The kinase AKT1 potentiates the suppressive functions of myeloid-derived suppressor cells in inflammation and cancer

Siglec-E augments adipose tissue inflammation by modulating TRAF3 signaling and monocytic myeloid-derived suppressor cells during obesity

Background

Obesity is associated with dysregulated metabolism and low-grade chronic inflammation in adipose tissue (AT). Immune cells, including macrophages, T cells, and neutrophils, infiltrate the AT and secrete proinflammatory cytokines to exacerbate the AT inflammation. RNA-Seq analysis of AT immune cells isolated from mice fed a high-fat diet (HFD) versus normal fat diet (ND) identified a panel of genes that were markedly downregulated, including sialic acid-binding Ig-like lectin E (siglec-E), in HFD compared to ND mice.

Methods

A series of experiments in wild-type (WT) and siglec-E knockout (siglec-E KO) mice was designed to investigate the effect of HFD on the functional role of siglec-E in the regulation of AT inflammation and adipogenesis. We analyzed the changes in immune phenotypes, inflammatory response, adipogenesis, and levels of cytokines and chemokines after HFD and ND feeding.

Results

HFD consumption significantly increased the body weight and blood glucose levels in siglec-E KO mice relative to those of WT mice. This was associated with an increased infiltration of macrophages, CXCR3 expressing CD8 T cells, and monocytic myeloid-derived suppressor cells (M-MDSCs) with a concomitant decrease in numbers of dendritic cells (DCs), in the AT of siglec-E KO fed HFD versus the WT HFD counterparts. The HFD-fed siglec-E KO mice also exhibited elevated expression of intracellular Akt and TNF receptor-associated factor 3 (TRAF3) signaling, inducing C/EBPα, FASN, PPARγ, and resistin in suprascapular AT compared to WT HFD-fed mice. Taken together, these results suggest that a genetic deficiency of siglec-E plays a key role in inducing AT inflammation by differentially altering M-MDSCs and CD8+CXCR3+ T cell function and adipogenesis by TRAF3 and Akt signaling in AT.

Conclusion

Our findings strongly suggest that modulation of siglec-E pathways might have a protective effect at least in part against AT inflammation and metabolic disorders.

Network pharmacology in combination with bibliometrics analysis on the mechanism of compound Kushen injection in the treatment of radiation pneumonia and lung cancer

Radiation pneumonia is a common adverse reaction during radiotherapy in lung cancer patients, which negatively impacts the quality of life and survival of patients. Recent studies have shown that compound Kushen injection (CKI), a traditional Chinese medicine (TCM), has great anti-inflammatory and anticancer potential, but the mechanism is still unclear. We used CiteSpace, the R package "bibliometrix," and VOSviewers to perform a bibliometrics analysis of 162 articles included from the Web of Science core collection. A network pharmacology-based approach was used to screen effective compounds, screen and predict target genes, analyze biological functions and pathways, and construct regulatory networks and protein interaction networks. Molecular docking experiments were used to identify the affinity of key compounds and core target. The literature metrology analysis revealed that over 90% of the CKI-related studies were conducted by Chinese scholars and institutions, with a predominant focus on tumors, while research on radiation pneumonia remained limited. Our investigation identified 60 active ingredients of CKI, 292 genes associated with radiation pneumonia, 533 genes linked to lung cancer, and 37 common targets of CKI in the treatment of both radiation pneumonia and lung cancer. These core potential targets were found to be significantly associated with the OS of lung cancer patients, and the key compounds exhibited a good docking affinity with these targets. Additionally, GO and KEGG enrichment analysis highlighted that the bioinformatics annotation of these common genes mainly involved ubiquitin protein ligase binding, cytokine receptor binding, and the PI3K/Akt signaling pathway. Our study revealed that the main active components of CKI, primarily quercetin, luteolin, and naringin, might act on major core targets, including AKT1, PTGS2, and PPARG, and further regulated key signaling pathways such as the PI3K/Akt pathway, thereby playing a crucial role in the treatment of radiation pneumonia and lung cancer. Moreover, this study had a certain promotional effect on further clinical application and provided a theoretical basis for subsequent experimental research.

