Screening for Active Compounds Targeting Human Natural Killer Cell Activation Identifying Daphnetin as an Enhancer for IFN-γ Production and Direct Cytotoxicity

Unravelling the role of Interleukin-12 in Neuroinflammatory mechanisms: Pathogenic pathways linking Neuroinflammation to neuropsychiatric disorders

Neuropsychiatric disorders are clinically characterized conditions involving both neurology and psychiatry, arising from dysfunctioning of cerebral function, or indirect effects of extra cerebral disease. Neuropsychiatric disorders tend to influence emotions, mood, and brain functioning. Growing evidence indicates that the etiology of these disorders is not confined to neuronal abnormalities but extends to include inflammation. While the underlying mechanism of these disorders is still in its infancy, recent data highlights the significant role of neuroinflammation in their pathophysiology. Neuroinflammation concerns the inflammation within the neural tissue characterized by alteration in astrocytes, cytokines, microglia, and chemokines within the central nervous system. The cytokines include IFN-γ, IL-1β, IL-2, IL4, IL-6, IL-8, IL-10, and IL-12. This review focuses on interleukin-12 (IL-12), a key mediator of neuroinflammation, and its potential involvement in neuropsychiatric disorders. IL-12 promotes neuroinflammation and influences neurotransmitter systems. Additionally, it also affects the HPA axis, impairs neuroplasticity, and activates microglia by interacting with TLR, JAK-STAT, PI3K/Akt, GSK-3, NMDA, MAPK, PKC, VEGFR, ROCK, and Wnt signaling pathways and elicit its role in ND. In this review, we dwell on the current evidence supporting IL-12's pathogenic role and explore the possible mechanisms by which it contributes to the development and progression of these conditions. This review aims to provide insights that may aid in future therapeutic strategies by illuminating the interplay between neuroinflammation and neuropsychiatric disorders.

MicroRNA-767-5p promotes metastasis but improves chemotherapeutic and radiotherapeutic sensitivity of osteosarcoma

The aim of this study was to explore the role of microRNA-767-5p (miR-767-5p) in regulating the osteosarcoma (OS) prognosis, metastasis and sensitivity to chemotherapeutic and radiotherapeutic sensitivity. We observed that miR-767-5p expression in the specimens of patients with metastatic OS was higher than in healthy individuals and was also negatively correlated with the overall survival of patients with OS. Functional assays (CCK-8, transwell, colony formation) and a tumor xenograft model demonstrated that miR-767-5p over-expression in both U2OS and 143B OS cell lines promoted cell invasion and migration without affecting proliferation, whereas its knockdown had opposite effects. Notably, miR-767-5p over-expression enhanced the sensitivity of both U2OS and 143B cells to chemotherapy or radiotherapy. Combing target gene prediction, RNA-sequencing and overall survival analysis, we identified aryl hydrocarbon receptor (AHR) as the potential target gene of miR-767-5p. Luciferase assay confirmed that miR-767-5p promoted the 3'-UTR activity of AHR through direct binding. Strikingly, AHR over-expression in both U2OS and 143B cells suppressed invasion, migration while reduced therapeutic sensitivity to chemotherapy and radiotherapy-thereby reversing miR-767-5p's phenotypic impact. Therefore, this study suggested that miR-767-5p promotes OS metastasis but improves its sensitivity to radiotherapy and chemotherapy.

Identification of Molecular Subtypes and Prognostic Features of Breast Cancer Based on TGF-β Signaling-related Genes

Objectives

The TGF-β signaling pathway is widely acknowledged for its role in various aspects of cancer progression, including cellular invasion, epithelial-mesenchymal transition, and immunosuppression. Immune checkpoint inhibitors (ICIs) and pharmacological agents that target TGF-β offer significant potential as therapeutic options for cancer. However, the specific role of TGF-β in prognostic assessment and treatment strategies for breast cancer (BC) remains unclear.

Methods

The Cancer Genome Atlas (TCGA) database was utilized to develop a predictive model incorporating five TGF-β signaling-related genes (TSRGs). The GSE161529 dataset from the Gene Expression Omnibus was employed to conduct single-cell analyses aimed at further elucidating the characteristics of these TSRGs. Additionally, an unsupervised clustering algorithm was applied to categorize BC patients into two distinct groups based on the five TSRGs, with a focus on immune response and overall survival (OS). Further investigations were conducted to explore variations in pharmacotherapy and the tumor microenvironment across different patient cohorts and clusters.

