ceRNA regulatory network was constructed using Cytoscape software. Finally, we employed the cMAP database to predict small molecular complexes as potentially effective drugs for the treatment of sepsis, such as chloroquine, harpagoside, and PD-123319. In conclusion, this project successfully identified 7 core genes, which may serve as promising candidates for novel sepsis biomarkers. Meanwhile, we constructed a related ceRNA network and predicted potential targeted drugs, providing potential therapeutic targets and treatment strategies for sepsis patients.

Role and mechanisms of autophagy, ferroptosis, and pyroptosis in sepsis-induced acute lung injury

Sepsis-induced acute lung injury (ALI) is a major cause of death among patients with sepsis in intensive care units. By analyzing a model of sepsis-induced ALI using lipopolysaccharide (LPS) and cecal ligation and puncture (CLP), treatment methods and strategies to protect against ALI were discussed, which could provide an experimental basis for the clinical treatment of sepsis-induced ALI. Recent studies have found that an imbalance in autophagy, ferroptosis, and pyroptosis is a key mechanism that triggers sepsis-induced ALI, and regulating these death mechanisms can improve lung injuries caused by LPS or CLP. This article summarized and reviewed the mechanisms and regulatory networks of autophagy, ferroptosis, and pyroptosis and their important roles in the process of LPS/CLP-induced ALI in sepsis, discusses the possible targeted drugs of the above mechanisms and their effects, describes their dilemma and prospects, and provides new perspectives for the future treatment of sepsis-induced ALI.

HMGB1 inhibition blocks ferroptosis and oxidative stress to ameliorate sepsis-induced acute lung injury by activating the Nrf2 pathway

The proinflammatory properties of high-mobility group box protein 1 (HMGB1) in sepsis have been extensively studied. This study aimed to investigate the impact of HMGB1 on ferroptosis and its molecular mechanism in sepsis-induced acute lung injury (ALI). A septic mouse model was established using the cecal ligation and puncture method. Blocking HMGB1 resulted in improved survival rates, reduced lung injury, decreased levels of ferroptosis markers (reactive oxygen species, malondialdehyde, and Fe2+), and enhanced antioxidant enzyme activities (superoxide dismutase and catalase) in septic mice. In addition, knockdown of HMGB1 reduced cellular permeability, ferroptosis markers, and raised antioxidant enzyme levels in lipopolysaccharide (LPS)-stimulated MLE-12 cells. Silencing of HMGB1 led to elevations in the expressions of ferroptosis core-regulators in LPS-treated MLE-12 cells, such as solute carrier family 7 member 11 (SLC7A11), solute carrier family 3 member A2 (SLC3A2), and glutathione peroxidase 4. Furthermore, blocking HMGB1 did not alter ferroptosis, oxidative stress-related changes, and permeability in LPS-treated MLE-12 cells that were pretreated with ferrostatin-1 (a ferroptosis inhibitor). HMGB1 inhibition also led to elevated expressions of nuclear factor erythroid 2-related factor 2 (Nrf2) and its downstream targets, heme oxygenase-1 (HO-1) and NAD(P)H: quinone oxidoreductase 1 (NQO1) in LPS-treated MLE-12 cells and lung tissues from septic mice. The Nrf2-specific inhibitor ML385 reversed the effects of HMGB1 silencing on ferroptosis and cell permeability in LPS-treated MLE-12 cells. Our findings indicated that the inhibition of HMGB1 restrains ferroptosis and oxidative stress, thereby alleviating sepsis-induced ALI through the activation of Nrf2 signaling.

Chemical composition and bioactivity variability of two-step extracts derived from traditional and "QiNan" agarwood (Aquilaria spp.)