IRF4 regulates myeloid-derived suppressor cells expansion and function in Schistosoma japonicum-infected mice

BACKGROUND

Interferon regulatory factor 4 (IRF4) is a crucial member of the IRF family of transcription factors and is pivotal in orchestrating the body's defense against tumors and infections by modulating the differentiation and functionality of immune cells. The role of IRF4 in mice during Schistosoma japonicum infection, as well as the effects of IRF4 deficiency on myeloid-derived suppressor cells (MDSCs), remains inadequately understood.

METHODS

Hematoxylin and eosin staining was used to evaluate the pathological damage in different organs of mice following infection with S. japonicum. Flow cytometry was employed to study the effect of IRF4 on the proliferation and function of myeloid-derived suppressor cells (MDSCs) in S. japonicum-infected mice.

RESULTS

Knockout of IRF4 in myeloid cells significantly mitigated pathological damage to the liver and lungs in mice infected with S. japonicum. Knockout of IRF4 in myeloid cells also inhibited the expansion and functionality of MDSCs by downregulating programmed death ligand 2 (PD-L2) expression and interleukin-1 alpha (IL-1α) secretion in mice infected with S. japonicum. Mechanistic studies revealed that IRF4 deficiency inhibited the expansion and function of MDSCs and that this inhibition was mediated by the STAT3 and AKT signaling pathways. Also, IRF4 myeloid knockout promoted the expansion of T cells in S. japonicum-infected mice, but had no significant effect on B cell aggregation.

CONCLUSIONS

Overall, these findings highlight the importance of IRF4 in regulating MDSCs and their impact on tissue damage during S. japonicum infection, providing valuable insights into potential therapeutic targets for managing the pathological consequences of this parasitic infection.

Exploring the Potential of Glycolytic Modulation in Myeloid-Derived Suppressor Cells for Immunotherapy and Disease Management

Recent advancements in various technologies have shed light on the critical role of metabolism in immune cells, paving the way for innovative disease treatment strategies through immunometabolism modulation. This review emphasizes the glucose metabolism of myeloid-derived suppressor cells (MDSCs), an emerging pivotal immunosuppressive factor especially within the tumor microenvironment. MDSCs, an immature and heterogeneous myeloid cell population, act as a double-edged sword by exacerbating tumors or mitigating inflammatory diseases through their immune-suppressive functions. Numerous recent studies have centered on glycolysis of MDSC, investigating the regulation of altered glycolytic pathways to manage diseases. However, the specific changes in MDSC glycolysis and their exact functions continue to be areas of ongoing discussion yet. In this paper, we review a range of current findings, including the latest research on the alteration of glycolysis in MDSCs, the consequential functional alterations in these cells, and the outcomes of attempts to modulate MDSC functions by regulating glycolysis. Ultimately, we will provide insights into whether these research efforts could be translated into clinical applications.

The effect of adoptive transferring myeloid-derived suppressor cells in ventilator-induced lung injury mice

The effects of adoptive transferring myeloid-derived suppressor cells (MDSCs) to mice with ventilator-induced lung injury (VILI) are unclear. Our objective was to investigate the effects of adoptively transferring MDSCs in VILI. The mouse model was created by introducing mechanical ventilation through a high tidal volume of 20 ml/kg for 4 h. Inflammation-induced MDSCs (iMDSCs) were collected from the bone marrow of mice with cecal ligation and puncture. iMDSCs were administrated through retrobulbar angular vein 1 h before the mechanical ventilation. The control group was anesthetized and maintained spontaneous respiration. After the termination of mechanical ventilation, bronchoalveolar lavage fluid (BALF) and lung samples 6 h were collected. The concentrations of BALF protein, levels of inflammatory mediators, and white blood cells were all significantly decreased in mice treated with iMDSCs. Histological examinations indicated reduced lung damage after iMDSCs treatment. Moreover, adoptive transfer of iMDSCs could reduce CD4+ T-cell counts and inhibit its inflammatory cytokine secretion. iMDSCs treatment was found to had no immunostimulatory effects or cause secondary infections in mice. In conclusion, MDSCs might be a potential targeted therapy for alleviating the inflammatory response of VILI mice in a T-cell dependent manner.

