Significance: Endometriosis is a highly prevalent proinflammatory disease without reliable diagnostic biomarkers and cannot be cured by nowadays’ medical treatments. Herein, we identified that extracellular vesicle (EV)-associated VEGF-C, secreted by proinflammatory cytokine-stimulated endometriotic stromal cells, is a critical modulator for endometriosis progression by promoting lymphangiogenesis. Invaded lymphatic vessels may serve as a canal for the infiltration of immune cells, which further enhances the inflammatory status in the endometriotic microenvironment and produces more EV-VEGF-C. The elevated circulating EV-VEGF-C is a sensitive and reliable biomarker for detecting endometriosis. These data advance our understanding of the pathophysiology of endometriosis and suggest VEGF-C can be a noninvasive diagnostic biomarker and a potential therapeutic target for endometriosis.

Monocytes are a major population of circulating immune cells that play a crucial role in producing pro-inflammatory cytokines in the body. The actions of monocytes are known to be influenced by the combinations and concentrations of certain fatty acids (FAs) in blood and dietary fats. However, systemic comparisons of the effects of FAs on cytokine secretion by monocytes have not be performed. In this study, we compared how six saturated FAs (SFAs), two monounsaturated FAs (MUFAs), and seven polyunsaturated FAs (PUFAs) modulate human THP-1 monocyte secretion of TNF, IL-1β, and IL-6 in the absence or presence of lipopolysaccharide. SFAs generally stimulated resting THP-1 cells to secrete pro-inflammatory cytokines, with stearic acid being the most potent species. In contrast, MUFAs and PUFAs inhibited lipopolysaccharide-induced secretion of pro-inflammatory cytokines. Interestingly, the inhibitory potentials of MUFAs and PUFAs followed U-shaped (TNF and IL-1β) or inverted U-shaped (IL-6) dose–response curves. Among the MUFAs and PUFAs that were analyzed, docosahexaenoic acid (C22:6 n-3) exhibited the largest number of double bonds and was found to be the most potent anti-inflammatory compound. Together, our findings reveal that the chemical compositions and concentrations of dietary FAs are key factors in the intricate regulation of monocyte-mediated inflammation.

Introduction: Insulin, the key hormone for glucose regulation, has garnered attention for its role as an immune modulator. Impaired insulin signaling in the central nervous system is linked to neuroinflammation and neurodegenerative diseases. Microglia, the resident macrophage-like immune cells in the brain, are key regulators of neuroinflammation. However, the mechanisms by which insulin influences microglial immune responses remain relatively unknown. Methods: This study aimed to assess the effects of post-treatment with insulin [30 minutes after lipopolysaccharide (LPS) exposure] on LPS-induced inflammatory responses in BV2 microglial cells. Results: Post-treatment with insulin potentiated LPS-induced production of nitric oxide and pro-inflammatory cytokines, such as TNF and IL-6, through activation of the Akt/NF-κB pathway. Insulin also enhanced the ability of BV2 cells to phagocytose bacteria particles and β-amyloid fibrils. Conversely, insulin inhibited activation of NADPH oxidase and reduced intracellular levels of reactive oxygen species in LPS-treated BV2 cells. Conclusion: Insulin enhances microglial immune competence when challenged by endotoxins but mitigates oxidative stress in these cells.

Metastasis is the main cause of death in many cancers including colorectal cancer (CRC); however, the underlying mechanisms responsible for metastatic progression remain largely unknown. We found that nuclear TYRO3 receptor tyrosine kinase is a strong predictor of poor overall survival in patients with CRC. The metastasis-promoting function of nuclear TYRO3 requires its kinase activity and matrix metalloproteinase–2 (MMP-2)–mediated cleavage but is independent of ligand binding. Using proteomic analysis, we identified bromodomain-containing protein 3 (BRD3), an acetyl-lysine reading epigenetic regulator, as one of nuclear TYRO3’s substrates. Chromatin immunoprecipitation-sequencing data reveal that TYRO3-phosphorylated BRD3 regulates genes involved in anti-apoptosis and epithelial-mesenchymal transition. Inhibition of MMP-2 or BRD3 activity by selective inhibitors abrogates nuclear TYRO3-induced drug resistance and metastasis in organoid culture and in orthotopic mouse models. These data demonstrate that MMP-2/TYRO3/BRD3 axis promotes the metastasis of CRC, and blocking this signaling cascade is a promising approach to ameliorate CRC malignancy.