Results

The predictive model for BC identified five TSRGs: FUT8, IFNG, ID3, KLF10, and PARD6A. Single-cell analysis revealed that IFNG is predominantly expressed in CD8+ T cells. Consensus clustering effectively categorized BC patients into two distinct clusters, with cluster B demonstrating a longer OS and a more favorable prognosis. Immunological assessments indicated a higher presence of immune checkpoints and immune cells in cluster B, suggesting a greater likelihood of responsiveness to ICIs.

Conclusion

The findings of this study highlight the potential of the TGF-β signaling pathway for prognostic classification and the development of personalized treatment strategies for BC patients, thereby enhancing our understanding of its significance in BC prognosis.

mTOR Signaling Promotes Rapid m6A mRNA Methylation to Regulate NK-Cell Activation and Effector Functions

NK cells can be rapidly activated in response to cytokines during host defense against malignant cells or viral infection. However, it remains unclear what mechanisms precisely and rapidly regulate the expression of a large number of genes involved in activating NK cells. In this study, we discovered that NK-cell N6-methyladenosine (m6A) methylation levels were rapidly upregulated upon short-term NK-cell activation and were repressed in the tumor microenvironment (TME). Deficiency of methyltransferase-like 3 (METTL3) or METTL14 moderately influenced NK-cell homeostasis, while double-knockout of METTL3/14 more significantly impacted NK-cell homeostasis, maturation, and antitumor immunity. This suggests a cooperative role of METTL3 and METTL14 in regulating NK-cell development and effector functions. Using methylated RNA immunoprecipitation sequencing, we demonstrated that genes involved in NK-cell effector functions, such as Prf1 and Gzmb, were directly modified by m6A methylation. Furthermore, inhibiting mTOR complex 1 activation prevented m6A methylation levels from increasing when NK cells were activated, and this could be restored by S-adenosylmethionine supplementation. Collectively, we have unraveled crucial roles for rapid m6A mRNA methylation downstream of the mTOR complex 1-S-adenosylmethionine signal axis in regulating NK-cell activation and effector functions.

The molecular effects underlying the pharmacological activities of daphnetin

As an increasingly well-known derivative of coumarin, daphnetin (7,8-dithydroxycoumarin) has demonstrated various pharmacological activities, including anti-inflammation, anti-cancer, anti-autoimmune diseases, antibacterial, organ protection, and neuroprotection properties. Various studies have been conducted to explore the action mechanisms and synthetic methods of daphnetin, given its therapeutic potential in clinical. Despite these initial insights, the precise mechanisms underlying the pharmacological activities of daphnetin remain largely unknown. In order to address this knowledge gap, we explore the molecular effects from the perspectives of signaling pathways, NOD-like receptor protein 3 (NLRP3) inflammasome and inflammatory factors; and try to find out how these mechanisms can be utilized to inform new combined therapeutic strategies.

Daphnetin alleviates silica-induced pulmonary inflammation and fibrosis by regulating the PI3K/AKT1 signaling pathway in mice

Silicosis is a hazardous occupational disease caused by inhalation of silica, characterized by persistent lung inflammation that leads to fibrosis and subsequent lung dysfunction. Moreover, the complex pathophysiology of silicosis, the challenges associated with early detection, and the unfavorable prognosis contribute to the limited availability of treatment options. Daphnetin (DAP), a natural lactone, has demonstrated various pharmacological properties, including anti-inflammatory, anti-fibrotic, and pulmonary protective effects. However, the effects of DAP on silicosis and its molecular mechanisms remain uncover. This study aimed to evaluate the therapeutic effects of DAP against pulmonary inflammation and fibrosis using a silica-induced silicosis mouse model, and investigate the potential mechanisms and targets through network pharmacology, proteomics, molecular docking, and cellular thermal shift assay (CETSA). Here, we found that DAP significantly alleviated silica-induced lung injury in mice with silicosis. The results of H&E staining, Masson staining, and Sirius red staining indicated that DAP effectively reduced the inflammatory response and collagen deposition over a 28-day period following lung exposure to silica. Furthermore, DAP reduced the number of TUNEL-positive cells, increased the expression levels of Bcl-2, and decreased the expression of Bax and cleaved caspase-3 in the mice with silicosis. More importantly, DAP suppressed the expression levels of NLRP3 signaling pathway-related proteins, including NLRP3, ASC, and cleaved caspase-1, thereby inhibiting silica-induced lung inflammation. Further studies demonstrated that DAP possesses the ability to inhibit the epithelial mesenchymal transition (EMT) induced by silica through the inhibition of the TGF-β1/Smad2/3 signaling pathway. The experimental results of proteomic analysis found that the PI3K/AKT1 signaling pathway was the key targets of DAP to alleviate lung injury induced by silica. DAP significantly inhibited the activation of the PI3K/AKT1 signaling pathway induced by silica in lung tissues. The conclusion was also verified by the results of molecular and CETSA. To further verify this conclusion, the activity of PI3K/AKT1 signaling pathway was inhibited in A549 cells using LY294002. When the A549 cells were pretreated with LY294002, the protective effect of DAP on silica-induced injury was lost. In conclusion, the results of this study suggest that DAP alleviates pulmonary inflammation and fibrosis induced by silica by modulating the PI3K/AKT1 signaling pathway, and holds promise as a potentially effective treatment for silicosis.

