XBP1 deficiency promotes hepatocyte pyroptosis by impairing mitophagy to activate mtDNA-cGAS-STING signaling in macrophages during acute liver injury

Exploration of ω-9MUFAs: Mitigating effect on lipopolysaccharide-induced acute lung injury

Given the demonstrated mitigating effect of omega-9 monounsaturated fatty acids (ω-9MUFAs) on lipopolysaccharide (LPS)-induced acute lung injury (ALI), we deeply explored corresponding mechanisms. Sprague-Dawley rats experienced ALI modeling, and received ω-9 MUFAs (3 mg/kg) injection via the tail vein. Post incubation in 100 ng/mL phorbol-12-myristate-13-acetate and 100 ng/mL LPS for 24 h each, THP-1 macrophages were transfected with shHSPH1 and c-MYC overexpression plasmid. Lung injury detection depended on H&E staining. Levels of inflammation-related factors were detected by ELISA. Levels of inflammation-related factors, heat shock protein family H (Hsp110) member 1 (HSPH1), c-MYC, stimulator of interferon response CGAMP interactor 1 (STING) and NOD-like receptor thermal protein domain associated protein 3 (NLRP3) were measured by qRT-PCR. Levels of pyroptosis-related factors, HSPH1, c-MYC, STING, NLRP3, and M1 macrophage biomarkers were assayed by Western blot. Proportion of M1 macrophages and pyroptosis were detected by flow cytometry. Localization of HSPH1 and CD68 was measured by immunofluorescence assay. ω-9MUFAs reduced the inflammation, the proportion of M1 and pyroptotic macrophages and levels of HSPH1, c-MYC, STING and NLRP3 in ALI rats. The expression positions of HSPH1 and CD68 were overlapped in ALI rat lung tissue. HSPH1 silencing reversed the changes in inflammation, the proportion of M1 and pyroptotic macrophages and levels of c-MYC, STING and NLRP3 in LPS-induced THP-1 macrophages, and c-MYC overexpression offset these effects of HSPH1 silencing. Collectively, ω-9MUFAs ameliorated LPS-induced ALI by regulating HSPH1/c-MYC expression, down-regulating M1 macrophage polarization and pyroptosis.

Ophiopogonin C protects against acute lung injury by fatal sepsis through pyroptosis macrophage

BACKGROUND

Sepsis is a frequent complication of severe infection and trauma, and one of the common causes of acute lung injury (ALI). Macrophage pyroptosis plays an important role in sepsis-induced ALI, takes part in the regulation of the inflammatory response, and affects the damage and repair of lung tissue.

PURPOSE

This study attempts to reveal the protective mechanism of Ophiopogonin C against fatal sepsis induced ALI.

METHODS

Mice were induced by cecum ligation and puncture (CLP), and treated with 5 (Low), 10 (Med) or 20 (High) mg/kg/day of Ophiopogonin C. Meanwhile, Single-cell data was used to analyze the specific cell lines of Sepsis patients. Molecular docking model also used to identify Protein interaction analysis for DEAD-Box Helicase 3 X-linked gene (DDX3X) binding regions on Nucleotide-binding domain (NBD), leucine-rich repeat (LRR), and pyrin domain (PYD)-containing protein 3 (NLRP3).

RESULTS

Ophiopogonin C protected against ALI in the sepsis model. Ophiopogonin C reduced inflammation of macrophage in the ALI sepsis model of ALI. Ophiopogonin C reduced pyroptosis macrophage in sepsis model of ALI. Pyroptosis macrophage is one important link for Ophiopogonin C in the ALI sepsis model. Ophiopogonin C suppressed NLRP3-induced pyroptosis macrophage in the ALI sepsis model. The up-regulation of DDX3X expression of macrophage in patients with fatal sepsis by Single-cell RNA sequencing. Ophiopogonin C suppressed DDX3X expression of macrophage in the ALI sepsis model. DDX3X is an important target spot for Ophiopogonin C in sepsis-induced ALI. Ophiopogonin C combined with the DDX3X protein at N-155 (Asn), R-488 (Arg), and d-506 (Asp) in macrophage. Ophiopogonin C reduced the interaction between the interconnection of DDX3X and NLRP3. Ophiopogonin C suppressed the DDX3X/ NLRP3 Signaling Pathway of human PBMCs by LPS+ATP through the inhibition of Pyroptosis.

CONCLUSION

These findings demonstrated that Ophiopogonin C safeguards against fatal sepsis-induced ALI through suppressing pyroptosis in macrophages through mitigating the interaction between DDX3X and NLRP3. Moreover, it offers a potential therapeutic target for fatal sepsis by aiming at the interaction between DDX3X and NLRP3 with Ophiopogonin C.

A mitochondria-targeted nanozyme with enhanced antioxidant activity to prevent acute liver injury by remodeling mitochondria respiratory chain

Developing nanomedicines with enhanced activity to scavenge reactive oxygen species (ROS) has emerged as a promising strategy for addressing ROS-associated diseases, such as drug-induced liver injury. However, designing nanozymes that not only remove ROS but also accelerate the repair of damaged liver cells remains challenging. Here, a two-pronged black phosphorus/Ceria nanozyme with mitochondria-targeting ability (TBP@CeO2) is designed. TBP@CeO2 nanozymes exhibit multienzyme activities and display significantly enhanced ROS scavenging capacity. They can effectively mitigate acetaminophen (APAP)-induced liver injury by scavenging excessive ROS and restoring mitochondrial complex II activity to promote energy-dependent liver cell repair. The in vitro experiments reveal that TBP@CeO2 nanozymes can effectively eliminate ROS and restore mitochondrial function, thereby decreasing the cytotoxicity on BRL 3A cells exposed to APAP/H2O2. The in vivo studies show that TBP@CeO2 nanozymes can improve the complex II activity and mitochondrial function in the liver, decreasing ROS and ensuring sufficient adenosine triphosphate (ATP) production, which helps protect the liver tissue against oxidative damage. This research introduces an innovative design strategy for nanozymes in the treatment of ROS-related diseases.

TJ0113-induced mitophagy in acute liver failure detected by Raman microspectroscopy

Impaired mitophagy underlies the pathophysiology of acute liver failure (ALF) and is closely associated with tissue damage and dysfunction. A novel mitophagy inducer, TJ0113, was used for treatment during ALF pathogenesis. In this study, we used a novel mitophagy inducer, TJ0113, to investigate the effects and mechanisms of TAA-induced ALF mice. The results showed that TJ0113 could enhance mitophagy through Parkin/PINK1 and ATG5 pathways, which in turn attenuated mitochondrial damage, hepatocyte apoptosis, nuclear factor (NF)-κB/NLRP3 signaling activation and inflammatory responses after TAA. Metabolomics results showed that TJ0113 mainly regulated lipid metabolism, amino acid metabolism and nucleotide metabolism in the livers of ALF mice. RNA sequencing (RNA-seq) analysis yielded that TJ0113 was involved in the development of ALF by regulating the P13K/AKT signaling pathway. The key highlight of this work is the use of an aberration-free line-scanning confocal Raman imager (AFLSCRI) to study the molecular changes in blood, liver tissue, gastrocnemius muscle, and mitochondrial extracts in ALF mice after TJ0113 treatment. Compared to the measurement with conventional assays, Raman microspectroscopy (micro-Raman) offers the benefits of being rapid, non-invasive, label-free and real-time. Our results found good agreement between Raman signals and histopathologic findings. The system has good performance with a spatial resolution of 2 μm, a spectral resolution of 4 cm-1 and a fast detection speed improved by 2 orders. Innovations in this test contribute to clinical diagnosis of disease, personalized treatment, effective intraoperative guidance and accurate prognosis. The data may help in the development of a non-invasive clinical device for mitochondrial damage using bedside micro-Raman.

Deficiency of myeloid NPC1 exacerbates liver injury and fibrosis by impairing macrophage efferocytosis

INTRODUCTION

Niemann-Pick C1 (NPC1), a lysosomal cholesterol transport protein, is required for efficient efferocytosis. Patients with Npc1 mutation are frequently accompanied with hepatic symptoms, including hepatomegaly, elevated liver transaminases, or even acute liver failure, but the pathogenic mechanism remains unknown.

OBJECTIVES

Our work aims to characterize the functional role of myeloid NPC1 in liver injury and elucidate its underlying mechanism.

METHODS

Analyses of injured livers from patients with liver diseases and mouse models were conducted to examine NPC1 expression. Myeloid cell-specific Npc1 knockout mice were constructed to determine the functional role of macrophage NPC1 in liver injury. Isolated macrophages were subjected to in vitro mechanistical assays.

RESULTS

We found that NPC1 is mainly expressed in hepatic macrophages. Its mRNA and protein expression are significantly elevated in injured livers from both patients and mouse models. Tissue-specific deletion of myeloid Npc1 increased liver inflammation, levels of serum liver function enzymes, and liver fibrosis in mouse models of liver injury induced by carbon tetrachloride (CCl4) injection and methionine-and-choline-deficient (MCD) diets. Further analyses indicate that Npc1 deficiency in mouse models of liver injury resulted in increased levels of serum HMGB1 and mitochondrial DNA, promoted hepatic macrophage proinflammatory activation, M1 polarization, led to overproduction of hepatic inflammatory cytokines/chemokines, e.g. CCL2 and STING/NFκB pathway activation. In vitro mechanistical studies reveal that Npc1-deficient macrophages exhibited inefficient efferocytosis, partly due to impaired cargo degradation.

CONCLUSIONS

These findings indicate that elevated expression of myeloid NPC1 in liver diseases protects liver from injury by promoting macrophage efferocytosis of damaged cells. Dysfunction of NPC1 aggravates liver injury, suggesting that NPC1 may be a potential therapeutic target for treating liver diseases.

cGAMP-targeting injectable hydrogel system promotes periodontal restoration by alleviating cGAS-STING pathway activation

The impaired function of periodontal ligament stem cells (PDLSCs) impedes restoration of periodontal tissues. The cGAS-cGAMP-STING pathway is an innate immune pathway that sensing cytosolic double-stranded DNA (dsDNA), but its role in regulating the function of PDLSCs is still unclear. In this study, we found that mitochondrial DNA (mtDNA) was released into the cytoplasm through the mitochondrial permeability transition pore (mPTP) in PDLSCs upon inflammation, which binds to cGAS and activated the STING pathway by promoting the production of cGAMP, and ultimately impaired the osteogenic differentiation of PDLSCs. Additionally, it is first found that inflammation can down-regulate the level of the ATP-binding cassette membrane subfamily member C1 (ABCC1, a cGAMP exocellular transporter) and ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1, a cGAMP hydrolase), which further aggravated the accumulation of intracellular cGAMP, leading to the persistent activation of the cGAS-STING pathway and thus the impaired the differentiation capacity of PDLSCs. Furthermore, we designed a hydrogel system loaded with a mPTP blocker, an ABCC1 agonist and ENPP1 to promote periodontal tissue regeneration by modulating the production, exocytosis, and clearance of cGAMP. In conclusion, our results highlight the profound effects, and specific mechanisms, of the cGAS-STING pathway on the function of stem cells and propose a new strategy to promote periodontal tissue restoration based on the reestablishment of cGAMP homeostasis.

