Objective To explore the regulatory effects of cytokines interleukin(IL)-1β,IL-6,tumor necrosis factor alpha(TNF-ɑ),gamma interferon(IFN-γ),granulocyte colony-stimulating factor(G-CSF),and granulocyte-macrophage colony-stimulating factor(GM-CSF)on spontaneous pyroptosis in neutrophils.Methods Neutrophils isolated from mouse bone marrow by density-gradient centrifugation were cultured <i>in vitroi> for 20 h with or without 10,50 or 100 ng/mL IL-1β,IL-6,IFN-γ,G-CSF or GM-CSF,or for 12 h with or without 1,10 or 50 ng/mL TNF-α.After incubation,cells were stained with annexin Ⅴ(AV)/propidium iodide(PI),and the proportions and absolute number of neutrophils undergoing different forms of cell death were determined by fluorescence microscopy combined with manual counting.Pyroptotic neutrophils were identified by cell morphology in conjunction with AV/PI staining.Flow cytometry with counting beads was employed to measure the proportions and number of AV/PI-stained Ly6g⁺neutrophils in different forms of cell death.Western blotting was employed to assess the cleavage and activation levels of cysteinyl aspartate-specific proteinase-3(caspase-3)and gasdermin E(GSDME).Results Treatment with IL-1β or IL-6 had no significant effect on the proportion or number of neutrophils undergoing spontaneous pyroptosis.After 12 h of treatment with TNF-α at 1,10,and 50 ng/mL,the proportions of pyroptotic neutrophils were(14.79±0.45)%,(19.99±3.02)%,and(20.66±1.99)%,respectively,higher than that[(10.22±1.12)%]in the untreated control(<i>Pi>=0.024,<i>Pi><0.001,and <i>Pi><0.001,respectively).Treatment with 10,50,and 100 ng/mL IFN-γ for 20 h reduced the proportion of pyroptotic neutrophils from(17.43±1.88)%to 12.00%(all <i>Pi><0.001).G-CSF at 10,50,and 100 ng/mL reduced the proportion of pyroptotic cells to around 6.00%and greatly inhibited the cleavage of both caspase-3 and GSDME.After 20 h of treatment with 10,50,and 100 ng/mL GM-CSF,the proportions of pyroptotic neutrophils decreased to(7.52±0.53)%,(5.27±2.30)%,and(0.64±1.11)%,respectively.Conclusions Neither IL-1β nor IL-6 affects GSDME-mediated spontaneous pyroptosis in neutrophils.TNF-ɑ induces spontaneous pyroptosis in neutrophils,whereas IFN-γ,G-CSF,and GM-CSF demonstrate inhibitory effects.
Pyroptosis/drug effects* ; Animals ; Neutrophils/cytology* ; Mice ; Cytokines/pharmacology* ; Interleukin-1beta/pharmacology* ; Granulocyte-Macrophage Colony-Stimulating Factor/pharmacology* ; Cells, Cultured ; Granulocyte Colony-Stimulating Factor/pharmacology* ; Tumor Necrosis Factor-alpha/pharmacology* ; Interferon-gamma/pharmacology* ; Interleukin-6/pharmacology*

Objective To explore the effect of miR-582-5p on Mycobacterium tuberculosis (Mtb)-infected macrophages by regulating dual specificity phosphatase 1 (DUSP1). Methods THP-1 macrophages were divided into six groups: control group, Mtb group, inhibitor-NC group, miR-582-5p inhibitor group, miR-582-5p inhibitor+si-NC group, and miR-582-5p inhibitor+si-DUSP1 group. QRT-PCR was applied to detect the gene expression of miR-582-5p and DUSP1 in cells. ELISA kit was used to detect the levels of interferon γ (IFN-γ), interleukin 6 (IL-6), tumor necrosis factor α (TNF-α), and interleukin 1β (IL-1β). CCK-8 method was applied to detect cell proliferation. Flow cytometry was applied to detect cell apoptosis rate. Western blot analysis was used to measure the protein expression levels of B-cell lymphoma 2 (Bcl2), Bcl2-associated X (BAX), and cleaved-caspase 3 (c-caspase-3) in cells. In addition, the target relationship between miR-582-5p and DUSP1 was verified. Results Compared with the control group, the expression of miR-582-5p, levels of IFN-γ, IL-6, TNF-α, IL-1β, bacterial load and OD450 values (24 h, 48 h), and the protein expression of Bcl2 in macrophages were higher in the Mtb group, while the mRNA expression of DUSP1, apoptosis rate, and the protein expression levels of c-caspase-3, BAX and DUSP1 were lower. Compared with the Mtb group and the inhibitor-NC group, the above-mentioned indicators in the miR-582-5p inhibitor group were partially reversed. Down-regulation of DUSP1 expression partially reversed the inhibitory effect of down-regulation of miR-582-5p expression on Mtb-infected macrophages. Conclusion Inhibiting the expression of miR-582-5p can up-regulate DUSP1, thereby inhibiting the proliferation and inflammatory response of Mtb-infected macrophages and promoting cell apoptosis.