Mechanism exploration of Osteoking in the treatment of lumbar disc herniation based on network pharmacology and molecular docking

OBJECTIVE

Lumbar disc herniation (LDH) is a common spinal surgical disease. Low back and leg pain caused by LDH is the main factor leading to functional disability, which has caused a serious burden to patients and society. Osteoking can delay the progression of osteoporosis and osteoarthritis, and even has a significant effect on the prevention of deep vein thrombosis after fracture surgery. In recent years, it has been gradually used in the treatment of LDH and has received significant results. However, the underlying mechanism remains unclear. The aim of this study was to predict the mechanism of Osteoking in the treatment of LDH through network pharmacology and verify it by molecular docking method.

METHODS

The TCMSP database was used to collect the relevant active components and targets of Osteoking, while the GeneCards, OMIM and DisGeNET databases were utilized to collect the relevant disease targets of LDH. The Venny 2.1.0 software was employed to obtain the intersecting gene targets of Osteoking and LDH. PPI network construction and core target selection were performed using Cytoscape 3.9.0 software. The Metascape database was used for GO and KEGG enrichment analysis of the relevant targets. Finally, molecular docking was conducted using AutoDock software.

RESULTS

The study identified 116 potential targets and 26 core targets for the treatment of LDH with Osteoking. Pathways in cancer, Alzheimer's disease, microRNAs in cancer and the IL-17 signalling pathway were among the main involved signalling pathways. Molecular docking results demonstrated that the key targets AKT1, IL-6, ALB, TNF and IL-1β exhibited relatively stable binding activities with the main active components of Osteoking.

CONCLUSIONS

Osteoking can alleviate the symptoms of lumbar disc herniation through the modulation of multiple targets and signalling pathways.

To study the protective effect of Huangqi Baihe Granules on Radiation brain injury based on network pharmacology and experiment

ETHNOPHARMACOLOGICAL RELEVANCE

Huangqi baihe Granules (HQBHG), which is a key Chinese medical prescription, has a remarkable efficacy in oxidative stress and inflammation. Nevertheless, the therapeutic effect on Radiation brain injury (RBI) has rarely been studied.

AIM OF THE STUDY

The study aimed to verify the effect of HQBHG against RBI and explore its potential mechanism.

METHODS

The potential targets and mechanisms of HQBHG against RBI were predicted by network pharmacology and verified by established rat model of RBI Firstly, the therapeutic effect of HQBHG in RBI was confirmed by water maze test, HE staining and Enzyme-linked immunosorbent assay (ELISA). Secondly, the potential critical anti-RBI pathway of HQBHG was further explored by water maze, HE staining, immunofluorescence assays, ELISA and western blot.

RESULTS

A total of 43 HQBHG anti-RBI targets were obtained. Gene Ontology (Go) and Kyoto Encyclopedia of Genes and Genomes (KEGG) functional annotations showed that the treatment of HQBHG in RBI might be mainly related to oxidative stress, inflammation and PI3K/AKT pathway. Experimental studies have indicated that HQBHG can improve spatial learning and memory ability, alleviate pathological damage of brain tissue in RBI of rats. HQBHG also can down-regulate the levels of IL-1β, TNF-α, ROS and MDA, meanwhile, GSH was significantly up-regulated. In addition, the HQBHG can increase the protein expression phosphorylations PI3K (p-PI3K), phosphorylations AKT(p-AKT) and Nrf2 in the brain tissue of RBI.

CONCLUSION

HQBHG may alleviated RBI by regulated oxidative stress and inflammatory response through PI3K/AKT/Nrf2 pathway.