One of the primary applications for agarwood lies in the extracts, instead, there are obvious differences in the demands for agarwood components with different application fields. To obtain the rough separation and clarify each part's activity, four extracts of essential oil, hydrolat, extractum, and ethanol precipitation from traditional agarwood (TraA) and "Qinan" agarwood (QinA) were obtained by steam-solvent multistage extraction and ethanol precipitation. We investigated the chemistry and biological activity of multistage extracts using gas chromatography-mass spectrometry (GC-MS), high-performance liquid chromatography (HPLC), and in vitro activity testing. The results demonstrated that two kinds of agarwood essential oils contained mainly sesquiterpenoids, yet the sesquiterpene species were remarkably diverse in two kinds of agarwood essential oils. Then, the TraA and QinA hydrolat, all predominantly aromatic and sesquiterpene, but with differences from the essential oil ingredients. Additionally, the extractum chiefly contained chromones and the ethanol precipitation method worked well to separate the impurities in the TraA extract, however, it was ineffective for the QinA extract. Ultimately, essential oils and extractums all have antioxidant properties, with extractums outperforming essential oils. Moreover, both extractums and essential oils exhibited excellent broad-spectrum antimicrobial activity and anti-inflammatory activity. The findings pointed to the feasibility of separating the primary components from TraA and QinA using a multi-stage extraction technique, providing a scientific basis for the efficient utilization of all components of agarwood, as well as the functional product development and differentiated utilization of extract products in incense, fragrance, perfume, and daily chemicals.

Exploring the effect of Clostridium butyricum on lung injury associated with acute pancreatitis in mice by combined 16S rRNA and metabolomics analysis

OBJECTIVES

Acute lung injury is a critical complication of severe acute pancreatitis (SAP). The gut microbiota and its metabolites play an important role in SAP development and may provide new targets for AP-associated lung injury. Based on the ability to reverse AP injury, we proposed that Clostridium butyricum may reduce the potential for AP-associated lung injury by modulating with intestinal microbiota and related metabolic pathways.

METHODS

An AP disease model was established in mice and treated with C. butyricum. The structure and composition of the intestinal microbiota in mouse feces were analyzed by 16 S rRNA gene sequencing. Non-targeted metabolite analysis was used to quantify the microbiota derivatives. The histopathology of mouse pancreas and lung tissues was examined using hematoxylin-eosin staining. Pancreatic and lung tissues from mice were stained with immunohistochemistry and protein immunoblotting to detect inflammatory factors IL-6, IL-1β, and MCP-1.

RESULTS

C. butyricum ameliorated the dysregulation of microbiota diversity in a model of AP combined with lung injury and affected fatty acid metabolism by lowering triglyceride levels, which were closely related to the alteration in the relative abundance of Erysipelatoclostridium and Akkermansia. In addition, C. butyricum treatment attenuated pathological damage in the pancreatic and lung tissues and significantly suppressed the expression of inflammatory factors in mice.

CONCLUSIONS

C. butyricum may alleviate lung injury associated with AP by interfering with the relevant intestinal microbiota and modulating relevant metabolic pathways.

Rosmarinic acid alleviates septic acute respiratory distress syndrome in mice by suppressing the bronchial epithelial RAS-mediated ferroptosis

Activating angiotensin-converting enzyme 2 (ACE2) is an important player in the pathogenesis of septic-related acute respiratory distress syndrome (ARDS). Rosmarinic acid (RA) as a prominent polyphenolic secondary metabolite derived from Rosmarinus officinalis modulates ACE2 in sepsis remains unclear, although its impact on ACE inhibition and septic-associated lung injury has been explored. The study investigated the ACE2 expression in lipopolysaccharide (LPS)-induced lungs in mice and BEAS2B cells. Additionally, molecular docking, protein-protein interaction (PPI) network analysis, and western blotting were employed to predict and evaluate the molecular mechanism of RA on LPS-induced ferroptosis in vivo and in vitro. LPS-induced glutathione peroxidase 4 (GPX4) downregulation, ACE/ACE2 imbalance, and alteration of frequency of breathing (BPM), minute volume (MV), and the expiratory flow at 50% expired volume (EF50) were reversed by captopril pretreatment in vitro and in vivo. RA notably inhibited the infiltration into the lungs of neutrophils and monocytes with increased amounts of GPX4 and ACE2 proteins, lung function improvement, and decreased inflammatory cytokines levels and ER stress in LPS-induced ARDS in mice. Molecular docking showed RA was able to interact with ACE and ACE2. Moreover, combined with different pharmacological inhibitors to block ACE and ferroptosis, RA still significantly inhibited inflammatory cytokines Interleukin-1ß (IL-1ß), tumor necrosis factor-α (TNF-α), and C-X-C motif chemokine 2 (CXCL2) levels, as well as improved lung function, and enhanced GPX4 expression. Particularly, the anti-ferroptosis effect of RA in LPS-induced septic ARDS is RAS-dependent.