Humans ; Macrophages/metabolism* ; Dual Specificity Phosphatase 1/metabolism* ; MicroRNAs/metabolism* ; Mycobacterium tuberculosis/physiology* ; Tuberculosis/microbiology* ; Apoptosis/genetics* ; THP-1 Cells ; Cell Proliferation/genetics* ; Interferon-gamma/genetics* ; Tumor Necrosis Factor-alpha/genetics* ; Interleukin-1beta/genetics*

Objective To explore the effect of the knockdown of transmembrane 9 superfamily protein member 2 (TM9SF2) on the replication of vesicular stomatitis virus (VSV), and investigate its role in the mechanism of antiviral innate immunity. Methods Small interfering RNA (siRNA) was used to knock down the TM9SF2 gene in human non-small cell lung cancer A549 cells. The CCK-8 method was used to assess cell proliferation. A VSV-green fluorescent protein (VSV-GFP) infected cell model was established. The plaque assay was used to measure the viral titer in the supernatant. RT-qPCR and Western blotting were employed to quantify the mRNA and protein levels of VSV genome replication in A549 cells following VSV infection, as well as the expression of interferon β (IFN-β) mRNA and interferon regulatory factor 3 (IRF3) protein phosphorylation following polyinosinic-polycytidylic acid (poly(I:C)) stimulation. Results Compared to the negative control, the knockdown of TM9SF2 exhibited a significant effect, with no observed impact on A549 cell proliferation. The VSV-GFP infected A549 cell model was successfully established. After viral stimulation, fluorescence intensity was reduced following TM9SF2 knockdown, and the mRNA and protein levels of VSV were significantly downregulated. The viral titer of VSV was decreased. After poly(I:C) stimulation, TM9SF2 knockdown significantly upregulated the mRNA level of IFN-β and the phosphorylation level of IRF3 protein. Conclusion The knockdown of TM9SF2 inhibits the replication of vesicular stomatitis virus, and positively regulates the type I interferon signaling pathway, thus enhancing the host's antiviral innate immune response.