Leucine enhances the cGAS-STING-NLRP3 pathway in autoimmune thyroiditis

Background

Branched-chain amino acids (BCAAs), including isoleucine (Ile), leucine (Leu), and valine (Val), are substrates for synthesising nitrogenous compounds and signalling molecules involved in regulating immunity. To date, data on the role of BCAAs in autoimmune thyroiditis (AIT) are lacking; therefore, this study aimed to determine the causality using two-sample Mendelian randomisation (MR) and explored the role of BCAAs in the cGAS-STING-NLRP3 pathway in vitro.

Methods

The causal relationship between BCAAs and the pathogenesis of AIT were identified using a two-sample MR study. The anti-inflammatory effects of BCAAs and their role in the cGAS-STING-NLRP3 pathway were investigated in lipopolysaccharide (LPS)- induced thyroid follicular cells (TFCs).

Results

Our findings indicate that BCAAs are a pathogenic factor for AIT (IVW OR = 4.960; 95 % CI = (1.54,15.940); P = 0.007). Leu significantly exacerbated the inflammatory response of thyroid cells, as evidenced by the up-regulation of tumour necrosis factor-alpha (TNF-α) and interleukin (IL)-6 and down-regulation of TGF-β1; simultaneously aggravated cellular injury and oxidative stress; significantly increased the expression of Sestrin2/p-mTOR and cGAS/STING/NLRP3 in AIT cells. Furthermore, the expression of IL-18 and IL-1β was significantly increased. Conversely, Leu deprivation induced cell injury, decreased oxidative stress, and inhibited Sestrin2/p-mTOR and cGAS/STING/NLRP3 pathways.

Conclusion

Our findings suggest a potential causal effect of genetically predicted Leu on AIT; Leu significantly exacerbated the inflammatory response and cellular damage in AIT cells. The mechanism by which Leu induces inflammation involves activating the promoted Sestrin2/mTOR and cGAS-STING-NLRP3 signalling pathways. Our study proposes a novel mechanism for the contributions of Leu in AIT and potential therapeutic strategies involving Leu deprivation in treating AIT.

S100A9/RAGE pathway regulation of mitophagy and the effect of JianPi LiShi YangGan formula in acute-on-chronic liver failure

ETHNOPHARMACOLOGICAL RELEVANCE

Mitophagy regulates cellular homeostasis and liver inflammation; however, it is inhibited in acute-on-chronic liver failure (ACLF), which drives disease progression. The JianPi LiShi YangGan formula (YGF) has the potential to improve inflammatory responses and reduce mortality in patients with ACLF. However, the precise mechanisms underlying these effects remain unknown.

AIM OF THE STUDY

We investigated the role of S100A9/RAGE signaling in mitophagy and the protective effects of traditional Chinese medicinal compounds on ACLF.

MATERIALS AND METHODS

An ACLF mouse model was established using carbon tetrachloride, lipopolysaccharide, and d-galactose. Hematoxylin and eosin staining and enzyme-linked immunosorbent assay were employed to evaluate the hepatoprotective effect of YGF in ACLF mice. Mitochondrial damage was assessed using transmission electron microscopy. Protein levels of mitophagy-related indicators were assessed through immunohistochemistry and western blotting, and immunofluorescence staining was performed to observe Lamp2 and COX-IV co-localization.

RESULTS

The hepatocytes of ACLF mice contained damaged mitochondria, decreased mitophagy-related protein (Pink1, Parkin, and LC3B) expression and activated S100A9/RAGE signaling. Inhibiting S100A9 or RAGE improved liver injury in ACLF mice and enhanced Lamp2-COX-IV co-localization. In alpha mouse liver 12 (AML12) cells overexpressing RAGE, recombinant S100A9 protein inhibited mitophagy induced by 3-chlorocarbonyl benzoyl chloride. YGF reduced mitochondrial damage, increased Pink1, Parkin, and LC3B levels, and enhanced mitophagy while inhibiting S100A9/RAGE activation in the hepatocytes of ACLF mice.

CONCLUSIONS

This study found that S100A9/RAGE pathway activation impairs mitophagy, and YGF alleviates liver injury by downregulating S100A9 and RAGE signaling, which may be a novel therapeutic strategy for ACLF.

Arginase 1 drives mitochondrial cristae remodeling and PANoptosis in ischemia/hypoxia-induced vascular dysfunction

Ischemic/hypoxic injury significantly damages vascular function, detrimentally impacting patient outcomes. Changes in mitochondrial structure and function are closely associated with ischemia/hypoxia-induced vascular dysfunction. The mechanism of this process remains elusive. Using rat models of ischemia and hypoxic vascular smooth muscle cells (VSMCs), we combined transmission electron microscopy, super-resolution microscopy, and metabolic analysis to analyze the structure and function change of mitochondrial cristae. Multi-omics approaches revealed arginase 1 (Arg1) upregulation in ischemic VSMCs, confirmed by in vivo and in vitro knockout models showing Arg1's protective effects on mitochondrial cristae, mitochondrial and vascular function, and limited the release of mtDNA. Mechanistically, Arg1 interacting with Mic10 led to mitochondrial cristae remodeling, together with hypoxia-induced VDAC1 lactylation resulting in the opening of MPTP and release of mtDNA of VSMCs. The released mtDNA led to PANoptosis of VSMCs via activation of the cGAS-STING pathway. ChIP-qPCR results demonstrated that lactate-mediated Arg1 up-regulation was due to H3K18la upregulation. VSMCs targeted nano-material PLGA-PEI-siRNA@PM-α-SMA (NP-siArg1) significantly improved vascular dysfunction. This study uncovers a new mechanism of vascular dysfunction following ischemic/hypoxic injury: a damaging positive feedback loop mediated by lactate-regulated Arg1 expression between the nucleus and mitochondria, leading to mitochondria cristae disorder and mtDNA release, culminating in VSMCs PANoptosis. Targeting VSMCs Arg1 inhibition offers a potential therapeutic strategy to alleviate ischemia/hypoxia-induced vascular impairments.

Tumor microenvironment responsive Mn-based nanoplatform activate cGAS-STING pathway combined with metabolic interference for enhanced anti-tumor therapy

Despite the encouraging developments in tumor immunotherapy, the complex tumor microenvironment (TME) and abnormal energy metabolism persist as key factors facilitating immune escape. Recent research has emphasized the significant potential of the Manganese ions (Mn2+) as a "immune ion reactors" have the potential to stimulate cGAS-STING signaling pathway in modulating tumor immunotherapy. However, their efficacy is limited by insufficient targeting and lack of tumor specificity. To address these challenges, we have developed a nano-drug named as LT@MnO@MON-HA (LMMH), which incorporates manganese oxide (MnO) nanoparticles as the core and organic mesoporous silica as the outer layer. The mitochondrial glycolysis inhibitor lonidamine (LT) is encapsulated within the mesopores of LMMH and subsequently coated with hyaluronic acid to achieve precise tumor-targeted drug delivery. After reaching the tumor site, LMMH can decompose in the reducing and acidic TME, releasing LT and Mn2+. Once internalized by cells, LT rapidly localizes to mitochondria via functional groups, disrupting mitochondrial metabolism and increasing intracellular reactive oxygen species levels. Mn2+ catalyze the conversion of hydrogen peroxide (H₂O₂) into more cytotoxic hydroxyl radicals (·OH), thereby enhancing chemodynamic therapy (CDT). The mesoporous silica shell of LMMH is capable of depleting glutathione in the TME, enhancing CDT. Moreover, LMMH functions as an agonist of the cGAS-STING pathway, stimulating cytokine release and activating effector T cells, which in turn triggering systemic immune responses against primary and metastatic cancers. Collectively, these finding highlights the dual mechanisms by which LMMH enhances combination immunotherapy by regulating the TME and tumor metabolism.

New Evidence for the Mechanisms of Nanoplastics Amplifying Cadmium Cytotoxicity: Trojan Horse Effect, Inflammatory Response, and Calcium Imbalance

Nanoplastics (NPs) are emerging pollutants worldwide. Particularly worrisome is that although studies have reported that NPs can amplify the biotoxicity of environmental pollutants, the specific mechanism remains unclear. Here, we found that NPs, even without significant toxicity (cell survival: 99.11%), amplified the hepatocyte toxicity of Cd2+. Mechanistically, higher Cd2+ uptake (Δ = 23.80%) combined with crucial intracellular desorption behavior of Cd2+ loaded in NPs (desorption rate: 82.70%) were identified as prerequisites for NPs amplifying Cd2+ cytotoxicity. As for toxigenic pathways, the inflammatory response and calcium (Ca) signaling pathway were identified as the primary molecular events leading to the amplification of Cd2+ cytotoxicity. Further phenotypic monitoring revealed that NPs synergized with Cd2+ to induce more severe pyroptosis and apoptosis by activating the inflammatory caspase-1-dependent and Ca2+-mitochondrial-caspase-3 pathways to a greater extent, respectively. This study reveals and proves for the first time the "Trojan horse" effects of NPs, thus elucidating the actual mechanisms by which NPs act as toxicity amplifiers of pollutants, providing significant insights into accurate risk assessment of NPs in composite pollution.