Edaravone dexborneol protects against cerebral ischemia/reperfusion-induced blood-brain barrier damage by inhibiting ferroptosis via activation of nrf-2/HO-1/GPX4 signaling

PURPOSE

Ferroptosis has recently been recognized as a mechanism of cerebral ischemia-reperfusion (I/R) injury, attributed to blood-brain barrier (BBB) disruption. Edaravone dexboneol (Eda.B) is a novel neuroprotective agent widely employed in ischemic stroke, which is composed of edaravone (Eda) and dexborneol. This study aimed to investigate the protective effects of Eda.B on the BBB in cerebral I/R and explore its potential mechanisms.

METHODS

Transient middle cerebral artery occlusion (tMCAO) Sprague-Dawley-rats model was used. Rats were randomly assigned to sham-operated group (sham, n = 20), model group (tMCAO, n = 20), Eda.B group (Eda.B, n = 20), Eda group (Eda, n = 20) and dexborneol group (dexborneol, n = 20), and Eda.B + Zinc protoporphyria group (Eda.B + ZnPP, n = 5). Infarct area, cellular apoptosis and neurofunctional recovery were accessed through TTC staining, TUNEL staining, and modified Garcia scoring system, respectively. BBB integrity was evaluated via Evans blue staining. Nuclear factor E2 related factor 2 (Nrf-2)/heme oxygenase 1 (HO-1)/glutathione peroxidase 4 (GPX4) signaling were qualified by Western blot. Transmission electron microscopy (TEM) revealed alterations in ipsilateral brain tissue among groups. Glutathione (GSH) and malondialdehyde (MDA) levels, and Fe2+ tissue content determination were detected.

RESULTS

Eda.B effectively improved neurological deficits, diminished infarct area and cellular apoptosis, as well as ameliorated BBB integrity in tMCAO rats. Further, Eda.B significantly inhibited ferroptosis, as evidenced by ameliorated pathological features of mitochondria, down-regulated of MDA and Fe2+ levels and up-regulated GSH content. Mechanistically, Eda.B attenuated BBB disruption via Nrf-2-mediated ferroptosis, promoting nuclear translocation of Nrf-2, increasing HO-1, GPX4 expression, alleviating the loss of zonula occludens 1 (ZO-1) and occludin as well as decreasing 4-hydroxynonenal (4-HNE) level.

CONCLUSIONS

This study revealed for the first time that Eda.B safeguarded the BBB from cerebral I/R injury by inhibiting ferroptosis through the activation of the Nrf-2/HO-1/GPX4 axis, providing a novel insight into the neuroprotective effect of Eda.B in cerebral I/R.

ATF4 in cellular stress, ferroptosis, and cancer

Activating transcription factor 4 (ATF4), a member of the ATF/cAMP response element-binding (CREB) family, plays a critical role as a stress-induced transcription factor. It orchestrates cellular responses, particularly in the management of endoplasmic reticulum stress, amino acid deprivation, and oxidative challenges. ATF4's primary function lies in regulating gene expression to ensure cell survival during stressful conditions. However, when considering its involvement in ferroptosis, characterized by severe lipid peroxidation and pronounced endoplasmic reticulum stress, the ATF4 pathway can either inhibit or promote ferroptosis. This intricate relationship underscores the complexity of cellular responses to varying stress levels. Understanding the connections between ATF4, ferroptosis, and endoplasmic reticulum stress holds promise for innovative cancer therapies, especially in addressing apoptosis-resistant cells. In this review, we provide an overview of ATF4, including its structure, modifications, and functions, and delve into its dual role in both ferroptosis and cancer.

Inhibition of CISD1 alleviates mitochondrial dysfunction and ferroptosis in mice with acute lung injury

