As an important trace element, iron is involved in a variety of physiological processes. In recent years, studies have found that the occurrence and development of tumors are closely related to abnormal iron metabolism, and the mode of action is obviously heterogeneous. Tumor cells need more iron to promote their survival and proliferation, but iron overload can also have adverse effects on tumor cells, such as ferroptosis. Ferroptosis is a special regulatory mechanism of cell death, which is different from other regulated cell death pathways. It mainly induces cell death through excessive accumulation of iron-dependent lipid peroxide and reactive oxygen species (ROS). Recent studies have found that in the blood system, tumor cells of lymphoma and multiple myeloma (MM) are more sensitive to ferroptosis and affect disease progression through a variety of mechanisms. In this review, the mechanisms of ferroptosis in some subtypes of lymphoma and MM are described in detail, and the correlation between ferroptosis of hematological tumor cells and the occurrence and development of hematological tumors is revealed, aiming to provide new ideas for the treatment of these hematological diseases.
Humans ; Iron/metabolism* ; Ferroptosis ; Multiple Myeloma/metabolism* ; Lymphoma/metabolism* ; Reactive Oxygen Species/metabolism* ; Lymphocytes

OBJECTIVE: To explore the role of semaphorin 4D (Sema4D) in immunoglobulin A (IgA) -mediated immune abnormalities in B lymphocytes of pediatric Henoch-Schonlein purpura (HSP). METHODS: One hundred HSP children admitted to Hengshui People's Hospital from January 2022 to January 2023 were selected as HSP group, and one hundred healthy children as control group. Sema4D expression was detected, and the relationship between Sema4D expression in children's serum and skin lesions and clinical characteristics of children was analyzed. Sema4D expression on the surface of lymphocytes of HSP children was detected. Different concentrations of human recombinant Sema4D protein was used to stimulate peripheral blood mononuclear cells in HSP children in vitro. The expression level of IgA in the supernatant was detected to verify whether Sema4D mediates immune abnormalities through IgA secreted by B lymphocytes. RESULTS: The Sema4D level in the HSP group was significantly higher than that in the control group (P <0.001). Sema4D level in HSP children with severe, renal involvement, and joint involvement was higher than those with mild to moderate disease, and no renal or joint involvement (all P <0.001). Compared with control group, IgA level, CD8 ⁺ T lymphocyte proportion, and CD19 ⁺ B lymphocyte proportion in the HSP group were significantly higher but CD4 ⁺ T lymphocyte proportion was lower (all P <0.001). The expression levels of Sema4D on the surface of CD4 ⁺ T lymphocytes, CD8 ⁺ T lymphocytes, and CD19 ⁺ B lymphocytes in the HSP group were significantly higher than those in the control group (all P <0.001). With the increase of human recombinant Sema4D protein concentration, the level of IgA expression in HSP children gradually increased (P <0.05). Correlation analysis showed that Sema4D was significantly positively correlated with IgA (r =0.667). CONCLUSION HSP children show high expression of Sema4D, especially on the surface of T and B lymphocytes. The shedding of Sema4D from membrane surface may stimulate B lymphocytes to secrete IgA by binding to CD72, leading to immune abnormalities.
Humans ; IgA Vasculitis/immunology* ; Semaphorins/metabolism* ; B-Lymphocytes/metabolism* ; Immunoglobulin A/immunology* ; Child ; Antigens, CD/metabolism* ; Male ; Female ; Child, Preschool