Targeting Lp-PLA2 inhibits profibrotic monocyte-derived macrophages in silicosis through restoring cardiolipin-mediated mitophagy

Monocyte-derived macrophages (MoMacs) are the most important effector cells that cause pulmonary fibrosis. However, the characteristics of MoMac differentiation in silicosis and the mechanisms by which MoMacs affect the progression of pulmonary fibrosis remain unclear. Integration of single-cell and spatial transcriptomic analyses revealed that the silicosis niche was occupied by a subset of MoMacs, identified as Spp1hiMacs, which remain in an immature transitional state of differentiation during silicosis. This study investigated the mechanistic foundations of mitochondrial damage induced by the lipoprotein-associated phospholipase A2 (Lp-PLA2, encoded by Pla2g7)-acyl-CoA:lysocardiolipin acyltransferase-1 (ALCAT1)-cardiolipin (CL) signaling pathway, which interferes with Spp1hiMac differentiation. We demonstrated that in SiO2-induced MoMacs, Lp-PLA2 induces abnormal CL acylation through the activation of ALCAT1, resulting in impaired mitochondrial localization of PINK1 and LC3B and mitochondrial autophagy defects. Simultaneously, lysosomal dysfunction causes the release of the lysosomal protein cathepsin B into the cytoplasm, which involves M1 and M2 macrophage polarization and the activation of proinflammatory and profibrotic pathways. Furthermore, we assessed the efficacy of the Lp-PLA2 inhibitor darapladib in ameliorating silica-induced pulmonary fibrosis in a murine model. Our findings enhance our understanding of silicosis pathogenesis and offer promising opportunities for developing targeted therapies to mitigate fibrotic progression and maintain lung function in affected individuals.

Impaired Mitophagy Contributes to Pyroptosis in Sarcopenic Obesity Zebrafish Skeletal Muscle

Background: Growing evidence suggests that the prevalence of sarcopenic obesity (SOB) is on the rise across the globe. However, the key molecular mechanisms behind this disease have not been clarified. Methods: In this experiment, we fed zebrafish a high-fat diet (HFD) for 16 weeks to induce sarcopenic obesity. Results: After a dietary trial, HFD zebrafish exhibited an obese phenotype with skeletal muscle atrophy and decreased swimming capacity. We demonstrated that mitochondrial content and function were abnormal in SOB zebrafish skeletal muscle. These results may be associated with the impairment of mitophagy regulated by the PTEN-induced putative kinase 1 (PINK1)/Parkin (PRKN) pathway. In addition, we also found that NOD-like receptor protein 3 (NLRP3)/gasdermin D (GSDMD) signaling was activated with the upregulation of NLRP3, GSDMD-NT, and mature-IL1β, which indicated that pyroptosis was induced in SOB zebrafish skeletal muscle. Conclusions: Our study identified that impaired mitophagy and pyroptosis were associated with the pathogenesis of SOB. These results could potentially offer novel therapeutic objectives for the treatment of sarcopenic obesity.

Hyperandrogenism triggers mtDNA release to participate in ovarian inflammation via mPTP/cGAS/STING in PCOS

Hyperandrogenism induced ovarian inflammation is associated with the pathogenesis of polycystic ovary syndrome (PCOS), but the specific mechanism behind it remains unclear. The aim of this study was to elucidate the association between mitochondrial DNA-cGAS-STING pathway and PCOS inflammatory response. RNA sequencing analysis and other experiments showed that inflammatory pathways were activated, mitochondria were damaged, and mtDNA-cGAS-STING pathways were activated in PCOS women. In vitro, after stimulation of KGN cells with testosterone, the expression of pro-inflammatory factors was enhanced and the cGAS-STING pathway was activated. Stimulator of the interferon genes (STING) knockout can reduce testosterone-induced inflammatory response and improve follicular function. Cyclosporin A therapy reduces cytoplasmic mtDNA, blocks cGAS-STING pathway activation, alleviates inflammatory markers, and reverses abnormal follicular function. In vivo experiments have shown that inhibiting STING can reduce ovarian dysfunction and inflammation in PCOS patients. Hyperandrogenism in PCOS can trigger mitochondrial permeability transition pore (mPTP) overopening, leading to mtDNA release and cGAS-STING pathway activation, causing inflammation and follicle damage.

Rutin ameliorates LPS-induced acute lung injury in mice by inhibiting the cGAS-STING-NLRP3 signaling pathway

Introduction

Acute lung injury (ALI) and its severe form, acute respiratory distress syndrome (ARDS), represent critical respiratory failures with high mortality rates and limited treatment options. While the flavonoid rutin exhibits documented anti-inflammatory and antioxidant properties, its therapeutic mechanisms in ALI/ARDS remain unclear. This study investigated rutin's efficacy against lipopolysaccharide (LPS)-induced ALI in mice, with a mechanistic focus on the cGAS-STING pathway and NLRP3 inflammasome activation.

Methods

Male C57BL/6 mice were divided into Vehicle control, LPS induction, LPS + rutin co-treatment, and Rutin monotherapy groups. ALI was induced by intratracheal LPS challenge, and rutin was administered via gavage. Proteomics analysis, histological evaluation, immunohistochemistry, TUNEL staining, immunofluorescence, RT-qPCR, western blot, ELISA, and oxidative stress assays were performed to assess the effects of rutin on ARDS.

Results

The proteomic profiling of lung tissues from LPS-challenged mice identified significant dysregulation of proteins integral to the cGAS-STING cascade and pyroptotic processes. Gene ontology and KEGG pathway analyses underscored the pivotal role of immune and inflammatory responses in ALI, particularly in cytosolic DNA-sensing and NOD-like receptor signaling pathways. Rutin administration significantly alleviated LPS-induced lung injury, reducing oxidative stress, apoptosis, and proinflammatory cytokine levels (IL-6, IL-1β, TNF-α). Mechanistically, rutin demonstrated dual suppression: 1) inhibiting cGAS-STING activation through decreased expression of cGAS, STING, and phosphorylation of TBK1/IRF3 (P<0.05), and 2) attenuating NLRP3-mediated pyroptosis via downregulation of NLRP3-ASC-caspase1-GSDMD signaling (P<0.05). Pharmacological STING inhibition (C-176) validated the cGAS-STING-NLRP3 regulatory hierarchy in ALI pathogenesis.

Conclusion

These findings elucidate rutin's novel therapeutic mechanism through coordinated suppression of the cGAS-STING-NLRP3 axis, positioning it as a promising candidate for ALI/ARDS intervention.

Mitochondria-dependent innate immunity: A potential therapeutic target in Flavivirus infection

Mitochondria, known as the powerhouse of cells, play a crucial role in host innate immunity during flavivirus infections such as Dengue, Zika, West Nile, and Japanese Encephalitis Virus. Mitochondrial antiviral signaling protein (MAVS) resides on the outer mitochondrial membrane which is triggered by viral RNA recognition by RIG-I-like receptors (RLRs). This activation induces IRF3 and NF-κB signaling, resulting in type I interferon (IFN) production and antiviral responses. Upon flavivirus infection, mitochondrial stress and dysfunction may lead to the release of mitochondrial DNA (mtDNA) into the cytoplasm, which serves as a damage-associated molecular pattern (DAMP). Cytosolic mtDNA is sensed by cGAS (cyclic GMP-AMP synthase), leading to the activation of the STING (Stimulator of Interferon Genes) pathway to increase IFN production and expand inflammation. Flaviviral proteins control mitochondrial morphology by controlling mitochondrial fission (MF) and fusion (MFu), disrupting mitochondrial dynamics (MD) to inhibit MAVS signaling and immune evasion. Flaviviral proteins also cause oxidative stress, resulting in the overproduction of reactive oxygen species (ROS), which triggers NLRP3 inflammasome activation and amplifies inflammation. Additionally, flaviviruses drive metabolic reprogramming by shifting host cell metabolism from oxidative phosphorylation (OxPhos) to glycolysis and fatty acid synthesis, creating a pro-replicative environment that supports viral replication and persistence. Thus, the present review explores the complex interaction between MAVS, mtDNA, and the cGAS-STING pathway, which is key to the innate immune response against flavivirus infections. Understanding these mechanisms opens new avenues in therapeutic interventions in targeting mitochondrial pathways to enhance antiviral immunity and mitigate viral infection.

Dihydroartemisinin Attenuates Radiation-Induced Lung Injury by Inhibiting the cGAS/STING/NF-κB Signaling Pathway

Dihydroartemisinin (DHA) is a derivative of artemisinin, which affects inflammation, oxidative stress, and immune regulation. However, the mechanism underlying its effects remains largely unknown. This study aims to explore the mechanism by which DHA affects radiation-induced lung injury (RILI), providing new insights for lung radiotherapy. To elucidate its mechanism of action, C57BL/6 J mice were irradiated with 15 Gy whole chest. RILI was evaluated by qRT-PCR, ELISA, histology, Western blot analysis, immunohistochemistry, and RILI signaling cascade studies. In addition, small interfering RNAs were employed to knockdown cGAS proteins in the cGAS-STING signaling pathway in the human bronchial epithelium cell line (BEAS-2B). Both In Vivo and Vitro experiments were conducted to investigate the specific mechanism by which DHA alleviated RILI. We observed the activation of the cGAS-STING pathway, along with the phosphorylation of the downstream target NF-κB and an increase in inflammatory factor levels in the mouse model following radiation exposure. In the cell model, irradiation also triggered the activation of the cGAS-STING signaling pathway and its downstream targets, leading to elevated levels of inflammatory factors. Notably, knocking down the cGAS using small interfering RNA in the BEAS-2B cells significantly alleviated RILI in the cell model. Our study elucidated the mechanism of DHA reducing RILI through the cGAS/STING/NF-κB signaling pathway, and revealed that the GAS/STING/NF-κB axis may be a potential therapeutic target for RILI.