The NET family member, CDGSH iron-sulfur domain-containing protein 1 (CISD1), is located in theoutermembrane of mitochondria, where it regulates energy and iron metabolism. CISD1 has vital functions in certain human diseases; however, its function in acute lung injury (ALI) is unknown. ALI pathogenesis critically involves mitochondrial dysfunction and ferroptosis, which might be regulated by CISD1. Therefore, we investigated CISD1's function in mitochondrial dysfunction and ferroptosis regulation in lipopolysaccharide (LPS)-induced ALI. We found that CISD1 was upregulated in LPS-induced ALI,and silencing Cisd1 prevented cell apoptosis and increased cell viability. When CISD1was inhibited by mitoNEET ligand-1 (NL-1) there was a significant mitigation of pathological injury and lung edema, and reduced numbers of total cells, polymorphonuclear leukocytes, and a decreased protein content in the bronchoalveolar lavage fluid (BALF). Moreover, inhibition of CISD1 markedly decreased the interleukin (IL)6, IL-1β, and tumor necrosis factor alpha (TNF-α) levels in the lungs and BALF of ALI-model mice. Silencing of Cisd1 prevented LPS-induced mitochondrial membrane potential depolarization, cellular ATP reduction, and reactive oxygen species (ROS) accumulation, suggesting mitochondrial protection. ALI activated ferroptosis, as evidenced by the increased lipid-ROS, intracellular Fe2+ level, reduced Gpx4 (glutathione peroxidase 4) expression, and the glutathione/glutathione disulfide ratio. Interestingly, inhibition of CISD1 reduced LPS-induced ferroptosis in vivo and in vitro. In conclusion, inhibition of CISD1 alleviated mitochondrial dysfunction and ferroptosis in LPS-induced ALI, identifying CISD1 as possible target for therapy of LPS-induced ALI.

Ferroptosis and endoplasmic reticulum stress in ischemic stroke

Ferroptosis is a form of non-apoptotic programmed cell death, and its mechanisms mainly involve the accumulation of lipid peroxides, imbalance in the amino acid antioxidant system, and disordered iron metabolism. The primary organelle responsible for coordinating external challenges and internal cell demands is the endoplasmic reticulum, and the progression of inflammatory diseases can trigger endoplasmic reticulum stress. Evidence has suggested that ferroptosis may share pathways or interact with endoplasmic reticulum stress in many diseases and plays a role in cell survival. Ferroptosis and endoplasmic reticulum stress may occur after ischemic stroke. However, there are few reports on the interactions of ferroptosis and endoplasmic reticulum stress with ischemic stroke. This review summarized the recent research on the relationships between ferroptosis and endoplasmic reticulum stress and ischemic stroke, aiming to provide a reference for developing treatments for ischemic stroke.

Self-Assembled Acid-Responsive Nanosystem for Synergistic Anti-Angiogenic/Photothermal/Ferroptosis Therapy against Esophageal Cancer

Esophageal cancer (EC) treatment via anti-angiogenic therapy faces challenges due to non-cytotoxicity and non-specific biodistribution of the anti-angiogenic agents. Hence, the quest for a synergistic treatment modality and a targeted delivery approach to effectively address EC has become imperative. In this study, an acid-responsive release nanosystem (Bev-IR820@FeIII TA) that involves the conjugation of bevacizumab, an anti-angiogenic monoclonal antibody, with TA and Fe3+ to form a metal-phenolic network, followed by loading with the near-infrared photothermal agent (IR820) to achieve combinational therapy, is designed. The construction of Bev-IR820@FeIII TA can be realized through a facile self-assembly process. The Bev-IR820@FeIII TA exhibits tumor-targeting capabilities and synergistic therapeutic effects, encompassing anti-angiogenic therapy, photothermal therapy (PTT), and ferroptosis therapy (FT). Bev-IR820@FeIII TA exhibits remarkable proficiency in delivering drugs to EC tissue through its pH-responsive release properties. Consequently, bevacizumab exerts its therapeutic effects by obstructing tumor angiogenesis, thereby impeding tumor growth. Meanwhile, PTT facilitates localized thermal ablation at the tumor site, directly eradicating EC cells. FT synergistically collaborates with PTT, giving rise to the formation of a reactive oxygen species (ROS) storm, subsequently culminating in the demise of EC cells. In summary, this amalgamated treatment modality carries substantial promise for synergistically impeding EC progression and showcases auspicious prospects for future EC treatment.