mTORC2 acts as a gatekeeper for mTORC1 deficiency-mediated impairments in ILC3 development

Group 3 innate lymphoid cells (ILC3s) are mediators of intestinal immunity and barrier function. Recent studies have investigated the role of the mammalian target of rapamycin complex (mTOR) in ILC3s, whereas the mTORC1-related mechanisms and crosstalk between mTORC1 and mTORC2 involved in regulating ILC3 homeostasis remain unknown. In this study, we found that mTORC1 but not mTORC2 was critical in ILC3 development, IL-22 production, and ILC3-mediated intestinal homeostasis. Single-cell RNA sequencing revealed that mTORC1 deficiency led to disruption of ILC3 heterogeneity, showing an increase in differentiation into ILC1-like phenotypes. Mechanistically, mTORC1 deficiency decreased the expression of NFIL3, which is a critical transcription factor responsible for ILC3 development. The activities of both mTORC1 and mTORC2 were increased in wild-type ILC3s after activation by IL-23, whereas inhibition of mTORC1 by Raptor deletion or rapamycin treatment resulted in increased mTORC2 activity. Previous studies have demonstrated that S6K, the main downstream target of mTORC1, can directly phosphorylate Rictor to dampen mTORC2 activity. Our data found that inhibition of mTORC1 activity by rapamycin reduced Rictor phosphorylation in ILC3s. Reversing the increased mTORC2 activity via heterozygous or homozygous knockout of Rictor in Raptor-deleted ILC3s resulted in severe ILC3 loss and complete susceptibility to intestinal infection in mice with mTORC1 deficiency (100% mortality). Thus, mTORC1 acts as a rheostat of ILC3 heterogeneity, and mTORC2 protects ILC3s from severe loss of cells and immune activity against intestinal infection when mTORC1 activity is diminished.

Recombinant oncolytic adenovirus armed with CCL5, IL-12, and IFN-γ promotes CAR-T infiltration and proliferation in vivo to eradicate local and distal tumors

The efficacy of chimeric antigen receptor T (CAR-T) cells for solid tumors remains unsatisfactory due to the limited tumor infiltration and immunosuppressive microenvironment. To overcome these limitations, the genetically engineered recombinant oncolytic adenoviruses (OAVs) that conditionally replicate in tumor cells were developed to modify the tumor microenvironment (TME) to facilitate CAR-T-mediated tumor eradication. Here in the present study, a novel recombinant OAV carrying CCL5, IL12, and IFN-γ controlled by Ki67 promoter was constructed (named AdKi67-C3). The antitumor activity of AdKi67-C3 was tested in vitro and in vivo by using mono administration or combing with CAR-T cells targeting B7H3. It proved that CCL5 expressed by AdKi67-C3 indeed induced more CAR-T migration in vitro and CAR-T infiltration in tumor mass in vivo. Meanwhile, cytokines of IFN-γ and IL12 secreted by AdKi67-C3-infected tumor cells significantly promoted proliferation and persistence of CAR-T cells in vitro and in vivo. In tumor-bearing xenograft mouse models of kidney, prostate or pancreatic cancer, local pretreatment with AdKi67-C3 dramatically enhanced CAR-T cell efficacy and eliminated local and distant tumors. More importantly, mice achieving complete tumor regression resisted to re-challenge with the same tumor cells, suggesting establishment of long-term antitumor immune response. Therefore, OAVs armored with cytokines could be developed as a bioenhancer to defeat the immunosuppressive microenvironment and improve therapeutic efficacy of CAR-T in solid tumors.