Effect of quercetin on inhibiting gefitinib‑activated non‑small cell lung cancer‑induced cell pyroptosis in cardiomyocytes via modulating mitochondrial autophagy mediated by the SHP2/ROS/AMPK/XBP‑1/DJ‑1 signaling pathway

It has been reported that treatment of patients with non‑small cell lung cancer (NSCLC) with gefitinib increases the risk of QT interval prolongation. Therefore, the present study aimed to investigate whether quercetin could delay gefitinib‑induced cardiomyocyte apoptosis and its underlying mechanism. A total of 32 nude mice were divided into the sham, NSCLC, NSCLC + gefitinib and NSCLC + gefitinib + quercetin groups. Cardiac fibrosis in mouse heart tissues was assessed by Masson's trichrome staining. Additionally, immunohistochemical staining was performed to detect the expression levels of Src homology‑2 domain‑containing protein tyrosine phosphatase (SHP2), X‑box binding protein 1 (XBP‑1), phosphorylated (p)‑stimulator of interferon genes (STING) and Nod‑like receptor protein 3. Bioinformatics analysis was carried auto to predict the association between quercetin and the SHP2/reactive oxygen species (ROS) axis. Furthermore, the effects of adenosine triphosphate (ATP) + gefitinib, SHP2 silencing and H2O2 on ROS levels, as well as on the p‑AMP‑activated protein kinase (AMPK)/XBP‑1/Parkinsonism associated deglycase (DJ‑1) axis, mitochondrial autophagy and apoptosis were assessed via detecting the expression levels of the corresponding proteins in cardiomyocytes by western blot analysis. JC‑1 immunofluorescence was performed to evaluate mitochondrial membrane damage. The results showed that NSCLC could not significantly affect cardiac function. In addition, compared with NSCLC alone, ventricular fibrosis was exacerbated in the NSCLC + gefitinib group. However, treatment with quercetin inhibited gefitinib‑induced ventricular fibrosis, activated the gefitinib‑suppressed SHP2 protein expression and downregulated the gefitinib‑induced XBP‑1 and p‑STING expression. Furthermore, the bioinformatics analysis results predicted that quercetin could interact with SHP2/ROS. The in vitro experiments demonstrated that the expression levels of the ROS‑related proteins, namely NADPH oxidase 4 and XBP‑1/DJ‑1, and those of the mitochondrial autophagy‑ and apoptosis‑related proteins were enhanced, while those of p‑AMPK, were reduced in cardiomyocytes of the NSCLC + ATP + gefitinib group. However, cell treatment with quercetin inhibited ROS production and the expression levels of XBP‑1/DJ‑1 and apoptosis‑related proteins activated by NSCLC + ATP + gefitinib. By contrast, quercetin activated the expression levels of mitochondrial autophagy‑related proteins and those of p‑AMPK. Furthermore, SHP2 silencing and cell treatment with H2O2 could separately inhibit the NSCLC + ATP + gefitinib‑induced expression of mitochondrial autophagy‑related proteins and p‑AMPK, while they could promote ROS production and upregulate XBP‑1/DJ‑1 and apoptosis‑related proteins. In summary, the results of the current study revealed a promising therapeutic approach for addressing cardiac issues caused by gefitinib treatment in patients with NSCLC. Therefore, quercetin could inhibit the gefitinib‑induced NSCLC‑mediated cardiomyocyte apoptosis via regulating the SHP2/ROS/AMPK/XBP‑1/DJ‑1 signaling pathway through mitochondrial autophagy.

Immp2l gene knockout induces granulosa cell senescence by activation of cGAS-STING pathway via TFAM-mediated mtDNA leakage

Granulosa cell-produced inflammatory factors may be key contributors to ovarian dysfunction, and Immp2l deficiency accelerates ovarian aging via granulosa cell senescence; however, the role of inflammation in granulosa cell senescence is largely unknown. Therefore, in this study, cGAS-STING-mediated inflammation was explored in Immp2l deficiency-induced granulosa cell senescence. Immp2l deficiency led to senescence-associated secretory phenotype (SASP) and granulosa cell senescence. Immp2l knockout caused mitochondrial dysfunction and mitochondrial DNA (mtDNA) leakage into the cytoplasm. The cytoplasmic mtDNA was recognized by the DNA-sensing molecule cGAS-STING, which activates cGAS-STING and key downstream interferon-stimulated genes (ISGs) and then promotes the secretion of proinflammatory factors, leading to SASP in senescent granulosa cells. Interestingly, the mitochondrial inner membrane pore protein (Cyclophilin D40) CyPD40 and the outer membrane pore protein voltage-dependent-anion channel 1 (VDAC1) were markedly increased in senescent granulosa cells, accompanied by significantly increased expression of the mtDNA stability protein mitochondrial transcription factor A (TFAM). Downregulation of TFAM with siRNA in senescent granulosa cells improved mitochondrial function, significantly decreased mtDNA in the cytoplasm, inhibited the cGAS-STING pathway and markedly decreased CyPD40 and VDAC1 protein levels in TFAM-treated senescent granulosa cells. The SASP phenotype was also alleviated. In addition, senescent granulosa cells were treated with procyanidin B2 (PCB2), which has anti-inflammatory effects, and the TFAM-mediated mtDNA-cGAS-STING pathway was inhibited, accompanied by a markedly reduced SASP phenotype and granulosa cell senescence. In conclusion, Immp2l gene knockout induced granulosa cell senescence by activation of the cGAS-STING pathway via TFAM-mediated mtDNA leakage into the cytoplasm through the CyPD40 and the VDAC1.

Mitochondrial Dysfunction as a Pathogenesis and Therapeutic Strategy for Metabolic-Dysfunction-Associated Steatotic Liver Disease

Metabolic-dysfunction-associated steatotic liver disease (MASLD) has emerged as a significant public health concern, attributed to its increasing prevalence and correlation with metabolic disorders, including obesity and type 2 diabetes. Recent research has highlighted that mitochondrial dysfunction can result in the accumulation of lipids in non-adipose tissues, as well as increased oxidative stress and inflammation. These factors are crucial in advancing the progression of MASLD. Despite advances in the understanding of MASLD pathophysiology, challenges remain in identifying effective therapeutic strategies targeting mitochondrial dysfunction. This review aims to consolidate current knowledge on how mitochondrial imbalance affects the development and progression of MASLD, while addressing existing research gaps and potential avenues for future research. This review was conducted after a systematic search of comprehensive academic databases such as PubMed, Embase, and Web of Science to gather information on mitochondrial dysfunction as well as mitochondrial-based treatments for MASLD.

The Nb4C3 MXenzyme Attenuates MASH by Scavenging ROS in a Mouse Model

Objective

The incidence of metabolic dysfunction-associated steatohepatitis (MASH) is increasing because people's dietary habits are dominated by high caloric intake and sedentary lifestyles, leading to the accumulation of lipid, reactive oxygen species (ROS) and inflammation. However, treating MASH remains a challenge.

Methods

Two-dimensional (2D) niobium carbide (Nb4C3) MXene nanoenzymes (MXenzymes) possess both antioxidant and anti-inflammatory properties and have attracted considerable attention in the tumor and engineering fields. The Nb4C3 MXenzyme was developed for MASH therapy and exhibited biosafety and antilipid peroxidation activity.

Results

Nb4C3 reduced excessive ROS and proinflammatory cytokine levels through its antilipid peroxidation activities, resulting in the inhibition of hepatocyte lipid accumulation and inflammation in a methionine-choline-deficient diet (MCD)-induced murine MASH model. Mechanistically, Nb4C3 not only inhibited lipid accumulation and disrupted lipid metabolism in hepatocytes but also attenuated fatty acid-induced cell death by reducing intracellular ROS levels, which significantly promoted the polarization of M1 macrophages to M2 macrophages by alleviating oxidative stress and suppressing inflammatory factor expression.

Conclusion

The Nb4C3 MXenzyme can be used as a multifunctional bioactive material to alleviate hepatic steatosis and inflammation in MASH mice through its robust antioxidant and anti-inflammatory activities.

Polymer-Encapsulated Catalase for Targeted Redox Regulation in Acute Liver Injury

The liver plays a critical role in maintaining homeostasis, and its dysfunction can lead to severe conditions like acute liver injury (ALI), which is primarily caused by viral infections, toxins, and oxidative stress. Reactive oxygen species (ROS), especially hydrogen peroxide (H₂O₂), significantly drive hepatocyte injury, initiating oxidative stress and inflammation. Current antioxidants, such as N-acetylcysteine (NAC) and superoxide dismutase (SOD), show limited clinical efficacy due to poor targeting, instability, and toxicity. Catalase (CAT), an essential enzyme for H₂O₂ decomposition, represents a promising therapeutic for ALI; however, its clinical application faces challenges in stability, rapid degradation, and insufficient targeting. Here, a novel nanocapsule-based CAT delivery system (n(CAT)) is presented, formed through in situ radical polymerization using 2-methacryloyloxyethyl phosphorylcholine (MPC) and N-(3-aminopropyl)-methacrylamide hydrochloride (APM). This strategy significantly enhances CAT's stability, retains enzyme activity, and improves selective liver accumulation, particularly at inflammation sites. The results demonstrate that n(CAT) effectively reduces oxidative stress, minimizes inflammation, and facilitates liver repair in ALI and ischemia-reperfusion injury (IRI) models. These findings highlight the potential of n(CAT) as a promising platform for advanced antioxidant therapies targeting liver diseases, including hepatitis.

A20 attenuates oxidized self-DNA-mediated inflammation in acute kidney injury

The ubiquitin-editing enzyme A20 is known to regulate inflammation and maintain homeostasis, but its role in self-DNA-mediated inflammation in acute kidney injury (AKI) is not well understood. Here, our study demonstrated that oxidized self-DNA accumulates in the serum of AKI mice and patients. This oxidized self-DNA exacerbates the progression of AKI by activating the cGAS-STING pathway and NLRP3 inflammasome. While inhibition of the STING pathway only slightly attenuates AKI progression, suppression of NLRP3 inflammasome-mediated pyroptosis significantly alleviates AKI progression and improves the survival of AKI mice. Subsequently, we found that Tnfaip3 (encoding A20) is significantly upregulated following oxidized self-DNA treatment. A20 significantly alleviates AKI development by dampening STING signaling pathway and NLRP3-mediated pyroptosis. Moreover, A20-derived peptide (P-II) also significantly alleviates ox-dsDNA-induced pyroptosis and improves the survival and renal injury of AKI mice. Mechanistically, A20 competitively binds with NEK7 and thus inhibiting NLRP3 inflammasome. A20 and P-II interfere with the interaction between NEK7 and NLRP3 through Lys140 of NEK7. Mutation of Lys140 effects on the interaction of NEK7 with A20 and/or NLRP3 complex. Conditional knockout of NEK7 in macrophages or pharmacological inhibition of NEK7 both significantly rescue AKI mouse models. This study reveals a new mechanism by which A20 attenuates oxidized self-DNA-mediated inflammation and provides a new therapeutic strategy for AKI.

Reprogramming Glucose Metabolism of Macrophage for Acute Liver Failure Therapy with Itaconate Lipo-Nanodrug

Acute liver failure (ALF) is a life-threatening disease featuring comprehensive inflammatory response and metabolic disorders in which macrophages exert central roles. A glucose metabolism mediator of macrophages, itaconate, has demonstrated potent anti-inflammatory efficacy in various diseases, implying that itaconate could work in treating ALF. However, systemic administration of itaconate may lead to immune disorder, making targeting the delivery of itaconate to the liver lesion area highly important. Herein, a liposomal nanodrug incorporating itaconate is developed, and its potential in treating acute liver failure in an ALF murine model established by LPS/D-GalN administration is tested. The nanodrug shows preferential liver accumulation to effectively alleviate LPS/D-GalN-induced hepatic histopathological injury by decreasing oxidative stress. Moreover, it reprograms the glucose metabolism of macrophages, resulting in macrophage repolarization toward the anti-inflammatory phenotype. Furthermore, western-blot and immunohistochemical assays verifies that the nanodrug may inhibit aerobic glycolysis of macrophages in an NRF2 and STING-dependent manner. These results underline the promise of the nanodrug for ALF treatment by reprogramming glucose metabolism.