OBJECTIVE: To explore the effects and mechanism of Chinese medicine Liujunzi Decoction (LJZD) on regulating microbial flora in mice with asthma flora disorder. METHODS: Thirty BALB/c female mice were divided into control, model, LJZD [3.5 g/(kg•d), by gavage], dexamethasone [DXMS, 0.7 mg/(kg•d), intraperitoneal injection], and Clostridium butyricum [CB, 230 mg/(kg•d), by gavage] groups according to a random number table, 6 mice in each group. The asthma flora disorder mice model was induced with ovalbumin (OVA). Lung and gut lesions were analyzed by hematoxylin-eosin (HE) and periodic acid-Schiff (PAS) stainings. The secretory immunoglobulin A (sIgA) protein expression in lung and gut tissues was detected by Western blot. Flow cytometry was used to detect the relative counts of GATA binding protein 3 (GATA3)/type 2 innate lymphoid cells (ILC2) in lung and gut. The levels of inflammatory factors in lung and gut tissues were detected by enzyme-linked immunosorbent assay (ELISA). Chao1 and Shannon index were used to compare microbial abundance and diversity in alveolar lavage fluid and cecal contents. The similarity or difference in the composition of mice microbial communities was analyzed through cluster analysis. The serum short-chain fatty acids (SCFAs) content was detected by ultra performance liquid chromatograph mass spectrometer (LC-MS)/MS. RESULTS: The asthma flora disorder model mice showed obvious asthma-related symptoms, but LJZD treatment effectively alleviated these symptoms. LJZD restored alveolar wall thickening, airway inflammatory cell infiltration, gut tissue structure destruction, and inflammatory cell infiltration in asthma flora disorder mice. LJZD downregulated the sIgA protein expression in mice (P<0.05). Moreover, LJZD decreased the activation of GATA3/ILC2s in lung and gut tissue (P<0.01), and reduced the levels of interleukin (IL)-5, IL-33, IL-25, IL-9 and IL-13 (P<0.01). LJZD treatment returned the abundance of microbial species and the microbial community structure of alveolar lavage fluid and cecal content in asthma flora disorder mice to the normal state. The SCFAs content and body metabolism were also improved. CONCLUSION LJZD exerted anti-asthmatic effects by improving the microbial balance of lung-gut axis and affecting systemic metabolism, consequently regulating the GATA3/ILC2s axis to impact the lung inflammatory response.
Animals ; Asthma/pathology* ; GATA3 Transcription Factor/metabolism* ; Drugs, Chinese Herbal/therapeutic use* ; Gastrointestinal Microbiome/drug effects* ; Mice, Inbred BALB C ; Female ; Lung/drug effects* ; Homeostasis/drug effects* ; Inflammation/pathology* ; Lymphocytes/drug effects* ; Mice

OBJECTIVES: To investigate the inhibitory effect of pirfenidone (PFD) on growth of bladder cancer xenograft and its regulatory effect on Treg cells in tumor-bearing mice. METHODS: Thirty-two C57BL/6 mice bearing ectopic bladder tumors were randomized into control and PFD groups (n=16). In PFD group, PFD was administered orally at the daily dose of 500 mg/kg, and tumor growth and survival of the mice were monitored. After treatment for 21 days, the tumors and vital organs were harvested for analysis. Immunohistochemistry was used to assess CD3, CD4, CD8, and FOXP3 expressions in the tumors. Flow cytometry and RT-qPCR were used to analyze the percentage of CD4⁺CD25⁺FOXP3⁺ Treg cells and IL-2, IL-10, and IL-35 expressions in the tumors and spleens; organ damage of the mice was examined with HE staining. RESULTS: Compared with the control group, the PFD-treated mice exhibited significantly lower tumor growth rate with smaller tumor volumes at day 21, along with improved survival at day 28. Immunohistochemistry revealed no significant differences in the infiltration of CD3⁺ and CD8⁺ cells between the two groups, but the percentages of CD4⁺ and FOXP3⁺ cells were significantly lower in the tumors of PFD-treated mice. Flow cytometric analysis confirmed a decrease in CD4⁺CD25⁺FOXP3⁺ Treg cells in the tumors from PFD-treated mice, which also had reduced expression levels of IL-2, IL-10 and IL-35 mRNAs in the tumors. No significant differences were found in Treg cell populations or cytokine expressions in the spleen tissues between the two groups. HE staining showed obvious organ damage in neither of the groups. CONCLUSIONS PFD inhibits bladder cancer growth and enhances survival of tumor-bearing mice possibly by suppressing Treg cells in the tumor microenvironment.
Animals ; Urinary Bladder Neoplasms/drug therapy* ; Mice ; T-Lymphocytes, Regulatory/metabolism* ; Mice, Inbred C57BL ; Interleukins/metabolism* ; Interleukin-10/metabolism* ; Cell Line, Tumor ; Interleukin-2/metabolism* ; Xenograft Model Antitumor Assays ; Female