Objective: Gastric cancer with peritoneal metastasis is considered to be final stage gastric cancer. One current treatment approach for this condition is combined cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (HIPEC). However, the therapeutic mechanisms of HIPEC remain largely undescribed. Method: In order to assess the cellular effects of HIPEC in vitro, we treated AGS human gastric adenocarcinoma cells with or without 5-fluorouracil (5-Fu) at 37 °C or at 43 °C (hyperthermic temperature) for 1 h followed by incubation at 37 °C for 23 h. The impacts of hyperthermia/5-Fu on apoptosis, cell survival signals, oxidative stress, chemoresistance-related proteins and programmed death-ligand 1 (PD-L1) expression were measured. Results: Our results showed that hyperthermia potentiates 5-Fu-mediated cytotoxicity in AGS cells. Furthermore, the combination of 5-Fu and hyperthermia reduces levels of both phosphorylated STAT3 and STAT3, while increasing the levels of phosphorylated Akt and ERK. In addition, 5-Fu/hyperthermia enhances reactive oxygen species and suppresses superoxide dismutase 1. Chemoresistance-related proteins, such as multidrug resistance 1 and thymidylate synthase, are also suppressed by 5-Fu/hyperthermia. Interestingly, hyperthermia enhances 5-Fu-mediated induction of glycosylated PD-L1, but 5-Fu-mediated upregulation of PD-L1 surface expression is prevented by hyperthermia. Conclusion: Taken together, our findings provide insights that may aid in the development of novel therapeutic strategies and enhanced therapeutic efficacy of HIPEC.

Aims: Osteosarcoma is the most common primary bone malignancy among children and adolescents. We investigated whether benzamil, an amiloride analogue and sodium-calcium exchange blocker, may exhibit therapeutic potential for osteosarcoma in vitro.Methods: MG63 and U2OS cells were treated with benzamil for 24 hours. Cell viability was evaluated with the MTS/PMS assay, colony formation assay, and flow cytometry (forward/side scatter). Chromosome condensation, the terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) assay, cleavage of poly-ADP ribose polymerase (PARP) and caspase-7, and FITC annexin V/PI double staining were monitored as indicators of apoptosis. Intracellular calcium was detected by flow cytometry with Fluo-4 AM. The phosphorylation and activation of focal adhesion kinase (FAK) and signal transducer and activator of transcription 3 (STAT3) were measured by western blot. The expression levels of X-linked inhibitor of apoptosis protein (XIAP), B-cell lymphoma 2 (Bcl-2), B-cell lymphoma-extra large (Bcl-xL), SOD1, and SOD2 were also assessed by western blot. Mitochondrial status was assessed with tetramethylrhodamine, ethyl ester (TMRE), and intracellular adenosine triphosphate (ATP) was measured with BioTracker ATP-Red Live Cell Dye. Total cellular integrin levels were evaluated by western blot, and the expression of cell surface integrins was assessed using fluorescent-labelled antibodies and flow cytometry.Results: Benzamil suppressed growth of osteosarcoma cells by inducing apoptosis. Benzamil reduced the expression of cell surface integrins α5, αV, and β1 in MG63 cells, while it only reduced the expression of αV in U2OS cells. Benzamil suppressed the phosphorylation and activation of FAK and STAT3. In addition, mitochondrial function and ATP production were compromised by benzamil. The levels of anti-apoptotic proteins XIAP, Bcl-2, and Bcl-xL were reduced by benzamil. Correspondingly, benzamil potentiated cisplatin- and methotrexate-induced apoptosis in osteosarcoma cells.Conclusion: Benzamil exerts anti-osteosarcoma activity by inducing apoptosis. In terms of mechanism, benzamil appears to inhibit integrin/FAK/STAT3 signalling, which triggers mitochondrial dysfunction and ATP depletion.Cite this article: Bone Joint Res 2024;13(4):157–168.