Ocifisertib alleviates the gasdermin D-independent pyroptosis of nucleus pulposus cells by targeting GSDME

This study aimed to elucidate the cellular and molecular mechanisms of GSDME in GSDMD independent nucleus pulposus (NP) cell pyroptosis. We analyzed microarray datasets to identify differentially expressed genes (DEGs) in the progression of intervertebral disc degeneration (IDD) and conducted Gene Ontology analysis to elucidate DEGs-participated biological processes. We utilized lipopolysaccharides (LPS) to treat human primary NP cells to establish pyroptosis cell model. And siRNA was used to simulate a GSDMD-deficient environment. We used several regulators to figure out how GSDME was participate in pyroptosis via a GSDMD independent pathway. The molecular docking was conducted to identify compound that could possibly bind to GSDME and suppress its cleavage. Finally, Ocifisertib was intraperitoneally administered into IDD rat model to explore its therapeutic potential. Pyroptosis was activated in IDD. In vitro, LPS induced NP cell pyroptosis by promoting the cleavage of GSDMD and GSDME. In the absence of GSDMD, the cleavage of GSDME compensatively upregulated to mediate pyroptosis. Ocifisertib alleviated pyroptosis-mediated IDD by inhibiting GSDME cleavage in annulus fibrosus puncture-induced IDD rat model. Our study provides evidence that the cleavage of GSDME aggravates IDD by accelerating NP cell pyroptosis and demonstrates that Ocifisertib has therapeutic potential in IDD treatment.

PINK1-mediated mitophagy attenuates pathological cardiac hypertrophy by suppressing the mtDNA release-activated cGAS-STING pathway

AIMS

Sterile inflammation is implicated in the development of heart failure (HF). Mitochondria play important roles in triggering and maintaining inflammation. Mitophagy is important for regulation of mitochondrial quality and maintenance of cardiac function under pressure overload. The association of mitophagy with inflammation in HF is largely unclear. As PINK1 is a central mediator of mitophagy, our objective was to investigate its involvement in cardiac hypertrophy, and the effect of PINK1-mediated mitophagy on cGAS-STING activation during cardiac hypertrophy.

METHODS AND RESULTS

PINK1 knockout and cardiac-specific PINK1-overexpressing transgenic mice were created and subsequently subjected to transverse aortic constriction (TAC) surgery. In order to explore whether PINK1 regulates STING-mediated inflammation during HF, PINK1/STING (stimulator of interferon genes) double-knockout (DKO) mice were created. Pressure overload was induced by TAC. Our findings indicate a significantly decline in PINK1 expression in TAC-induced hypertrophy. Cardiac hypertrophic stimuli caused the release of mitochondrial DNA (mtDNA) into the cytosol, activating the cGAS-STING signalling, which in turn initiated cardiac inflammation and promoted the progression of cardiac hypertrophy. PINK1 deficiency inhibited mitophagy activity, promoted mtDNA release, and then drove the overactivation of cGAS-STING signalling, exacerbating cardiac hypertrophy. Conversely, cardiac-specific PINK1 overexpression protected against hypertrophy thorough inhibition of the cGAS-STING signalling. DKO mice revealed that the effects of PINK1 on hypertrophy were dependent on STING.

CONCLUSION

Our findings suggest that PINK1-mediated mitophagy plays a protective role in pressure overload-induced cardiac hypertrophy via inhibiting the mtDNA-cGAS-STING pathway.

ATG16L1 restrains macrophage NLRP3 activation and alveolar epithelial cell injury during septic lung injury

BACKGROUND

The lung is the organ most commonly affected by sepsis. Additionally, acute lung injury (ALI) resulting from sepsis is a major cause of death in intensive care units. Macrophages are essential for maintaining normal lung physiological functions and are implicated in various pulmonary diseases. An essential autophagy protein, autophagy-related protein 16-like 1 (ATG16L1), is crucial for the inflammatory activation of macrophages.

METHODS

ATG16L1 expression was measured in lung from mice with sepsis. ALI was induced in myeloid ATG16L1-, NLRP3- and STING-deficient mice by intraperitoneal injection of lipopolysaccharide (LPS, 10 mg/kg). Using immunofluorescence and flow cytometry to assess the inflammatory status of LPS-treated bone marrow-derived macrophages (BMDMs). A co-culture system of BMDMs and MLE-12 cells was established in vitro.

RESULTS

Myeloid ATG16L1-deficient mice exhibited exacerbated septic lung injury and a more intense inflammatory response following LPS treatment. Mechanistically, ATG16L1-deficient macrophages exhibited impaired LC3B lipidation, damaged mitochondria and reactive oxygen species (ROS) accumulation. These abnormalities led to the activation of NOD-like receptor family pyrin domain-containing protein 3 (NLRP3), subsequently enhancing proinflammatory response. Overactivated ATG16L1-deficient macrophages aggravated the damage to alveolar epithelial cells and enhanced the release of double-stranded DNA (dsDNA), thereby promoting STING activation and subsequent NLRP3 activation in macrophages, leading to positive feedback activation of macrophage NLRP3 signalling. Scavenging mitochondrial ROS or inhibiting STING activation effectively suppresses NLRP3 activation in macrophages and alleviates ALI. Furthermore, overexpression of myeloid ATG16L1 limits NLRP3 activation and reduces the severity of ALI.

CONCLUSIONS

Our findings reveal a new role for ATG16L1 in regulating macrophage NLRP3 feedback activation during sepsis, suggesting it as a potential therapeutic target for treating sepsis-induced ALI.

KEY POINTS

Myeloid-specific ATG16L1 deficiency exacerbates sepsis-induced lung injury. ATG16L1-deficient macrophages exhibit impaired LC3B lipidation and ROS accumulation, leading to NLRP3 inflammasome activation. Uncontrolled inflammatory responses in ATG16L1-deficient macrophages aggravate alveolar epithelial cell damage. Alveolar epithelial cells release dsDNA, activating the cGAS-STING-NLRP3 signaling pathway, which subsequently triggers a positive feedback activation of NLRP3. Overexpression of ATG16L1 helps mitigate lung tissue inflammation, offering a novel therapeutic direction for sepsis-induced lung injury.

IL-27 aggravates acute hepatic injury by promoting macrophage M1 polarization to induce Caspase-11 mediated Pyroptosis in vitro and in vivo

OBJECTIVES

Our aim was to explore the IL-27 effect in sepsis (SP)-related acute hepatic injury (AHI) as well as its possible mechanism.

MATERIALS AND METHODS

Herein, we utilized both wild-type (WT) and IL-27 receptor (WSX-1)-deficient (IL-27R-/-) mice alongside RAW264.7 cells. Our study established an SP-associated AHI model through the intraperitoneal injections of lipopolysaccharide (LPS) + D-galactosamine (D-G). For examining the IL-27 impact on AHI, mice serum and liver tissue samples were gathered. Inflammatory factor levels in the liver and serum were detected using ELISA and immunohistochemistry. Immunofluorescence and Western blot techniques were employed for the detection of protein expression associated with polarization and pyroptosis in the liver, including iNOS, ARG-1, caspase-11, RAGE, and GSDMD. To further verify the IL-27 effects on macrophage polarization and pyroptosis and explore possible mechanisms involved, we used LPS-triggered RAW264.7 macrophages to assess AMPK/SIRT1 expression after IL-27 intervention. This study utilized Compound C (CC) to block the AMPK/SIRT1 pathway. The inflammatory response level and protein expression related to macrophage polarization and pyroptosis were measured again to reveal IL-27 implication in AHI and determine whether its role is associated with the AMPK/SIRT1 pathway.

RESULTS

The results revealed that IL-27 exacerbated systemic inflammation and liver damage in AHI mice by promoting M1 macrophage polarization, thereby increasing pro-inflammatory phenotype macrophages (M1). This further exacerbated the inflammatory response and pyroptosis in vivo and in vitro. Additionally, IL-27 down-regulated p-AMPK and SIRT1 protein expression while overexpressing macrophage inflammatory mediators including IL-1β/6 and TNFα. Furthermore, IL-27 promoted increased RAGE and caspase-11 protein expression, aggravating macrophage pyroptosis. Employing CC to block the AMPK pathway further aggravated M1 macrophage polarization and pyroptosis in vitro and in vivo, ultimately worsening liver injury.

CONCLUSIONS

Here, IL-27 aggravates AHI by promoting macrophage M1 polarization to induce caspase-11-mediated pyroptosis in vitro and in vivo, which may be linked to the AMPK/SIRT1 signaling pathway.

Organellophagy regulates cell death:A potential therapeutic target for inflammatory diseases

BACKGROUND

Dysregulated alterations in organelle structure and function have a significant connection with cell death, as well as the occurrence and development of inflammatory diseases. Maintaining cell viability and inhibiting the release of inflammatory cytokines are essential measures to treat inflammatory diseases. Recently, many studies have showed that autophagy selectively targets dysfunctional organelles, thereby sustaining the functional stability of organelles, alleviating the release of multiple cytokines, and maintaining organismal homeostasis. Organellophagy dysfunction is critically engaged in different kinds of cell death and inflammatory diseases.

AIM OF REVIEW

We summarized the current knowledge of organellophagy (e.g., mitophagy, reticulophagy, golgiphagy, lysophagy, pexophagy, nucleophagy, and ribophagy) and the underlying mechanisms by which organellophagy regulates cell death.

KEY SCIENTIFIC CONCEPTS OF REVIEW

We outlined the potential role of organellophagy in the modulation of cell fate during the inflammatory response to develop an intervention strategy for the organelle quality control in inflammatory diseases.

Luteolin modulates liver macrophage subtype polarization and play protective role in sepsis induced acute hepatic injury

BACKGROUND

Luteolin has an anti-inflammatory effect, but the mechanism has not been elucidated in sepsis-induced acute hepatic injury (AHI). The purpose of this study was to investigate the effects and potential mechanisms of luteolin on sepsis-induced AHI.

METHODS

In this study, we utilized both wild-type (WT) mice and Toll-like receptor 4 (TLR4)-deficient (TLR4-/-) mice alongside RAW264.7 cells. We constructed a CLP-induced AHI mouse model to study the effects of luteolin on liver inflammation, survival and liver macrophage subtypes in mice. In addition, we extracted mouse serum, mouse bone marrow-derived macrophages (BMDMs) and liver tissue and analysed the effects of luteolin on macrophage polarization subtypes and downstream inflammatory cytokines by flow cytometry, ELISA, Western blotting (WB) and qPCR. To further verify the effect of luteolin on macrophage polarization and explore the possible potential mechanism, we used a CLP-induced AHI mouse model and LPS-stimulated RAW 264.7 macrophages to assess the effect of luteolin on macrophage polarization; the expression of TNF-α and IL-10 in the cell culture supernatant; and the expression of iNOS, ARG-1, NF-κB (P65), p-P65 and MyD88 by flow cytometry, ELISA, immunohistochemistry and Western blotting.