OBJECTIVES: To investigate the effect of cardiomyocytes-derived exosomes on lipopolysaccharide (LPS)-induced cardiomyocyte injury and its mechanism. METHODS: Exosomes isolated from rat cardiomyocytes with or without LPS treatment were co-cultured with rat lymphocytes. The lymphocytes with or without exosome treatment were co-cultured with LPS-induced rat cardiomyocytes for 48 h. Cardiomyocyte apoptosis was detected using flow cytometry, and the expressions of apoptosis marker proteins and the PI3K/AKT pathway proteins were detected using Western blotting. The effects of human recombinant IL-38 protein on apoptosis and protein expressions in LPS-induced cardiomyocytes were examined. RESULTS: Compared with normal cardiomyocyte-derived exosomes, the exosomes from LPS-induced cardiomyocytes significantly enhanced proliferation and increased mRNA and protein expression levels of IL-38 in rat lymphocytes. Bioinformatics analysis suggested that miR-1275 in the exosome played a key role in LPS-induced cardiomyocyte injury, and in dual luciferase reporter gene assay, miR-1275 mimics significantly increased luciferase activity of WT-IL-38. Co-culture with lymphocytes treated with exosomes from LPS-induced cardiomyocytes significantly inhibited apoptosis of LPS-induced cardiomyocytes. Treatment with recombinant IL-38 also effectively lowered apoptosis rate of LPS-induced cardiomyocytes, reduced cellular expression of Bax protein, and increased the protein expression levels of Bcl-2, p-PI3K and p-AKT. CONCLUSIONS miR-1275 in exosomes derived from LPS-induced cardiomyocytes mediates IL-38 up-regulation expression in lymphocytes to activate the PI3K/AKT pathway and inhibit LPS-induced cardiomyocyte apoptosis.
Apoptosis/drug effects* ; MicroRNAs/metabolism* ; Myocytes, Cardiac/metabolism* ; Animals ; Lipopolysaccharides ; Rats ; Exosomes/metabolism* ; Up-Regulation ; Interleukins/metabolism* ; Lymphocytes/cytology* ; Cells, Cultured ; Signal Transduction ; Coculture Techniques ; Phosphatidylinositol 3-Kinases/metabolism* ; Rats, Sprague-Dawley ; Humans ; Proto-Oncogene Proteins c-akt/metabolism*

OBJECTIVES: To investigate the efficacy of Qihuang Jianpi Zishen Granules (QJZ) for inhibiting renal B cell differentiation in MRL/lpr mice and explore its underlying mechanism. METHODS: Thirty 8-week-old female MRL/lpr mice were randomly divided into model group, QJZ group, prednisone (Pred) group, QJZ+Pred group, and AIM2 inhibitor group (n=6), with 6 8-week-old female C57BL/6 mice as the normal control group. After treatments with normal saline, QJZ, Pred, or AIM2 inhibitor for 8 weeks, the mice were examined for urinary total protein-to-creatinine ratio (TPCR) and albumin-to-creatinine ratio (ACR), serum creatinine (Cr) and blood urea nitrogen (BUN) levels, and renal histopathology (with HE, Masson, and PAS staining) and ultrastructural changes (with electron microscopy). ELISA, immunohistochemistry, immunofluorescence staining and flow cytometry were used to detect blood levels of anti-dsDNA antibodies, cytokines and chemokines, renal deposition of complement components C3 and C4, renal expressions of AIM2, CD19, CD27 and CD138, and changes in splenic B lymphocyte subsets. The effect of QJZ on the AIM2/Blimp-1/Bcl-6 signaling axis was examined using Western blotting. RESULTS: QJZ treatment significantly improved Cr, BUN, TPCR and ACR in MRL/lpr mice, ameliorated renal pathologies, reduced the expressions of ds-DNA, BAFF, IL-21, CXCL12, CXCL13, C3 and C4, and increased IL-10 levels. QJZ significantly downregulated renal expressions of the key B-cell transcription factors Blimp-1 and XBP-1, upregulated Bcl-6 and PAX5 expressions, inhibited B-cell differentiation, and lowered the expressions of AIM2, CD27, CD138 and CD69. Inhibition of AIM2 similarly reduced renal Blimp-1 and XBP-1 expressions, increased Bcl-6 and PAX5 levels, suppressed B-cell differentiation, decreased IgG production, reduced C3 and C4 deposition, and alleviated renal pathology in MRL/lpr mice. CONCLUSIONS QJZ inhibits B cell differentiation and alleviates renal damage in systemic lupus erythematosus possibly by suppressing the AIM2/Blimp-1/Bcl-6 signaling pathway.
Animals ; Drugs, Chinese Herbal/therapeutic use* ; Mice, Inbred MRL lpr ; Female ; Mice ; Mice, Inbred C57BL ; Cell Differentiation/drug effects* ; B-Lymphocytes/drug effects* ; Proto-Oncogene Proteins c-bcl-6/metabolism* ; Kidney/drug effects* ; DNA-Binding Proteins/metabolism* ; Signal Transduction ; Lupus Nephritis

