Phil-Dong Moon

Background: Cytokine oncostatin M (OSM) is implicated in inflammatory conditions. The plant sterol stigmasterol (ST) is found in diverse plant foods and exerts various benefits, such as antitumor, antioxidant, and anti-inflammatory effects. However, the inhibitory mechanism of ST on OSM production in neutrophils needs to be elucidated. Methods: To evaluate the modulatory effects of ST, this investigation employed neutrophil-like differentiated (d)HL-60 cells. ELISA, real-time PCR, Western blotting, and immunofluorescence staining were conducted. dHL-60 cells were pretreated with ST (0.02 to 2 µg/mL) for 1 h, and then stimulated with GM-CSF (5 ng/mL). Results: Our results showed that addition of granulocyte–macrophage colony-stimulating factor (GM-CSF) leads to up-regulation of OSM mRNA and protein in dHL-60 cells, while pretreatment with ST reduces OSM mRNA and protein levels. Mechanistically, the highest dose (2 µg/mL) of ST significantly decreased phosphorylation of phosphatidylinositol 3-kinase, protein kinase B (Akt), and nuclear factor-κB. Conclusions: Our findings suggest that the plant sterol ST shows potential and warrants in vivo validation on OSM regulation via suppressing PI3K/Akt/NF-κB Signaling Processes.

Oncostatin M (OSM) plays a crucial role in diverse inflammatory reactions. Although the food bioactive compound naringenin (NAR) exerts various useful effects, including antitussive, anti-inflammatory, hepatoprotective, renoprotective, antiarthritic, antitumor, antioxidant, neuroprotective, antidepressant, antinociceptive, antiatherosclerotic, and antidiabetic effects, the modulatory mechanism of NAR on OSM expression in neutrophils has not been specifically reported. In the current work, we studied whether NAR modulates OSM release in neutrophil-like differentiated (d)HL-60 cells. To assess the modulatory effect of NAR, enzyme-linked immunosorbent assay (ELISA), quantitative real-time polymerase chain reaction (qRT-PCR), Western blotting, and immunofluorescence assay were employed. While exposure to granulocyte-macrophage colony-stimulating factor (GM-CSF) induced elevated OSM release and mRNA expression, the elevated OSM release and mRNA expression were diminished by the addition of NAR in dHL-60 cells. While the phosphorylation of phosphatidylinositol 3-kinase, protein kinase B (Akt), and nuclear factor (NF)-κB was upregulated by exposure to GM-CSF, the upregulated phosphorylation was inhibited by the addition of NAR in dHL-60 cells. Consequently, the results indicate that the food bioactive compound NAR may have a positive effect on health (in health promotion and improvement) or may play a role in the prevention of inflammatory diseases.

Background: Oncostatin M (OSM) is involved in several inflammatory responses. Tryptanthrin (TRYP), as a natural alkaloid, is a bioactive compound derived from indigo plants. Objectives/ Methods: The purpose of this study is to investigate the potential inhibitory activity of TRYP on OSM release from neutrophils using neutrophils-like differentiated (d)HL-60 cells and neutrophils from mouse bone marrow. Results: The results showed that TRYP reduced the production and mRNA expression levels of OSM in the granulocyte–macrophage colony-stimulating factor (GM-CSF)-stimulated neutrophils-like dHL-60 cells. In addition, TRYP decreased the OSM production levels in the GM-CSF-stimulated neutrophils from mouse bone marrow. TRYP inhibited the phosphorylation of phosphatidylinositol 3-kinase (PI3K), AKT, and nuclear factor (NF)-κB in the GM-CSF-stimulated neutrophils-like dHL-60 cells. Conclusions: Therefore, these results reveal for the first time that TRYP inhibits OSM release via the down-regulation of PI3K-AKT-NF-κB axis from neutrophils, presenting its potential as a therapeutic agent for inflammatory responses.

Cancer immunotherapy as a promising anti-cancer strategy has been widely studied in recent years. Stigmasterol (STIG), a phytosterol, is known to have various pharmacological effects, including anti-inflammatory effects. However, the pharmacological role of STIG on melanoma immunotherapy has not been investigated. The present study demonstrates the anti-melanoma potency of STIG through the regulation of PD-L1 levels. The results reveal that STIG reduces reactive oxygen species (ROS) levels induced by hydrogen peroxide and increases glutathione levels decreased by α-MSH in B16F10 cells. Moreover, STIG significantly decreases melanin content and tyrosinase activities elevated by α-MSH. It also suppresses nitric oxide production induced by α-MSH. Additionally, STIG induces apoptosis with the up-regulation of PARP activation. STIG inhibits IFN-γ-induced PD-L1 expression and STAT1 phosphorylation levels. STIG also reverses the up-regulation of PD-L1 and phosphorylated STAT1 levels augmented by cisplatin, and STIG enhances CD8(+) T-cell-mediated cell death against B16F10 cells. These findings represent the first evidence of pro-apoptotic activity of STIG on melanoma cells through the down-regulation of ROS and PD-L1 pathways. Therefore, STIG may be an effective candidate for melanoma immunotherapy.