RESULTS

We found that luteolin reduced liver injury and inflammatory response and improved the survival rate of mice. Luteolin modulated the macrophage subtype proportion, promoted the change of macrophages from a proinflammatory M1 phenotype to an anti-inflammatory M2 phenotype, and reduced the inflammatory response both in vivo and in vitro. Moreover, luteolin reduced the expression of NF-κB (p-P65), TLR4 and MyD88. By integrating the predictions from network pharmacology with the in vitro and in vivo experimental results, it was determined that the mechanism by which luteolin alleviates sepsis-induced acute hepatic injury is closely related to the TLR4/MyD88/NF-κB pathway.

CONCLUSIONS

The results of this study suggest that luteolin helps alleviate liver injury, reduces the expression of proinflammatory cytokines and promotes the expression of anti-inflammatory factors in sepsis-induced acute hepatic injury. This effect may be related to the regulation of macrophage polarization by luteolin through the TLR4/MyD88/NF-κB signalling pathway.

Protective effects of berberine on MASLD: regulation of glucose and lipid metabolism through PI3K/Akt and STING pathways

This study is aimed at exploring the therapeutic potential of berberine (BBR) in mitigating metabolic dysfunction-associated steatotic liver disease (MASLD) and at elucidating its mechanisms of action, with a focus on the modulation of glucose and lipid metabolism via the PI3K/Akt and STING signaling pathways. Male C57BL/6 J mice were fed a high-fat diet (HFD) to induce MASLD and subsequently treated with BBR or metformin. HepG2 cells were cultured in vitro, and palmitic acid (PA) was used to construct the cell model. Comprehensive analyses, including network pharmacology, transcriptome sequencing, and Western blotting, were conducted to identify critical pathways and molecular targets. Biochemical, histological, and molecular assays were performed to evaluate metabolic and inflammatory responses. BBR significantly attenuated HFD-induced hepatic steatosis, inflammation, and glucose intolerance. It effectively reduced lipid accumulation, enhanced insulin sensitivity, and modulated the expression of genes involved in lipid metabolism. Network pharmacology and transcriptome analysis highlighted the involvement of the PI3K/Akt and STING pathways. BBR activated PI3K/Akt signaling while suppressing the STING pathway, thereby reducing lipid accumulation in both in vivo and in vitro models. The inhibition of AKT negated the beneficial effects of BBR, underscoring the pivotal role of PI3K/Akt in regulating STING signaling. BBR ameliorates MASLD by activating the PI3K/Akt pathway and inhibiting the STING pathway, leading to improved glucose and lipid metabolism. These findings position BBR as a promising therapeutic candidate for the treatment of MASLD.

Mitochondrial DNA in Exercise-Mediated Innate Immune Responses

Mitochondria are considered as "the plant of power" with cells for a long time. However, recent researches suggest that mitochondria also take part in innate immune response to a great extent. Remarkably, mtDNA was reported to have immunnostimulatory potential in 2004. Since then, there has been rapid growth in understanding the role of mtDNA in innate immune. The mtDNA is released into cytosol, extracellular environment, or circulating blood through BAK/BAX pore, mPTP, and GSDMD pore upon mitochondrial damage, where it is recognized by PRRs including TLR9, cGAS, and NLRP3, thereby triggering innate immune response. On the other hand, regular exercise has been recognized as an effective intervention strategy for innate immune response. Some studies show that chronic moderate-intensity endurance exercise, resistance training, HIIT, and moderate-intensity acute exercise enhance mitochondrial function by promoting mtDNA transcription and replication, thus blunting the abnormal release of mtDNA and excessive innate immune response. On the contrary, high-intensity acute exercise elicits the opposite effect. Nevertheless, only a very small body of research by far has been performed to illustrate the impact of exercise on mtDNA-driven innate immune response, and an overall review is lacking. In light of these, we summarize the current knowledge on the mechanism mediating the release of mtDNA, the role of mtDNA in innate immune response and the influence of exercise on mtDNA leakage, hoping to pave the way to investigate new diagnostic and therapeutic approaches for immunopathies.

The conflicting role highlights the complexity of GSDMs in cancer

Gasdermins (GSDMs) are an important family of proteins that have received extensive attention in tumor research in recent years. They directly induce tumor cell death by mediating pyroptosis and also regulate the recognition and clearance of tumor cells by the immune system by affecting the microenvironment. Therefore, it is of great significance to investigate the role of GSDMs in tumor development and tumor microenvironment. It can not only reveal new mechanisms of cancer development, but also provide theoretical basis for the development of novel anti-tumor therapeutic strategies. This literature review aims to systematically summarize the dual roles of GSDMs in tumor development and their interactions with the tumor microenvironment, and to focus on the importance of GSDM-mediated pyroptosis in anti-cancer therapy, with a view to providing guidance for future research directions.

Ta4C3 MXene Slows Progression of Fatty Liver Disease through Its Anti-Inflammatory and ROS-Scavenging Effects

Treating metabolic dysfunction-associated fatty liver disease (MAFLD) and reducing the occurrence of MAFLD-associated liver cancer remain challenging. Two-dimensional (2D) tantalum carbide (Ta4C3) MXene nanozymes (MXenzymes) exhibit antioxidant and anti-inflammatory activities and have thus attracted considerable attention in the fields of oncology and engineering. However, the potential mechanism of action and bioactive properties of Ta4C3 in MAFLD remain uncertain. In our study, Ta4C3 not only inhibited lipid accumulation and disrupted lipid metabolism in hepatocytes but also reduced cell death caused by fatty acids by decreasing intracellular reactive oxygen species (ROS) levels, which significantly promoted the polarization of M1 macrophages to M2 macrophages by alleviating oxidative stress and further suppressing inflammatory factor expression. In mice fed a methionine-choline-deficient (MCD) diet, Ta4C3 reduced lipid accumulation, the infiltration of inflammatory cells, and liver cell apoptosis by modulating the cellular microenvironment through its anti-inflammatory and antioxidant properties. Therefore, Ta4C3 can be used as a multifunctional bioactive material to alleviate hepatic steatosis and inflammation in individuals with MAFLD/metabolic dysfunction-associated steatohepatitis (MASH) because of its robust antioxidant and anti-inflammatory effects.

Dietary phytosterol supplementation mitigates renal fibrosis via activating mitophagy and modulating the gut microbiota

Chronic kidney disease (CKD) poses a significant global health challenge, primarily driven by renal fibrosis, with limited treatment options. Addressing this condition necessitates either targeted medical treatments or dietary interventions. Phytosterols (PS) are cholesterol-like bioactive compounds in various plant-based foods with antioxidant and anti-inflammatory effects. A CKD mouse model was established using folic acid (FA) and treated with dietary supplements of two PS, stigmasterol (Stig) and β-sitosterol (β-Sito). The effects and mechanisms of PS were investigated through biochemical indices, pathology, transcriptomics, and 16S rDNA sequencing. The results indicated that high-dose PS are more effective than low-dose PS and Losartan potassium (LP) in reducing renal fibrosis, restoring function, and modulating oxidative stress and inflammation, with no significant differences between high-dose Stig and β-Sito treatments. Gene Ontology (GO) enrichment analysis revealed that PS were significantly enriched in pathways related to the mitochondrial outer membrane, ubiquitin-protein ligase binding, and other cellular components and molecular processes. PS reduced the expression of TGF-β/Smad and cGAS/Sting1/TBK1 and activated PINK1/Parkin pathway proteins, thereby mitigating renal fibrosis in mice. CKD is often associated with imbalanced gut microbiota and compromised intestinal barriers. Our observations indicated that PS restored the intestinal barrier, altered the composition of the gut microbiota, and improved renal function in CKD mice. The present findings indicate that both Stig and β-Sito activate mitophagy via the PINK1/Parkin pathway and modulate the gut microbiota, thereby alleviating renal fibrosis. The findings provide solid and significant implications for developing effective application of PS supplementation in the management of CKD, presenting novel concepts and approaches for research and clinical treatment.

Histone lactylation stimulated upregulation of PSMD14 alleviates neuron PANoptosis through deubiquitinating PKM2 to activate PINK1-mediated mitophagy after traumatic brain injury

Alleviating the multiple types of programmed neuronal death caused by mechanical injury has been an impetus for designing neuro-therapeutical approaches after traumatic brain injury (TBI). The aim of this study was to elucidate the potential role of PSMD14 (proteasome 26S subunit, non-ATPase 14) in neuron death and the specific mechanism through which it improves prognosis of TBI patients. Here, we identified differential expression of the PSMD14 protein between the controlled cortical impact (CCI) and sham mouse groups by LC-MS proteomic analysis and found that PSMD14 was significantly upregulated in neurons after brain injury by qPCR and western blot. PSMD14 suppressed stretch-induced neuron PANoptosis and improved motor ability and learning performance after CCI in vivo. Mechanistically, PSMD14 improved PINK1 phosphorylation levels at Thr257 and activated PINK1-mediated mitophagy by deubiquitinating PKM/PKM2 (pyruvate kinase M1/2) to maintain PKM protein stability. PSMD14-induced mitophagy promoted mitochondrial homeostasis to reduced ROS production, and ultimately inhibited the neuron PANoptosis. The upregulation of neuronal PSMD14 after TBI was due to the increase of histone lactation modification level and lactate treatment alleviated neuron PANoptosis via increasing PSMD14 expression. Our findings suggest that PSMD14 could be a potential therapeutic approach for improving the prognosis of TBI patients.Abbreviations: CCI: controlled cortical impact; CQ: chloroquine; DUBs: deubiquitinating enzymes; H3K18la: H3 lysine 18 lactylation; IB: immunoblot; IHC: immunohistochemistry; IP: immunoprecipitation; MLKL: mixed lineage kinase domain like pseudokinase; PI3K: phosphoinositide 3-kinase; PINK1: PTEN induced kinase 1; PKM/PKM2: pyruvate kinase M1/2; PSMD14: proteasome 26S subunit, non-ATPase 14; ROS: reactive oxygen species; RIPK1: receptor interacting serine/threonine kinase 1; RIPK3: receptor interacting serine/threonine kinase 3; TBI: traumatic brain injury.