Daphnetin, a Coumarin with Anticancer Potential against Human Melanoma: In Vitro Study of Its Effective Combination with Selected Cytostatic Drugs

(1) The treatment of metastatic or drug-resistant melanoma is still a significant therapeutic problem. The aim of this study was to evaluate the anticancer potential of daphnetin (7,8-dihydroxycoumarin) and its combinations with five different cytostatic drugs (mitoxantrone, docetaxel, vemurafenib, epirubicin and cisplatin). (2) The viability, proliferation and cytotoxicity of daphnetin against four human malignant melanoma cell lines were evaluated. The interactions were assessed using isobolographic analysis for the combinations of daphnetin with each of the five cytostatic drugs. (3) Daphnetin showed anticancer activity against malignant melanoma, with IC₅₀ values ranging from 40.48 ± 10.90 µM to 183.97 ± 18.82 µM, depending on the cell line. The combination of daphnetin with either vemurafenib or epirubicin showed an antagonistic interaction. Moreover, additive interactions were observed for the combinations of daphnetin with cisplatin and docetaxel. The most desirable synergistic interactions for human melanoma metastatic cell lines were observed for the combination of daphnetin with mitoxantrone. (4) The obtained results suggest that daphnetin should not be combined with vemurafenib or epirubicin in the treatment of malignant melanoma due to the abolition of their anticancer effects. The combination of daphnetin with mitoxantrone is beneficial in the treatment of metastatic melanoma due to their synergistic interaction.

Effects of Leea indica leaf extracts and its phytoconstituents on natural killer cell-mediated cytotoxicity in human ovarian cancer

BACKGROUND

The rich biodiversity of medicinal plants and their importance as sources of novel therapeutics and lead compounds warrant further research. Despite advances in debulking surgery and chemotherapy, the risks of recurrence of ovarian cancer and resistance to therapy are significant and the clinical outcomes of ovarian cancer remain poor or even incurable.

OBJECTIVE

This study aims to investigate the effects of leaf extracts from a medicinal plant Leea indica and its selected phytoconstituents on human ovarian cancer cells and in combination with oxaliplatin and natural killer (NK) cells.

METHODS

Fresh, healthy leaves of L. indica were harvested and extracted in 70% methanol by maceration. The crude extract was partitioned with n-hexane, dichloromethane and ethyl acetate. Selected extracts and compounds were analyzed for their effects on cell viability of human ovarian cancer cells, NK cell cytotoxicity, and stress ligands expression for NK cell receptors. They were also evaluated for their effects on TNF-α and IL-1β production by enzyme-linked immunosorbent assay in lipopolysaccharide-stimulated human U937 macrophages.

RESULTS

Leaf extracts of L. indica increased the susceptibility of human ovarian tumor cells to NK cell-mediated cytotoxicity. Treatment of cancer cells with methyl gallate but not gallic acid upregulated the expression of stress ligands. Tumor cells pretreated with combination of methyl gallate and low concentration of oxaliplatin displayed increased levels of stress ligands expression and concomitantly enhanced susceptibility to NK cell-mediated cytolysis. Further, NK cells completely abrogated the growth of methyl gallate-pretreated ovarian cancer cells. The leaf extracts suppressed TNF-α and IL-1β production in human U937 macrophages. Methyl gallate was more potent than gallic acid in down-regulating these cytokine levels.

CONCLUSIONS

We demonstrated for the first time that leaf extracts of L. indica and its phytoconstituent methyl gallate enhanced the susceptibility of ovarian tumor cells to NK cell cytolysis. These results suggest that the combined effect of methyl gallate, oxaliplatin and NK cells in ovarian cancer cells warrants further investigation, for example for refractory ovarian cancer. Our work is a step towards better scientific understanding of the traditional anticancer use of L. indica.

Epigenetic drug screen identified IOX1 as an inhibitor of Th17-mediated inflammation through targeting TET2

BACKGROUND

Targeting helper T cells, especially Th17 cells, has become a plausible therapy for many autoimmune diseases.

METHODS

Using an in vitro culture system, we screened an epigenetics compound library for inhibitors of IFN-γ and IL-17 expression in murine Th1 and Th17 cultures.

FINDINGS

This identified IOX1 as an effective suppressor of IL-17 expression in both murine and human CD4⁺ T cells. Furthermore, we found that IOX1 suppresses Il17a expression directly by targeting TET2 activity on its promoter in Th17 cells. Using established pre-clinical models of intraocular inflammation, treatment with IOX1 in vivo reduced the migration/infiltration of Th17 cells into the site of inflammation and tissue damage.