Introduction: Among skin cancers, melanoma has a high mortality rate. Recent advances in immunotherapy, particularly through immune checkpoint modulation, have improved the clinical treatment of melanoma. Maltol has various bioactivities, including anti-oxidant and anti-inflammatory properties, but the anti-melanoma property of maltol remains underexplored. The aim of this work is to explore the anti-melanoma potential of maltol through regulating immune checkpoints.Methods: The immune checkpoint PD-L1 was analyzed using qPCR, immunoblots, and immunofluorescence. Melanoma sensitivity towards T cells was investigated via cytotoxicity, cell viability, and IL-2 assays employing CTLL-2 cells.Results: Maltol was found to reduce melanin contents, tyrosinase activity, and expression levels of tyrosinase and tyrosinase-related protein 1. Additionally, maltol suppressed the proliferative capacity of B16F10 and induced cell cycle arrest. Maltol increased apoptotic rates by elevating cleaved caspase-3 and PARP. The co-treatment with maltol and cisplatin revealed a synergistic effect on inhibiting growth and promoting apoptosis. Maltol suppressed IFN-γ-induced PD-L1 and cisplatin-upregulated PD-L1 by attenuating STAT1 phosphorylation, thereby enhancing cisplatin’s cytotoxicity against B16F10. Maltol augmented sensitivity to CTLL-2 cell-regulated melanoma destruction, leading to an increase in IL-2 production.Discussion: These findings demonstrate that maltol restricts melanoma growth through the downregulation of PD-L1 and elicits T cell-mediated anti-cancer responses, overcoming PD-L1-mediated immunotherapy resistance of cisplatin. Therefore, maltol can be considered as an effective therapeutic agent against melanoma.

Melanoma is the most invasive and lethal skin cancer. Recently, PD-1/PD-L1 pathway modulation has been applied to cancer therapy due to its remarkable clinical efficacy. SH003, a mixture of natural products derived from Astragalus membranaceus, Angelica gigas, and Trichosanthes kirilowii, and formononetin (FMN), an active constituent of SH003, exhibit anti-cancer and anti-oxidant properties. However, few studies have reported on the anti-melanoma activities of SH003 and FMN. This work aimed to elucidate the anti-melanoma effects of SH003 and FMN through the PD-1/PD-L1 pathway, using B16F10 cells and CTLL-2 cells. Results showed that SH003 and FMN reduced melanin content and tyrosinase activity induced by α-MSH. Moreover, SH003 and FMN suppressed B16F10 growth and arrested cells at the G2/M phase. SH003 and FMN also led to cell apoptosis with increases in PARP and caspase-3 activation. The pro-apoptotic effects were further enhanced when combined with cisplatin. In addition, SH003 and FMN reversed the increased PD-L1 and STAT1 phosphorylation levels induced by cisplatin in the presence of IFN-γ. SH003 and FMN also enhanced the cytotoxicity of CTLL-2 cells against B16F10 cells. Therefore, the mixture of natural products SH003 demonstrates therapeutic potential in cancer treatment by exerting anti-melanoma effects through the PD-1/PD-L1 pathway.

The cytokine oncostatin M (OSM) is regarded as a critical mediator in various inflammatory responses. While the gaseous signaling molecule hydrogen sulfide (H₂S) plays a role in a variety of pathophysiological conditions, such as hypertension, inflammatory pain, osteoarthritis, ischemic stroke, oxidative stress, retinal degeneration, and inflammatory responses, the underlying mechanism of H₂S action on OSM expression in neutrophils needs to be clarified. In this work, we studied how H₂S reduces OSM expression in neutrophil-like differentiated (d)HL-60 cells. To evaluate the effects of H₂S, sodium hydrosulfide (NaHS, a donor that produces H₂S), ELISA, real-time PCR (qPCR), immunoblotting, and immunofluorescence staining were utilized. Although exposure to granulocyte–macrophage colony-stimulating factor (GM-CSF) resulted in upregulated levels of production and mRNA expression of OSM, these upregulated levels were reduced by pretreatment with NaHS in dHL-60 cells. Similarly, the same pretreatment lowered phosphorylated levels of phosphatidylinositol 3-kinase, Akt, and nuclear factor-kB that had been elevated by stimulation with GM-CSF. Overall, our results indicated that H₂S could be a therapeutic agent for inflammatory disorders via suppression of OSM.

An herbal mixture (SH003) of Astragalus membranaceus, Trichosanthes kirilowii, and Angelica gigas exhibits therapeutic effects on carcinomas and immunosuppression. However, the role of JRP-SNF102, which is an advanced mixture of SH003, in regulating inflammatory responses is unexplored. We aim to substantiate the therapeutic potential of JRP-SNF102 and its active component, formononetin (FMN), as a functional food that moderates inflammatory responses. The inhibitory effects of JRP-SNF102 or FMN on thymic stromal lymphopoietin (TSLP) levels were evaluated in phorbol 12-myristate 13-acetate (PMA) plus A23187-activated human mast cell line-1 (HMC-1) cells and a mouse model of PMA-induced ear edema. The JRP-SNF102 or FMN inhibited the secretion and mRNA expression of TSLP and vascular endothelial growth factor (VEGF) in the activated HMC-1 cells. The expression levels of murine double minute 2 (MDM2), hypoxia-inducible factor 1α (HIF1α), and NF-κB were also suppressed by JRP-SNF102 or FMN in the activated HMC-1 cells. The JRP-SNF102 or FMN inhibited TSLP and VEGF levels, attenuating redness and ear thickness in mice with acute ear edema; JRP-SNF102 or FMN reduced the expression levels of MDM2, HIF1α, and NF-κB in the ear tissues. These findings suggest the potential for JRP-SNF102 as a functional food in the treatment of inflammatory skin disorders through suppression of TSLP and VEGF.