HCAR2 Modulates the Crosstalk between Mammary Epithelial Cells and Macrophages to Mitigate Staphylococcus aureus Infection in the Mouse Mammary Gland

Staphylococcus aureus (S. aureus) is a major zoonotic pathogen, with mammary gland infections contributing to mastitis, a condition that poses significant health risks to lactating women and adversely affects the dairy industry. Therefore, understanding the immune mechanisms underlying mammary infections caused by S. aureus is essential for developing targeted therapeutic strategies against mastitis. This study identified hydroxycarboxylic acid receptor 2 (HCAR2) as a potential regulator of S. aureus infection in mammary glands. It is demonstrated that HCAR2 deficiency exacerbates the inflammatory response and disrupts the blood-milk barrier in the mammary gland during S. aureus infection, with NLRP3 inflammasome-mediated pyroptosis playing a central role. Activation of HCAR2, on the other hand, suppressed CMPK2 expression, thereby mitigating mitochondrial damage and pyroptosis in mouse mammary epithelial cells (mMECs) induced by S. aureus. Additionally, mitochondrial DNA (mtDNA) released from S. aureus-infected mMECs activates the cGAS/STING signaling pathway in macrophages, impairing their bactericidal activity. In conclusion, this study highlights the critical role of HCAR2 in S. aureus infection of the mammary gland and provides a theoretical basis for identifying potential therapeutic targets for such infections.

Heavy mechanical force decelerates orthodontic tooth movement via Piezo1-induced mitochondrial calcium down-regulation

Orthodontic tooth movement (OTM) depends on periodontal ligament cells (PDLCs), which sense biomechanical stimuli and initiate alveolar bone remodeling. Light (optimal) forces accelerate OTM, whereas heavy forces decelerate it. However, the mechanisms by which PDLCs sense biomechanical stimuli and affect osteoclastic activities under different mechanical forces (MFs) remain unclear. This study demonstrates that mechanosensitive ion channel Piezo1-mediated Ca2+ signal conversion is crucial for sensing and delivering biomechanical signals in PDLCs under heavy-force conditions. Heavy MF up-regulated Piezo1 in PDLCs, reducing mitochondrial Ca2+ influx by inhibiting ITPR3 expression in mitochondria-associated membranes. Decreased mitochondrial calcium uptake led to reduced cytoplasmic release of mitochondrial DNA and inhibited the activation of the cGAS‒STING signaling cascade, subsequently inhibiting monocyte-to-osteoclast differentiation. Inhibition of Piezo1 or up-regulation of STING expression under heavy MF conditions significantly increased osteoclast activity and accelerated OTM. These findings suggest that heavy MF-induced Piezo1 expression in PDLCs is closely related to the control of osteoclast activity during OTM and plays an essential role in alveolar bone remodeling. This mechanism may be a potential therapeutic target for accelerating OTM.

Cytosolic mtDNA-cGAS-STING axis mediates melanocytes pyroptosis to promote CD8+ T-cell activation in vitiligo

BACKGROUND

The cGAS-STING axis, a DNA sensor pathway, has recently emerged as a key hub in sensing stress signals and initiating the immune cascade in several diseases. However, its role in the pathogenesis of vitiligo remains unclear.

OBJECTIVE

To explore the pathogenic role of the cGAS-STING axis in linking oxidative stress and CD8+ T-cell-mediated anti-melanocytic immunity in vitiligo.

METHODS

The expression status of the cGAS-STING axis and cytosolic mtDNA were evaluated in the oxidatively stressed epidermal cells and vitiligo perilesional skin, respectively. Then, we investigated the activation of cGAS-STING axis in mtDNA-treated melanocytes, and the influence of cGAS or STING silencing on mtDNA-induced melanocytes pyroptosis. Finally, the paracrine effects of melanocytes pyroptosis on CD8+ T cell activation were explored.

RESULTS

We initially demonstrated that the cGAS-STING axis in melanocytes was highly susceptible to oxidative stress and activated in the vitiliginous melanocytes of perilesional skin, accompanied by enhanced cytosolic mtDNA accumulation. Our mechanistic in vitro experiments confirmed that oxidative stress-induced mitochondrial damage in epidermal cells led to cytosolic mtDNA accumulation, which served as a trigger in activating the cGAS-STING axis in melanocytes. Furthermore, the cytosolic mtDNA-cGAS-STING axis was verified to mediate melanocytes pyroptosis. More importantly, we found that IL-1β and IL-18 produced by pyroptotic melanocytes promoted the activation of CD8+ T cells from patients with vitiligo.

CONCLUSION

The present study confirmed that the cytosolic mtDNA-cGAS-STING axis of melanocytes played an important role in oxidative stress-triggered CD8+ T-cell response, providing novel insights into mechanisms underlying vitiligo onset.

Liver-Secreted Extracellular Vesicles Promote Cirrhosis-Associated Skeletal Muscle Injury Through mtDNA-cGAS/STING Axis

Skeletal muscle atrophy (sarcopenia) is a serious complication of liver cirrhosis, and chronic muscle inflammation plays a pivotal role in its pathologenesis. However, the detailed mechanism through which injured liver tissues mediate skeletal muscle inflammatory injury remains elusive. Here, it is reported that injured hepatocytes might secrete mtDNA-enriched extracellular vesicles (EVs) to trigger skeletal muscle inflammation by activating the cGAS-STING pathway. Briefly, injured liver secreted increased amounts of EVs into circulation, which are then engulfed primarily by macrophages in skeletal muscle and subsequently induce cGAS-STING signaling and its-mediated inflammatory response in muscles. In contrast, suppression of hepatic EV secretion or STING signaling significantly alleviated cirrhosis-induced skeletal muscle inflammation and muscle atrophy in vivo. Circulating EVs from cirrhotic patients showed higher levels of mtDNA, and the levels of EV-mtDNA positively correlated with the severity of liver injury. In injured hepatocytes, mitochondrial damage promoted the release of cytosolic mtDNA and the subsequent secretion of mtDNA-enriched EVs. This study reveals that injured hepatocyte-derived EVs induce skeletal muscle inflammation via the mtDNA‒STING axis, while targeted blockade of liver EV secretion or STING signaling represents a potential therapeutic approach for preventing cirrhosis-associated skeletal muscle atrophy.

Bidirectional regulation of the cyclic guanosine monophosphate-adenosine monophosphate synthase-stimulator of interferon gene pathway and its impact on hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) ranks as the fourth leading cause of cancer-related deaths in China, and the treatment options are limited. The cyclic guanosine monophosphate-adenosine monophosphate synthase (cGAS) activates the stimulator of interferon gene (STING) signaling pathway as a crucial immune response pathway in the cytoplasm, which detects cytoplasmic DNA to regulate innate and adaptive immune responses. As a potential therapeutic target, cGAS-STING pathway markedly inhibits tumor cell proliferation and metastasis, with its activation being particularly relevant in HCC. However, prolonged pathway activation may lead to an immunosuppressive tumor microenvironment, which fostering the invasion or metastasis of liver tumor cells.

AIM

To investigate the dual-regulation mechanism of cGAS-STING in HCC.

METHODS

This review was conducted according to the PRISMA guidelines. The study conducted a comprehensive search for articles related to HCC on PubMed and Web of Science databases. Through rigorous screening and meticulous analysis of the retrieved literature, the research aimed to summarize and elucidate the impact of the cGAS-STING pathway on HCC tumors.

RESULTS

All authors collaboratively selected studies for inclusion, extracted data, and the initial search of online databases yielded 1445 studies. After removing duplicates, the remaining 964 records were screened. Ultimately, 55 articles met the inclusion criteria and were included in this review.

CONCLUSION

Acute inflammation can have a few inhibitory effects on cancer, while chronic inflammation generally promotes its progression. Extended cGAS-STING pathway activation will result in a suppressive tumor microenvironment.

Mitochondrial DNA leakage: underlying mechanisms and therapeutic implications in neurological disorders

Mitochondrial dysfunction is a pivotal instigator of neuroinflammation, with mitochondrial DNA (mtDNA) leakage as a critical intermediary. This review delineates the intricate pathways leading to mtDNA release, which include membrane permeabilization, vesicular trafficking, disruption of homeostatic regulation, and abnormalities in mitochondrial dynamics. The escaped mtDNA activates cytosolic DNA sensors, especially cyclic gmp-amp synthase (cGAS) signalling and inflammasome, initiating neuroinflammatory cascades via pathways, exacerbating a spectrum of neurological pathologies. The therapeutic promise of targeting mtDNA leakage is discussed in detail, underscoring the necessity for a multifaceted strategy that encompasses the preservation of mtDNA homeostasis, prevention of membrane leakage, reestablishment of mitochondrial dynamics, and inhibition the activation of cytosolic DNA sensors. Advancing our understanding of the complex interplay between mtDNA leakage and neuroinflammation is imperative for developing precision therapeutic interventions for neurological disorders.

Liver diseases: epidemiology, causes, trends and predictions

As a highly complex organ with digestive, endocrine, and immune-regulatory functions, the liver is pivotal in maintaining physiological homeostasis through its roles in metabolism, detoxification, and immune response. Various factors including viruses, alcohol, metabolites, toxins, and other pathogenic agents can compromise liver function, leading to acute or chronic injury that may progress to end-stage liver diseases. While sharing common features, liver diseases exhibit distinct pathophysiological, clinical, and therapeutic profiles. Currently, liver diseases contribute to approximately 2 million deaths globally each year, imposing significant economic and social burdens worldwide. However, there is no cure for many kinds of liver diseases, partly due to a lack of thorough understanding of the development of these liver diseases. Therefore, this review provides a comprehensive examination of the epidemiology and characteristics of liver diseases, covering a spectrum from acute and chronic conditions to end-stage manifestations. We also highlight the multifaceted mechanisms underlying the initiation and progression of liver diseases, spanning molecular and cellular levels to organ networks. Additionally, this review offers updates on innovative diagnostic techniques, current treatments, and potential therapeutic targets presently under clinical evaluation. Recent advances in understanding the pathogenesis of liver diseases hold critical implications and translational value for the development of novel therapeutic strategies.