Humans ; Virus Replication/genetics* ; Signal Transduction ; Membrane Proteins/metabolism* ; A549 Cells ; Vesiculovirus/physiology* ; Interferon-beta/metabolism* ; Interferon Regulatory Factor-3/genetics* ; Interferon Type I/metabolism* ; Vesicular Stomatitis/immunology* ; Gene Knockdown Techniques ; Vesicular stomatitis Indiana virus/physiology* ; RNA, Small Interfering/genetics*

Objectives To investigate interleukin 36γ (IL-36γ) expression, and analyze the influence of IL-36γ to CD8⁺ T cell activity in chronic obstructive pulmonary diseases (COPD) patients with secondary fungal pneumonia. Methods Peripheral blood was collected from 47 COPD patients, 39 COPD patients with secondary fungal pneumonia, and 20 controls. Bronchial alveolar lavage fluid (BALF) was isolated from 27 COPD patients with secondary fungal pneumonia. CD8⁺ T cells were purified. The levels of four IL-36 isoforms in plasma and BALF were measured by enzyme linked immunosorbent assay (ELISA). CD8⁺ T cells were stimulated with recombinant human IL-36γ. The levels of interferon γ(IFN-γ), tumor necrosis factor α(TNF-α), perforin and granzyme B in the cultured supernatants were measured by ELISA. Recombinant human IL-36γ-stimulated CD8⁺ T cells were co-cultured with NCI-H1882 cells in either direct cell-to-cell contact or Transwell^TM manner. The levels of IFN-γ, TNF-α, and lactate dehydrogenase in the cultured supernatants were assessed. The percentage of target cell death was calculated. Results Plasma IL-36α, IL-36β, and IL-36γ levels were significantly elevated in both COPD group and COPD with secondary fungal pneumonia group compared with those in control group. However, only plasma IL-36γ level was higher in COPD with secondary fungal pneumonia group than that in COPD group [(200.11±99.95)pg/mL vs (53.03±87.18)pg/mL, P=0.023]. There was no remarkable difference in plasma IL-36 receptor antagonist level among three groups. IL-36γ level in BALF from infectious site was higher than that from non-infectious site in COPD with secondary fungal pneumonia group [(305.82±59.60)pg/mL vs (251.93±76.01)pg/mL, P=0.011]. IL-36γ stimulation enhanced IFN-γ, TNF-α, perforin and granzyme B secreted by CD8⁺ T cells. When IL-36γ-stimulated CD8⁺ T cells were directly mixed with NCI-H1882 cells for co-culture, the percentage of cell death was increased [(16.06±3.67)% vs (11.47±2.36)%, P=0.002]. When using Transwell^TM plate for non-contact co-culture, IL-36γ-stimulated CD8⁺ T cell-mediated death of NCI-H1882 cells showed no significant difference compared to that without stimulation [(4.77±0.78)% vs (4.99±0.92)%, P=0.554]. Conclusion IL-36γ level in plasma and infectious site is elevated in COPD patients with secondary fungal pneumonia, which enhances the cytotoxicity of CD8⁺ T cells in peripheral blood and infectious microenviroment.
Humans ; Pulmonary Disease, Chronic Obstructive/complications* ; CD8-Positive T-Lymphocytes/metabolism* ; Male ; Female ; Aged ; Middle Aged ; Interferon-gamma/metabolism* ; Interleukin-1/metabolism* ; Tumor Necrosis Factor-alpha/metabolism* ; Lung Diseases, Fungal/complications* ; Bronchoalveolar Lavage Fluid/chemistry* ; Perforin/metabolism* ; Pneumonia/immunology* ; Granzymes/metabolism*

Objective To investigate the role and mechanism of the zinc finger protein Kruppel-like transcription factor 9 (KLF9) in the stimulation of type I interferon expression induced by herpes simplex virus type 1 (HSV-1) in macrophages. Methods Agarose Gel electrophoresis, quantitative real-time PCR (qRT-PCR) and western blot analyses were employed to detect the KLF9 relative expression in bone marrow-derived macrophages (BMDMs) from Klf9^-/- (gKO) mice and wild-type (WT) mice. RNA-seq analysis was utilized to identify the potential targeted genes upon HSV-1 stimulation in BMDMs. ELISA was used to measure the potent of IFN-β in the supernatant of BMDMs derived from gKO and WT mice after HSV-1 stimulation. qRT-PCR analysis was employed to further confirm the changes of Ifnb1 and interferon-stimulated gene (ISG) such as interferon-induced protein with tetratricopeptide repeats 1 (Ifit1), interferon-stimulated exonuclease gene 20 (Isg20), cholesterol 25-hydroxylase (Ch25h) and 2'-5' oligoadenylate synthetase-like 1 (Oasl1). Western blot was used to detect the expression of phosphorylated interferon regulatory factor-3 (p-IRF3), IRF3, phosphorylated interferon regulatory factor-7 (p-IRF7), IRF7, phosphorylated nuclear factor-kappa B p65 (p-NF-κB p65) and NF-κB p65. CUT-Tag and ChIP-qPCR assay were utilized to confirm the binding region of KLF9 in Ifnb1. Results The KLF9 expression was significantly decreased in BMDMs from gKO mice compared with that from WT mice. The RNA-seq analysis showed that Klf9 deletion in BMDMs resulted in an impaired type I interferon signaling pathway. The qRT-PCR analysis revealed that Klf9 deletion in BMDMs led to a significant decrease of Ifnb1 and ISG such as Ifit1, Ch25h and Oasl1 except Isg20. Moreover, ELISA revealed that Klf9 knockout in BMDMs resulted in a significant decrease of IFN-β secreted from BMDMs. Mechanistically, KLF9 directly binds to the promoter of Ifnb1. Conclusion KLF9 is essential for macrophages to resist HSV-1 infection.