The role of TRPV4 in programmed cell deaths

Programmed cell death is a major life activity of both normal development and disease. Necroptosis is early recognized as a caspase-independent form of programmed cell death followed obviously inflammation. Apoptosis is a gradually recognized mode of cell death that is characterized by a special morphological changes and unique caspase-dependent biological process. Ferroptosis, pyroptosis and autophagy are recently identified non-apoptotic regulated cell death that each has its own characteristics. The transient receptor potential vanilloid 4 (TRPV4) is a kind of nonselective calcium-permeable cation channel, which is received more and more attention in biology studies. It is widely expressed in human tissues and mainly located on the membrane of cells. Several researchers have identified that the influx Ca2+ from TRPV4 acts as a key role in the loss of cells by apoptosis, ferroptosis, necroptosis, pyroptosis and autophagy via mediating endoplasmic reticulum (ER) stress, oxidative stress and inflammation. This effect is bad for the normal function of organs on the one hand, on the other hand, it is benefit for anticancer activities. In this review, we will summarize the current discovery on the role and impact of TRPV4 in these programmed cell death pathological mechanisms to provide a new prospect of gene therapeutic target of related diseases.

DPP2/7 is a Potential Predictor of Prognosis and Target in Immunotherapy in Colorectal Cancer: An Integrative Multi-omics Analysis

BACKGROUND

Colorectal cancer (CRC) ranks among the leading causes of cancerrelated deaths.

OBJECTIVE

This study aimed to illuminate the relationship between DPP7 (also known as DPP2) and CRC through a combination of bioinformatics and experimental methodologies.

METHODS

A multi-dimensional bioinformatic analysis on DPP7 was executed, covering its expression, survival implications, clinical associations, functional roles, immune interactions, and drug sensitivities. Experimental validations involved siRNA-mediated DPP7 knockdown and various cellular assays.

RESULTS

Data from the Cancer Genome Atlas (TCGA) identified high DPP7 expression in solid CRC tumors, with elevated levels adversely affecting patient prognosis. A shift from the N0 to the N2 stage in CRC was associated with increased DPP7 expression. Functional insights indicated the involvement of DPP7 in cancer progression, particularly in extracellular matrix disassembly. Immunological analyses showed its association with immunosuppressive entities, and in vitro experiments in CRC cell lines underscored its oncogenic attributes.

CONCLUSION

DPP7 could serve as a CRC prognosis marker, functioning as an oncogene and representing a potential immunotherapeutic target.

TMEM16A deficiency in alveolar type 2 epithelial cells protected against endoplasmic reticulum stress-induced ferroptosis during acute lung injury

Transmembrane protein 16A (TMEM16A) is one of the members of the ten-member family of "transmembrane protein 16", playing critical roles in infection and solid organ injury. Acute lung injury (ALI) is a devastating disease which could be triggered by sepsis, trauma, and ischemia reperfusion. However, molecular mechanisms contributing to ALI are poorly understood at presently. In this study, we investigated the role of TMEM16A in sepsis-induced ALI using TMEM16A-deficient mice. Sepsis-induced ALI model was established by intratracheal injection of lipopolysaccharide (LPS). Our results showed that LPS stimulation significantly upregulated the expression levels of TMEM16A in lung tissues and in alveolar epithelial type II (AT2) cells. Knockout of TMEM16A in AT2 cells significantly improved pulmonary function and alleviated lung pathological injury in LPS-treated mice. Meanwhile, TMEM16A deficiency also inhibited endoplasmic reticulum (ER) stress and ferroptosis in AT2 cells from LPS-treated mice. In vitro experiments further demonstrated that ER stress and ferroptosis were inhibited after TMEM16A was knocked out. Furthermore, we used ER stress inducer thapsigargin to induce ER stress in TMEM16A-null AT2 cells and found that the induction of ER stress abolished the inhibition of ferroptosis by TMEM16A deficiency in LPS-treated AT2 cells. Finally, we disclosed that pharmacological inhibition of TMEM16A by shikonin also showed similar therapeutic effect on LPS-induced ALI in vivo. In conclusion, TMEM16A deficiency in AT2 cells could alleviate sepsis-induced ALI by decreasing ER stress-induced ferroptosis during ALI.

Predicting the prognosis in patients with sepsis by an endoplasmic reticulum stress gene signature

BACKGROUND

Prognostic stratification of patients with sepsis is important for the development of individualized treatment strategies. Endoplasmic reticulum stress (ERS) plays a key role in sepsis. This study aimed to identify a set of genes related to ER stress to construct a predictive model for the prognosis of sepsis.