Artemether Ameliorates Non-Alcoholic Steatohepatitis by Restraining Cross-Talk Between Lipotoxicity-Induced Hepatic Hepatocytes and Macrophages

Non-alcoholic steatohepatitis (NASH) has no effective treatment drug. Our previous study initially found that artemether (Art) treatment significantly attenuates NSAH by regulating liver lipid metabolism. This study further elucidates new mechanisms of Art in improving liver inflammation and provides evidence for drug repurposing. Herein, we utilized HFHF diet-induced animal model and macrophage models to detect the mechanisms of Art in NASH. We confirmed that Art significantly reduced hepatic steatosis, injury, and fibrosis in a high-fat high-fructose (HFHF) diet-induced animal model. Art significantly suppressed the activation of inflammatory macrophages and secretion of pro-inflammatory cytokine (IL-1β) by reducing serum double-stranded DNA (dsDNA) levels and triggering the AIM2/Caspase-1/GSDMD signaling in vivo. dsDNA-induced Caspase-1 and PI-positive cells pyroptosis, AIM2 inflammasome activation, IL-1β, and IL-18 secretion increase were inhibited by Art in vitro. Furthermore, we found Art effectively suppressed mitochondrial DNA (mtDNA), a typical form of dsDNA, released from free fatty acid (FFA)-stressed hepatocytes, which further inhibited AIM2 inflammasome mediated-pyroptosis through decreasing the cleavage of Caspase-1/GSDMD/IL-1β. Moreover, inhibition of the AIM2 gene partly reversed the inhibitory effect of Art on macrophage pyroptosis. Impaired mitochondrial structure and function were confirmed in FFA-stressed hepatocytes and the HFHF-diet-induced NASH mouse model, which was reversed by Art treatment. The present study provides evidence for Art as a potential anti-pyroptosis therapeutic agent for NASH treatment.

Mitochondrial DNA-activated cGAS-STING pathway in cancer: Mechanisms and therapeutic implications

Mitochondrial DNA (mtDNA), a circular double-stranded DNA located within mitochondria, plays a pivotal role in mitochondrial-induced innate immunity, particularly via the cyclic GMP-AMP synthase (cGAS)-STING pathway, which recognizes double-stranded DNA and is crucial for pathogen resistance. Recent studies elucidate the interplay among mtDNA, the cGAS-STING pathway, and neutrophil extracellular traps (NETs) in the context of cancer. mtDNA uptake by recipient cells activates the cGAS-STING pathway, while mtDNA leakage reciprocally regulates NET release, amplifying inflammation and promoting NETosis, a mechanism of tumor cell death. Autophagy modulates these processes by clearing damaged mitochondria and degrading cGAS, thus preventing mtDNA recognition. Tumor microenvironmental factors, such as metabolic reprogramming and lipid accumulation, induce mitochondrial stress, ROS production, and further mtDNA leakage. This review explores strategies in cancer drug development that leverage mtDNA leakage to activate the cGAS-STING pathway, potentially converting 'cold tumors' into 'hot tumors,' while discussing advancements in targeted therapies and proposing new research methodologies.

The protective role of baicalin regulation of autophagy in cancers

Autophagy is a conservative process of self degradation, in which abnormal organelles, proteins and other macromolecules are encapsulated and transferred to lysosomes for subsequent degradation. It maintains the intracellular balance, and responds to cellular conditions such as hunger or stress. To date, there are mainly three types of autophagy: macroautophagy, microautophagy and chaperone-mediated autophagy. Autophagy plays a key role in regulating multiple physiological and pathological processes, such as cell metabolism, development, energy homeostasis, cell death and hunger adaptation, and so on. Increasing evidence indicates that autophagy dysfunction participates in many kinds of cancers, such as liver cancer, pancreatic cancer, prostate cancer, and so on. However, the relevant mechanisms are not yet fully understood. Baicalin is a natural flavonoid compound extracted from the traditional Chinese medicine Scutellaria baicalensis. The research has shown that after oral or intravenous administration of baicalin, it is delivered to various organs through the systemic circulation, with the highest volume in the kidneys and lungs. More and more evidence suggests that baicalin has antioxidant, anticancer, anti-inflammatory, anti-apoptotic, immunomodulatory and antiviral effects. Therefore, baicalin plays an important role in various diseases, such as cancers, lung diseases, liver diseases, cardiovascular diseases, ans so on. However, the relevant mechanisms have not yet been fully clear. Recently, increasing evidence indicates that baicalin participates in different cancer by regulating autophagy. Herein, we reviewed the current knowledge about the role and mechanism of baicalin regulation of autophagy in multiple types of cancers to lay the theoretical foundation for future related researches.

Sulforaphane regulation autophagy-mediated pyroptosis in autoimmune hepatitis via AMPK/mTOR pathway

Autoimmune hepatitis (AIH) is a liver disease marked by inflammation of unknown origin. If untreated, it can progress to cirrhosis or liver failure, posing a significant health risk. Currently, effective drug therapies are lacking in clinical practice. Sulforaphane (SFN), a natural anti-inflammatory and antioxidant compound found in various cruciferous vegetables, alleviate pyroptosis and improve impaired autophagic flux, both of which contribute to AIH progression. However, whether SFN modulates autophagic flux and pyroptosis in S100-induced EAH through the AMPK/mTOR pathway remains unclear. Therefore, this study aims to investigate whether SFN can regulate AIH and elucidate its potential mechanisms of action. In this study, experimental AIH (EAH) was induced in male C57BL/6 J mice through intraperitoneal (i.p.) injection of S100. SFN was administered intraperitoneally every other day. After 28 days, the mice were euthanized, and their livers and serum were collected for histological and biochemical analyses. AML12 cells were used for the in vitro studies. The results showed that SFN mitigated pyroptosis by inhibiting the NLRP3 inflammasome and improving autophagic flux, which alleviates S100-induced EAH. Conversely, the autophagy inhibitor 3-MA negated the protective effects of SFN against inflammasome-mediated pyroptosis. Furthermore, SFN activated the AMPK/mTOR signaling pathway, offering protection against S100-induced EAH. Selective inhibition of AMPK suppressed the improvement in autophagic flux and protected against SFN-induced pyroptosis. Overall, SFN significantly ameliorates S100-induced EAH by enhancing autophagic flux and mitigating pyroptosis through activation of the AMPK/mTOR signaling pathway.

A novel small molecule NJH-13 induces pyroptosis via the Ca2+ driven AKT-FOXO1-GSDME signaling pathway in NSCLC by targeting TRPV5

INTRODUCTION

Pyroptosis represents a mode of programmed necrotic cell death (PCD), mediated by members of gasdermin family (GSDMs), such as GSDME. It is emerging as a promising approach for combating cancer. Notably, GSDME is the key modulator for the switch between apoptosis and pyroptosis in cells. However, GSDME is often downregulated in many malignancies, including lung adenocarcinoma.

OBJECTIVE

To identify novel pyroptosis inducers in non-small cell lung cancer (NSCLC) and dissect the underlying mechanism.

METHODS

Pyroptosis was examined by live cell imaging, PI/Hoechst/Annexin V staining, LDH release assay, ELISA, and western blot assays. DARTS, CETSA, molecular docking was used to identify the target of NJH-13. RNA-seq, qPCR, chromatin immunoprecipitation (ChIP), dual luciferase assays were used elucidate the mechanism.

RESULTS

In this study, NJH-13, an N-containing heterocycle, was screened out and identified to possess the ability to activate GSDME, consequently triggering pyroptosis in NSCLC cells. By using the DARTS strategy, transient receptor potential cation channel subfamily V member 5 (TRPV5) was identified as a potential target of NJH-13. NJH-13 increased intracellular calcium level and triggered oxidative stress, both of which are critical events leading to pyroptosis mediated by GSDME. Mechanistically, NJH-13 enhanced the transcription of GSDME via the protein kinase B (AKT)/forkhead box transcription factor O1 (FOXO1) signaling pathway. ChIP revealed that FOXO1 bound directly to the promoter region of GSDME, thus triggering the GSDME-mediated pyroptosis. Pharmacological and genetic activation of AKT or inhibition of FOXO1 partially rescued NJH-13-induced pyroptotic cell death. Moreover, NJH-13 treatment suppressed tumor growth in vivo.

CONCLUSION

Taken together, our results revealed that TRPV5 is a distinctive target for manipulating pyroptosis and provided evidence that NJH-13 functions as a potential anti-cancer agent capable of triggering pyroptosis in NSCLC cells.

Ferroptosis and pyroptosis are connected through autophagy: a new perspective of overcoming drug resistance

Drug resistance is a common challenge in clinical tumor treatment. A reduction in drug sensitivity of tumor cells is often accompanied by an increase in autophagy levels, leading to autophagy-related resistance. The effectiveness of combining chemotherapy drugs with autophagy inducers/inhibitors has been widely confirmed, but the mechanisms are still unclear. Ferroptosis and pyroptosis can be affected by various types of autophagy. Therefore, ferroptosis and pyroptosis have crosstalk via autophagy, potentially leading to a switch in cell death types under certain conditions. As two forms of inflammatory programmed cell death, ferroptosis and pyroptosis have different effects on inflammation, and the cGAS-STING signaling pathway is also involved. Therefore, it also plays an important role in the progression of some chronic inflammatory diseases. This review discusses the relationship between autophagy, ferroptosis and pyroptosis, and attempts to uncover the reasons behind the evasion of tumor cell death and the nature of drug resistance.

Decreased STING predicts adverse efficacy in bortezomib regimens and poor survival in multiple myeloma

PURPOSE

STING (stimulator of interferon genes) is involved in viral and bacterial defense through interferon pathway and innate immunity. Increased susceptibility to infection is a common manifestation of multiple myeloma (MM). Thus, we aimed to explore the clinical significance and possible mechanism of STING in MM.

MATERIALS AND METHODS

Immunohistochemistry and qPCR were used to detect STING expression in the bone marrow of MM patients, and flow cytometry was used to detect the amount of intracellular STING. All data were analyzed with clinical characteristics.

RESULTS

STING expression was remarkably reduced in MM tissues compared to normal tissues and was not associated with stage. Multivariate analysis identified STING as an independent prognostic factor in MM patients (P = 0.001). In the bortezomib-containing regimens, patients with low STING expression were more difficult to achieve remission. A model incorporating STING and m-SMART significantly improved the predictive accuracy of overall survival in bortezomib regimens (AUC, 0.511 to 0.630, P = 0.044). Bortezomib efficacy has been reported to correlate with activated immunity, but the low expression group manifested as immune apathy. Although baseline characteristics showed intergroup differences in infection, the low expression group had an increased proportion of bacterial infections (1.7-fold) and a prolonged duration of antibiotic/antifungal medication (3.55 additional days); these patients were accompanied by a decreased neutrophil-to-lymphocyte ratio (NLR) and rarely activated neutrophils and leukocytes. The intracellular STING ratio was also defective in neutrophil-dominated leukocytes.

CONCLUSION

Our study revealed that STING had a strong association with bortezomib and could serve as a potential target for immunotherapy in multiple myeloma.