Infiltration and activation of peripheral immune cells are critical in the progression of multiple sclerosis and its experimental animal model, experimental autoimmune encephalomyelitis (EAE). This study investigates the role of high mobility group box 1 (HMGB1) in oligodendrocyte precursor cells (OPCs) in modulating pathogenic T cells infiltrating the central nervous system through the blood-brain barrier (BBB) by using OPC-specific HMGB1 knockout (KO) mice. We found that HMGB1 released from OPCs promotes BBB disruption, subsequently allowing increased immune cell infiltration. The migration of CD4+ T cells isolated from EAE-induced mice was enhanced when co-cultured with OPCs compared to oligodendrocytes (OLs). OPC-specific HMGB1 KO mice exhibited lower BBB permeability and reduced immune cell infiltration into the CNS, leading to less damage to the myelin sheath and mitigated EAE progression. CD4+ T cell migration was also reduced when co-cultured with HMGB1 knock-out OPCs. Our findings reveal that HMGB1 secretion from OPCs is crucial for regulating immune cell infiltration and provides insights into the immunomodulatory function of OPCs in autoimmune diseases.
Animals ; Encephalomyelitis, Autoimmune, Experimental/metabolism* ; HMGB1 Protein/deficiency* ; Mice, Knockout ; Oligodendrocyte Precursor Cells/immunology* ; Mice, Inbred C57BL ; CD4-Positive T-Lymphocytes/immunology* ; Cell Movement ; Blood-Brain Barrier/immunology* ; Mice ; Myelin Sheath/pathology* ; Disease Models, Animal ; Coculture Techniques ; Oligodendroglia/metabolism* ; Female ; Cells, Cultured

Extensive epigenetic reprogramming involves in memory CD8+ T-cell differentiation. The elaborate epigenetic rewiring underlying the heterogeneous functional states of CD8+ T cells remains hidden. Here, we profile single-cell chromatin accessibility and map enhancer-promoter interactomes to characterize the differentiation trajectory of memory CD8+ T cells. We reveal that under distinct epigenetic regulations, the early activated CD8+ T cells divergently originated for short-lived effector and memory precursor effector cells. We also uncover a defined epigenetic rewiring leading to the conversion from effector memory to central memory cells during memory formation. Additionally, we illustrate chromatin regulatory mechanisms underlying long-lasting versus transient transcription regulation during memory differentiation. Finally, we confirm the essential roles of Sox4 and Nrf2 in developing memory precursor effector and effector memory cells, respectively, and validate cell state-specific enhancers in regulating Il7r using CRISPR-Cas9. Our data pave the way for understanding the mechanism underlying epigenetic memory formation in CD8+ T-cell differentiation.
CD8-Positive T-Lymphocytes/metabolism* ; Cell Differentiation ; Chromatin/immunology* ; Animals ; Mice ; Immunologic Memory ; Epigenesis, Genetic ; SOXC Transcription Factors/immunology* ; NF-E2-Related Factor 2/immunology* ; Mice, Inbred C57BL ; Gene Regulatory Networks ; Enhancer Elements, Genetic