METHODS

The transcriptomic and clinical data of 479 sepsis patients were obtained from GSE65682 and divided into a training set (n=288) and a validation set (n=191) at a ratio of 3:2. The external test set was GSE95233 (n=51). LASSO and Cox regression analyses were performed to establish a signature to predict the prognosis of patients with sepsis. Moreover, we developed a nomogram that included the risk signature and clinical features to predict survival probability.

RESULTS

A prognostic signature was constructed with ten endoplasmic reticulum related genes (ADRB2, DHCR7, GABARAPL2, MAOA, MPO, PDZD8, QDPR, SCAP, TFRC, and TLR4) in the training set, which significantly divided patients with sepsis into high- and low-risk groups in terms of survival. This signature was validated using validation and external test sets. A nomogram based on the risk signature was constructed to quantitatively predict the prognosis of patients with sepsis.

CONCLUSIONS

We constructed an ERS signature as a novel prognostic marker for predicting survival in sepsis patients, which could be used to develop novel biomarkers for the diagnosis, treatment, and prognosis of sepsis and to provide new ideas and prospects for future clinical research.

FARSB Facilitates Hepatocellular Carcinoma Progression by Activating the mTORC1 Signaling Pathway

Hepatocellular carcinoma (HCC) is a common malignant tumor with high mortality. Human phenylalanine tRNA synthetase (PheRS) comprises two α catalytic subunits encoded by the FARSA gene and two β regulatory subunits encoded by the FARSB gene. FARSB is a potential oncogene, but no experimental data show the relationship between FARSB and HCC progression. We found that the high expression of FARSB in liver cancer is closely related to patients' low survival and poor prognosis. In liver cancer cells, the mRNA and protein expression levels of FARSB are increased and promote cell proliferation and migration. Mechanistically, FARSB activates the mTOR complex 1 (mTORC1) signaling pathway by binding to the component Raptor of the mTORC1 complex to play a role in promoting cancer. In addition, we found that FARSB can inhibit erastin-induced ferroptosis by regulating the mTOR signaling pathway, which may be another mechanism by which FARSB promotes HCC progression. In summary, FARSB promotes HCC progression and is associated with the poor prognosis of patients. FARSB is expected to be a biomarker for early screening and treatment of HCC.

Sivelestat sodium alleviated lipopolysaccharide-induced acute lung injury by improving endoplasmic reticulum stress

Acute lung injury (ALI) is a common inflammatory respiratory disorder characterized by a high incidence and mortality rate. This study aimed to investigate the potential therapeutic effects of the neutrophil elastase inhibitor Sivelestat sodium (SIV) in improving endoplasmic reticulum stress (ERS) while treating lipopolysaccharide (LPS)-induced ALI. An ALI model was established using LPS induction. The effects of SIV on ALI were observed both in vivo and in vitro, along with its impact on ERS. Lung tissue damage was assessed using Hematoxylin-eosin (H&E) staining. Lung edema was measured by the lung wet/dry weight ratio. The expression levels of protein kinase R-like ER kinase (PERK), Phospho-protein kinase R-like ER kinase (p-PERK), activating transcription factor 4 (ATF4), eukaryotic translation initiation factor 2α (EIF2a), phosphorylated α subunit of eukaryotic initiation factor 2α (P-EIF2a), and C/EBP homologous protein (CHOP) were analyzed by Western blotting in vivo and in vitro. The levels of tumor necrosis factor-alpha (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6) in Lung tissue samples supernatants were measured by ELISA. Oxidative stress markers were measured by ELISA. Apoptosis was measured using the TUNEL assay. Apoptosis-associated proteins B-cell lymphoma-2 (Bcl-2)、Bcl2-associated × (Bax)、caspase-3 were evaluated through Western blotting in vivo and in vitro. The expression levels of ERS-related proteins, including p-PERK, ATF4, P-EIF2a, and CHOP, were significantly increased in the LPS-induced ALI model. However, SIV markedly reduced the expression levels of these proteins, suppressing the LPS-induced ERS response. Further investigations revealed that SIV exerted a protective effect on ALI by alleviating lung tissue damage and apoptosis, improving lung function, and reducing inflammation and oxidative stress levels. However, when SIV was co-administered with Tunicamycin (TUN), TUN blocked the beneficial effects of SIV on ERS and reversed the protective effects of SIV on ALI. In conclusion, SIV alleviated lung tissue damage and apoptosis, improving lung function, and reducing inflammation and oxidative stress in LPS-induced ALI by improving ERS.