Animals ; Kruppel-Like Transcription Factors/physiology* ; Interferon-beta/metabolism* ; Macrophages/virology* ; Mice ; Herpesvirus 1, Human/physiology* ; Mice, Knockout ; Signal Transduction ; Mice, Inbred C57BL ; Interferon Regulatory Factor-3/genetics* ; Interferon Regulatory Factor-7/genetics* ; Gene Expression Regulation

Objective To characterize the properties of Hepa1-6-derived microparticles (Hepa1-6-MPs), investigate their stimulatory effects on dendritic cells (DCs) and their cellular uptake pathways, and explore the specific cytotoxic effects of CD8⁺ T cells induced by Hepa1-6-MP-loaded DCs on hepatoma cell lines, with the aim of developing a novel immunotherapeutic model for hepatocellular carcinoma (HCC). Methods The isolated Hepa1-6-MPs were identified using Western blotting, transmission electron microscopy (TEM) and dynamic light scattering (DLS). Flow cytometry was used to assess the uptake pathways of Hepa1-6-MPs by DCs. Subsequently, enzyme-linked immunosorbent assay (ELISA) was used to measure the effects of Hepa1-6-MP-loaded DCs on the release levels of tumor necrosis factor α(TNF-α) and interferon γ(IFN-γ) into the supernatant of CD8⁺ T cells. Lactate dehydrogenase (LDH) tests were conducted to evaluate the cytotoxic effects of CD8⁺ T cells stimulated by Hepa1-6-MP-loaded DCs on hepatoma cells. Results The morphology, size and protein markers of Hepa1-6-MPs met the established criteria. Hepa1-6-MPs enhanced the expression of DC maturation markers CD80 and CD86, and were internalized by DCs via clathrin-mediated endocytosis and phagocytosis pathways. Subsequently, Hepa1-6-MP-loaded DCs stimulated CD8⁺ T cells to release high levels of TNF-α and IFN-γ, which induced their specific cytotoxicity against HCC cells. Conclusion These findings suggest that Hepa1-6-MP-loaded DCs may be a promising HCC immunotherapeutic tool.
