Promotion of Lung Cancer Metastasis by SIRT2-Mediated Extracellular Protein Deacetylation

Exosomes secreted from adipose-derived stem cells inhibit M1 macrophage polarization ameliorate chronic endometritis by regulating SIRT2/NLRP3

Chronic endometritis (CE) is a key factor in adverse pregnancy outcomes such as miscarriage and infertility. Macrophages are an important immune cell type that secrete pro-inflammatory and anti-inflammatory cytokines that are essential for maintaining endometrial function. This study aimed to investigate the key mechanisms by which exosomes derived from adipose-derived mesenchymal stem cells (ADSCs) regulate macrophage polarization through the sirtuin 2 (SIRT2)/NOD-like receptor pyrin containing 3 (NLRP3) axis and exert a protective effect on CE. Exosomes were obtained from ADSCs (ADSCs-exo) using the classical ultracentrifugation method and characterized using transmission electron microscopy, nanoparticle tracking analysis, and western blotting. ADSCs-exo protective effects on CE mice and RAW 264.7 cells and its related molecular mechanisms were investigated using real-time quantitative polymerase chain reaction, western blotting, enzyme-linked immunosorbent assay, flow cytometry, immunofluorescence, immunoprecipitation, hematoxylin and eosin staining, and immunohistochemistry. ADSCs-exo significantly inhibited M1 macrophage polarization, as evidenced by a 54% reduction in tumor necrosis factor alfa (TNF-α), a 46% reduction in interleukin 1β (IL-1β), and a 36% reduction in interleukin 6 (IL-6) levels in LPS-induced RAW264.7 cells. In vivo, ADSCs-exo treatment reduced the expression of TNF-α by 50%, IL-1β by 58%, and IL-6 by 49% in the uterine tissues of CE mice. Moreover, ADSCs-exo upregulated the expression of SIRT2, promoted the deacetylation modification of NLRP3 to inhibit NLRP3 inflammasome activation, and further suppressed M1 macrophage polarization. However, these trends were reversed after SIRT2 silencing. Our experimental results demonstrate that ADSCs-exo alleviate CE by regulating the SIRT2/NLRP3 axis to inhibit M1 macrophage polarization. This provides a potential theoretical basis for the therapeutic role of stem cells in CE.

Potential role of lactylation in intrinsic immune pathways in lung cancer

Lung cancer, one of the most lethal malignancies, has seen its therapeutic strategies become a focal point of significant scientific attention. Intrinsic immune signaling pathways play crucial roles in anti-tumor immunity but face clinical application challenges despite promising preclinical outcomes. Lactylation, an emerging research focus, may influences lung cancer progression by modulating the functions of histones and non-histone proteins. Recent findings have suggested that lactylation regulates key intrinsic immune molecules, including cGAS-STING, TLR, and RIG-I, thereby impacting interferon expression. However, the precise mechanisms by which lactylation governs intrinsic immune signaling in lung cancer remain unclear. This review presents a comprehensive and systematic analysis of the relationship between lactylation and intrinsic immune signaling pathways in lung cancer and emphasizes the innovative perspective of linking lactylation-mediated epigenetic modifications with immune regulation. By thoroughly examining current research findings, this review uncovers potential regulatory mechanisms and highlights the therapeutic implications of targeting lactylation in lung cancer. Future investigations into the intricate interactions between lactylation and intrinsic immunity are anticipated to unveil novel therapeutic targets and strategies, potentially improving patient survival outcomes.

Sirtuin 2 regulates neutrophil functions through NAD+ synthesis pathway in virus infection

Neutrophils play an important role in antiviral immunity, but the underlying mechanisms remain unclear. Here, we found that SIRT2 deficiency inhibited the infiltration of neutrophils, as well as the secretion of inflammatory cytokines and the formation of neutrophil extracellular traps (NETs), ameliorating disease symptoms during acute respiratory virus infection. Mechanistically, SIRT2 deficiency upregulates quinolinic acid (QA)-producing enzyme 3-hydroxyanthranilate oxygenase (3-HAO) and leads to expression of quinolinate phosphoribosyltransferase (QPRT), which promotes the synthesis of QA for NAD+ and limits viral infection when de novo NAD+ synthesis is blocked. Tryptophan-2,3-oxygenase expressed in epithelial cells metabolizes tryptophan to produce kynurenine and 3-hydroxyaminobenzoic acid, which is a source of intracellular QA in neutrophils. Thus, our findings reveal a previously unrecognized QPRT-mediated switch in NAD+ metabolism by exploiting neutrophil-derived QA as an alternative source of replenishing intracellular NAD+ pools induced by SIRT2 to regulate neutrophil functions during virus infection, with implications for future immunotherapy approaches.