Postmenopausal osteoporosis (PMOP) is a systemic metabolic bone disease caused by the decrease in estrogen levels after menopause. It leads to bone loss, microstructural damage, and an increased risk of fractures. Studies have found that the gut microbiota and its metabolites can regulate bone metabolism through the gut-bone axis and the gut-brain axis. As research progresses, PMOP has been found to be associated with gut microbiota dysbiosis and Th17/Treg imbalance. The gut microbiota is closely related to the development and differentiation of Treg and Th17 cells. Among them, the metabolites of the gut microbiota such as short-chain fatty acids (SCFAs) can regulate the differentiation of effector T cells by acting on molecular receptors on immune cells, thereby regulating the bone immune process. The multifaceted relationship among the gut microbiota, SCFAs, Th17/Treg cell-mediated bone immunity, and bone metabolism is eliciting attention from researchers. Through a review of existing literature, we have comprehensively summarized the effects of the gut microbiota and SCFAs on PMOP, especially from the perspective of Th17/Treg balance. Regulating this balance may provide new opportunities for PMOP treatment.
Humans ; Gastrointestinal Microbiome/immunology* ; Fatty Acids, Volatile/metabolism* ; Osteoporosis, Postmenopausal/immunology* ; Female ; T-Lymphocytes, Regulatory/metabolism* ; Th17 Cells/metabolism* ; Dysbiosis/immunology* ; Bone and Bones/metabolism*

BACKGROUND: T cell dysfunction, which includes exhaustion, anergy, and senescence, is a distinct T cell differentiation state that occurs after antigen exposure. Although T cell dysfunction has been a cornerstone of cancer immunotherapy, its potential in transplant research, while not yet as extensively explored, is attracting growing interest. Interferon regulatory factor 4 (IRF4) has been shown to play a pivotal role in inducing T cell dysfunction. METHODS: A novel ultra-low-dose combination of Trametinib and Rapamycin, targeting IRF4 inhibition, was employed to investigate T cell proliferation, apoptosis, cytokine secretion, expression of T-cell dysfunction-associated molecules, effects of mitogen-activated protein kinase (MAPK) and mammalian target of rapamycin (mTOR) signaling pathways, and allograft survival in both in vitro and BALB/c to C57BL/6 mouse cardiac transplantation models. RESULTS: In vitro , blockade of IRF4 in T cells effectively inhibited T cell proliferation, increased apoptosis, and significantly upregulated the expression of programmed cell death protein 1 (PD-1), Helios, CD160, and cytotoxic T lymphocyte-associated antigen (CTLA-4), markers of T cell dysfunction. Furthermore, it suppressed the secretion of pro-inflammatory cytokines interferon (IFN)-γ and interleukin (IL)-17. Combining ultra-low-dose Trametinib (0.1 mg·kg -1 ·day -1 ) and Rapamycin (0.1 mg·kg -1 ·day -1 ) demonstrably extended graft survival, with 4 out of 5 mice exceeding 100 days post-transplantation. Moreover, analysis of grafts at day 7 confirmed sustained IFN regulatory factor 4 (IRF4) inhibition, enhanced PD-1 expression, and suppressed IFN-γ secretion, reinforcing the in vivo efficacy of this IRF4-targeting approach. The combination of Trametinib and Rapamycin synergistically inhibited the MAPK and mTOR signaling network, leading to a more pronounced suppression of IRF4 expression. CONCLUSIONS Targeting IRF4, a key regulator of T cell dysfunction, presents a promising avenue for inducing transplant immune tolerance. In this study, we demonstrate that a novel ultra-low-dose combination of Trametinib and Rapamycin synergistically suppresses the MAPK and mTOR signaling network, leading to profound IRF4 inhibition, promoting allograft acceptance, and offering a potential new therapeutic strategy for improved transplant outcomes. However, further research is necessary to elucidate the underlying pharmacological mechanisms and facilitate translation to clinical practice.
Animals ; Mice ; Mice, Inbred BALB C ; Mice, Inbred C57BL ; Interferon Regulatory Factors/metabolism* ; Heart Transplantation/methods* ; T-Lymphocytes/immunology* ; Sirolimus/therapeutic use* ; Pyridones/therapeutic use* ; Graft Survival/drug effects* ; Pyrimidinones/therapeutic use* ; Cell Proliferation/drug effects* ; Apoptosis/drug effects* ; Male ; Signal Transduction/drug effects*