INTERPRETATION

These results provide evidence of the strong potential for IOX1 as a viable therapy for inflammatory diseases, in particular of the eye.

FUNDING

This study was supported by the National Key Research and Development Program of China 2021YFA1101200 (2021YFA1101204) to LW and XW; the National Natural Science Foundation of China 81900844 to XH and 82171041 to LW; the China Postdoctoral Science Foundation 2021M700776 and the Scientific Research Project of Guangdong Provincial Bureau of Traditional Chinese Medicine 20221373 to YZ; and the National Institute for Health Research (NIHR) Biomedical Research Centre at Moorfields Eye Hospital NHS (National Health Service) Foundation Trust and University College London Institute of Ophthalmology, UK (DAC, LPS, PJPL, MS, ADD and RWJL). The views expressed are those of the authors and not necessarily those of the NIHR or the UK's Department of Health and Social Care.

Recent Advances with KDM4 Inhibitors and Potential Applications

The histone lysine demethylase 4 (KDM4) family plays an important role in regulating gene transcription, DNA repair, and metabolism. The dysregulation of KDM4 functions is associated with many human disorders, including cancer, obesity, and cardiovascular diseases. Selective and potent KDM4 inhibitors may help not only to understand the role of KDM4 in these disorders but also to provide potential therapeutic opportunities. Here, we provide an overview of the field and discuss current status, challenges, and opportunities lying ahead in the development of KDM4-based anticancer therapeutics.

Docosahexaenoic acid supplementation represses the early immune response against murine cytomegalovirus but enhances NK cell effector function

BACKGROUND

Docosahexaenoic acid (DHA) supplementation is beneficial for several chronic diseases; however, its effect on immune regulation is still debated. Given the prevalence of cytomegalovirus (CMV) infection and because natural killer (NK) cells are a component of innate immunity critical for controlling CMV infection, the current study explored the effect of a DHA-enriched diet on susceptibility to murine (M) CMV infection and the NK cell effector response to MCMV infection.

RESULTS

Male C57BL/6 mice fed a control or DHA-enriched diet for 3 weeks were infected with MCMV and sacrificed at the indicated time points postinfection. Compared with control mice, DHA-fed mice had higher liver and spleen viral loads at day 7 postinfection, but final MCMV clearance was not affected. The total numbers of NK cells and their terminal mature cell subset (KLRG1+ and Ly49H+ NK cells) were reduced compared with those in control mice at day 7 postinfection but not day 21. DHA feeding resulted in higher IFN-γ and granzyme B expression in splenic NK cells at day 7 postinfection. A mechanistic analysis showed that the splenic NK cells of DHA-fed mice had enhanced glucose uptake, increased CD71 and CD98 expression, and higher mitochondrial mass than control mice. In addition, DHA-fed mice showed reductions in the total numbers and activation levels of CD4+ and CD8+ T cells.

CONCLUSIONS

These results suggest that DHA supplementation represses the early response to CMV infection but preserves NK cell effector functions by improving mitochondrial activity, which may play critical roles in subsequent MCMV clearance.

Identification of nafamostat mesylate as a selective stimulator of NK cell IFN-γ production via metabolism-related compound library screening

Natural killer (NK) cells play important roles in controlling virus-infected and malignant cells. The identification of new molecules that can activate NK cells may effectively improve the antiviral and antitumour activities of these cells. In this study, by using a commercially available metabolism-related compound library, we initially screened the capacity of compounds to activate NK cells by determining the ratio of interferon-gamma (IFN-γ)⁺ NK cells by flow cytometry after the incubation of peripheral blood mononuclear cells (PBMCs) with IL-12 or IL-15 for 18 h. Our data showed that eight compounds (nafamostat mesylate (NM), loganin, fluvastatin sodium, atorvastatin calcium, lovastatin, simvastatin, rosuvastatin calcium, and pitavastatin calcium) and three compounds (NM, elesclomol, and simvastatin) increased the proportions of NK cells and CD3⁺ T cells that expressed IFN-γ among PBMCs cultured with IL-12 and IL-15, respectively. When incubated with enriched NK cells (purity ≥ 80.0%), only NM enhanced NK cell IFN-γ production in the presence of IL-12 or IL-15. When incubated with purified NK cells (purity ≥ 99.0%), NM promoted NK cell IFN-γ secretion in the presence or absence of IL-18. However, NM showed no effect on NK cell cytotoxicity. Collectively, our study identifies NM as a selective stimulator of IFN-γ production by NK cells, providing a new strategy for the prevention and treatment of infection or cancer in select populations.