Cortex Mori extracts induce apoptosis and inhibit tumor invasion via blockage of the PI3K/AKT signaling in melanoma cells

Melanoma, the most aggressive and deadliest form of skin cancer, has attracted increased attention due to its increasing incidence worldwide. The Cortex Mori (CM) has long been used as a classical traditional Chinese medicine (TCM) to treat various diseases, including cancer. The bioactive components and underlying mechanisms, however, remain largely unknown. The current study aims to investigate the anti-melanoma effects of CM and potential mechanisms through combined network pharmacology and bioinformatic analyses, and validated by in vitro and in vivo experiments. We report here that CM has anti-melanoma activity both in vitro and in vivo. Furthermore, 25 bioactive compounds in CM were found to share 142 melanoma targets, and network pharmacology and enrichment analyses suggested that CM inhibits melanoma through multiple biological processes and signaling pathways, particularly the PI3K-AKT signaling inhibition and activation of apoptotic pathways, which were further confirmed by biochemical and histological examinations. Finally, partial CM-derived bioactive compounds were found to show anti-melanoma effects, validating the anti-melanoma potential of bioactive ingredients of CM. Taken together, these results reveal bioactive components and mechanisms of CM in inhibiting melanoma, providing them as potential anti-cancer natural products for the treatment of melanoma.

ISOC1 Modulates Inflammatory Responses in Macrophages through the AKT1/PEX11B/Peroxisome Pathway

Inflammation underlies a variety of physiological and pathological processes and plays an essential role in shaping the ensuing adaptive immune responses and in the control of pathogens. However, its physiological functions are not completely clear. Using a LPS-treated RAW264.7 macrophage inflammation model, we found that the production of inflammatory cytokines in ISOC1-deficient cells was significantly higher than that in the control group. It was further proved that ISOC1 deficiency could activate AKT1, and the overactivation of AKT1 could reduce the stability of PEX11B through protein modification, thereby reducing the peroxisome biogenesis and thus affecting inflammation. In this study, we reported for the first time the role of ISOC1 in innate immunity and elucidated the mechanism by which ISOC1 regulates inflammation through AKT1/PEX11B/peroxisome. Our results defined a new role of ISOC1 in the regulatory mechanism underlying the LPS-induced inflammatory response.

Pharmacological modulation of myeloid-derived suppressor cells to dampen inflammation

Myeloid-derived suppressor cells (MDSCs) are a heterogeneous cell population with potent suppressive and regulative properties. MDSCs’ strong immunosuppressive potential creates new possibilities to treat chronic inflammation and autoimmune diseases or induce tolerance towards transplantation. Here, we summarize and critically discuss different pharmacological approaches which modulate the generation, activation, and recruitment of MDSCs in vitro and in vivo, and their potential role in future immunosuppressive therapy.

Circulating Tumor Cell Transcriptomics as Biopsy Surrogates in Metastatic Breast Cancer

BACKGROUND

Metastatic breast cancer (MBC) and the circulating tumor cells (CTCs) leading to macrometastases are inherently different than primary breast cancer. We evaluated whether whole transcriptome RNA-Seq of CTCs isolated via an epitope-independent approach may serve as a surrogate for biopsies of macrometastases.

METHODS

We performed RNA-Seq on fresh metastatic tumor biopsies, CTCs, and peripheral blood (PB) from 19 newly diagnosed MBC patients. CTCs were harvested using the ANGLE Parsortix microfluidics system to isolate cells based on size and deformability, independent of a priori knowledge of cell surface marker expression.

RESULTS

Gene expression separated CTCs, metastatic biopsies, and PB into distinct groups despite heterogeneity between patients and sample types. CTCs showed higher expression of immune oncology targets compared with corresponding metastases and PB. Predictive biomarker (n = 64) expression was highly concordant for CTCs and metastases. Repeat observation data post-treatment demonstrated changes in the activation of different biological pathways. Somatic single nucleotide variant analysis showed increasing mutational complexity over time.

CONCLUSION

We demonstrate that RNA-Seq of CTCs could serve as a surrogate biomarker for breast cancer macrometastasis and yield clinically relevant insights into disease biology and clinically actionable targets.