Harnessing innate immune pathways for therapeutic advancement in cancer

The innate immune pathway is receiving increasing attention in cancer therapy. This pathway is ubiquitous across various cell types, not only in innate immune cells but also in adaptive immune cells, tumor cells, and stromal cells. Agonists targeting the innate immune pathway have shown profound changes in the tumor microenvironment (TME) and improved tumor prognosis in preclinical studies. However, to date, the clinical success of drugs targeting the innate immune pathway remains limited. Interestingly, recent studies have shown that activation of the innate immune pathway can paradoxically promote tumor progression. The uncertainty surrounding the therapeutic effectiveness of targeted drugs for the innate immune pathway is a critical issue that needs immediate investigation. In this review, we observe that the role of the innate immune pathway demonstrates heterogeneity, linked to the tumor development stage, pathway status, and specific cell types. We propose that within the TME, the innate immune pathway exhibits multidimensional diversity. This diversity is fundamentally rooted in cellular heterogeneity and is manifested as a variety of signaling networks. The pro-tumor effect of innate immune pathway activation essentially reflects the suppression of classical pathways and the activation of potential pro-tumor alternative pathways. Refining our understanding of the tumor's innate immune pathway network and employing appropriate targeting strategies can enhance our ability to harness the anti-tumor potential of the innate immune pathway and ultimately bridge the gap from preclinical to clinical application.

Harnessing the innate immune system by revolutionizing macrophage-mediated cancer immunotherapy

Immunotherapy is a promising and safer alternative to conventional cancer therapies. It involves adaptive T-cell therapy, cancer vaccines, monoclonal antibodies, immune checkpoint blockade (ICB), and chimeric antigen receptor (CAR) based therapies. However, most of these modalities encounter restrictions in solid tumours owing to a dense, highly hypoxic and immune-suppressive microenvironment as well as the heterogeneity of tumour antigens. The elevated intra-tumoural pressure and mutational rates within fastgrowing solid tumours present challenges in efficient drug targeting and delivery. The tumour microenvironment is a dynamic niche infiltrated by a variety of immune cells, most of which are macrophages. Since they form a part of the innate immune system, targeting macrophages has become a plausible immunotherapeutic approach. In this review, we discuss several versatile approaches (both at pre-clinical and clinical stages) such as the direct killing of tumour-associated macrophages, reprogramming pro-tumour macrophages to anti-tumour phenotypes, inhibition of macrophage recruitment into the tumour microenvironment, novel CAR macrophages, and genetically engineered macrophages that have been devised thus far. These strategies comprise a strong and adaptable macrophage-toolkit in the ongoing fight against cancer and by understanding their significance, we may unlock the full potential of these immune cells in cancer therapy.

Identification of Autophagy-Related Targets of Berberine against Non-Small Cell Lung Cancer and Their Correlation with Immune Cell Infiltration By Combining Network Pharmacology, Molecular Docking, and Experimental Verification

OBJECTIVE

Non-small cell lung cancer (NSCLC) is the most common lung cancer type with high incidence. This study aimed to reveal the anti-NSCLC mechanisms of berberine and identify novel therapeutic targets.

METHODS

Berberine-related targets were acquired from SuperPred, SwissTargetPrediction, and GeneCards. NSCLC-re-lated targets were collected from GeneCards and DisGeNET. Differentially expressed genes (DEGs) were identified GEO database, UCSC Xena, and limma. GO and KEGG analyses were performed using clusterProfiler. Autophagy-related genes and transcriptional factors were collected from HADb and KnockTF, respectively. STRING and Cytoscape were used for PPI network analysis. Immune cell infiltration in NSCLC was assessed using CIBERSORT, and its correlation with autophagy-related targets was evaluated. Molecular docking was conducted using PyMOL and AutoDock. qRT-PCR and CCK-8 assay was used for in vitro verification.

RESULTS

Thirty intersecting targets of berberine-related targets, NSCLC-related targets, and DEGs were obtained. GO and KEGG analyses revealed that the intersecting targets were mainly implicated in oxidative stress, focal adhesion, and cell-substrate junction, as well as AGE-RAGE, relaxin, FoxO, and estrogen signaling pathways. Significantly, CAPN1, IKBKB, and SIRT2 were identified as the foremost autophagy-related targets, and 21 corresponding transcriptional factors were obtained. PPI network analysis showed that CAPN1, IKBKB, and SIRT2 interacted with 50 other genes. Fifty immune cell types, such as B cells naive, T cells CD8, T cells CD4 naive, T cells follicular helper, and monocytes, were implicated in NSCLC pathogenesis, and CAPN1, IKBKB, and SIRT2 were related to immune cells. Molecular docking revealed the favorable binding activity of berberine with CAPN1, IKBKB, and SIRT2. In vitro assays showed lower CAPN1, IKBKB, and SIRT2 expression in NSCLC cells than that in normal cells. Notably, berberine inhibited the viability and elevated CAPN1, IKBKB, and SIRT2 expression in NSCLC cells.

CONCLUSIONS

Berberine might treat NSCLC mainly by targeting CAPN1, IKBKB, and SIRT2.