Carcinoma, Hepatocellular/therapy* ; Liver Neoplasms/therapy* ; Dendritic Cells/immunology* ; Humans ; Cancer Vaccines/immunology* ; CD8-Positive T-Lymphocytes/immunology* ; Cell Line, Tumor ; Tumor Necrosis Factor-alpha/immunology* ; Interferon-gamma/immunology* ; Cell-Derived Microparticles/immunology* ; Animals

PURPOSE: To investigate the regulatory role of nerve injury-induced protein 1 (NINJ1) in the anti-inflammatory function of human umbilical cord mesenchymal stem cells (hUC-MSCs) co-stimulated by interferon-gamma (IFN-γ) and tumor necrosis factor-alpha (TNF-α). METHODS: hUC-MSCs were expanded in vitro using standard protocols, with stem cell characteristics confirmed by flow cytometry and multilineage differentiation assays. The immunomodulatory properties and cellular activity of cytokine-co-pretreated hUC-MSCs were systematically evaluated via quantitative reverse transcription RT-qPCR, lymphocyte proliferation suppression assays, and Cell Counting Kit-8 viability tests. Transcriptome sequencing, Western blotting and small interfering RNA interference were integrated to analyze the regulatory mechanisms of NINJ1 expression. Functional roles of NINJ1 in pretreated hUC-MSCs were elucidated through gene silencing combined with lactate dehydrogenase release assays, Annexin V/Propidium Iodide apoptosis analysis, macrophage co-culture models, and cytokine Enzyme-Linked Immunosorbent Assay. Therapeutic efficacy was validated in a cecal ligation and puncture-induced septic mouse model: 80 mice were randomly allocated into 4 experimental groups (n=20/group): sham group (laparotomy without cecal ligation); phosphate-buffered saline-treated group (cecal ligation and puncture (CLP) + 0.1 mL phosphate-buffered saline); hUC-MSCs (small interfering RNA (siRNA)-interferon-gamma and tumor necrosis factor-alpha co-stimulation (IT))-treated group (CLP + hUC-MSCs transfected with scrambled siRNA); and hUC-MSCs (siNINJ1-IT)-treated group (CLP + hUC-MSCs with NINJ1-targeting siRNA). RESULTS: hUC-MSCs demonstrated compliance with International Society for Cellular Therapy criteria, confirming their stem cell identity. IFN-γ/TNF-α co-pretreatment enhanced the immunosuppressive capacity of hUC-MSCs, accompanied by the reduction of cellular viability, while concurrently upregulating pro-inflammatory cytokines such as interleukin-6 and interleukin-1β. This co-stimulation significantly elevated NINJ1 expression in hUC-MSCs, whereas genetic silencing of NINJ1 effectively suppressed pro-inflammatory cytokine production and attenuated damage-associated molecular patterns release through inhibition of programmed plasma membrane rupture. Furthermore, the NINJ1 interference potentiated the ability of cytokine-pretreated hUC-MSCs to suppress LPS-induced pro-inflammatory responses in RAW264.7 macrophages. In cecal ligation and puncture-induced sepsis model, NINJ1-silenced hUC-MSCs exhibited enhanced therapeutic efficacy, manifested by reduced systemic inflammation and multi-organ damage. CONCLUSION Our findings shed new light on the immunomodulatory functions of cytokine-primed MSCs, offering groundbreaking insights for developing MSC-based therapies against inflammatory diseases via interfering the expression of NINJ1.
Mesenchymal Stem Cells/drug effects* ; Animals ; Interferon-gamma/pharmacology* ; Tumor Necrosis Factor-alpha/pharmacology* ; Humans ; Mice ; Umbilical Cord/cytology* ; Cells, Cultured ; Apoptosis ; Male

OBJECTIVE: To explore the expression and clinical significance of programmed death receptor 1 (PD-1), Th1, Th2, and Th17 cytokines in multiple myeloma (MM). METHODS: A total of 76 MM patients treated in the Tengzhou Central People's Hospital from May 2021 to May 2023 were collected as MM group, and 48 healthy individuals who underwent physical examination during the same period were included as control group. The expression of PD-1 on the surface of CD4⁺ and CD8⁺ T cells and the levels of serum Th1 cytokines ［interleukin (IL) -2, interferon γ (IFN-γ), tumor necrosis factor α (TNF-α)］, Th2 cytokines (IL-4, IL-6, IL-10) and Th17 cytokines (IL-17) were detected in the two groups. Spearman correlation was used to examine the relationship between PD-1, Th1, Th2 and Th17 cytokines and clinical stage and immune typing of MM patients. Multivariate logistic regression analysis was used to analyze the related factors affecting the efficacy of chemotherapy in MM patients, and the factors were tested for multicollinearity. Receiver operating characteristic (ROC) curve was drawn to analyze the predictive value of PD-1, Th1, Th2 and Th17 cytokines in chemotherapy efficacy of MM patients. RESULTS: The levels of CD4⁺T PD-1, CD8⁺T PD-1, IL-4, IL-6, IL-10, and IL-17 in the MM group were higher than those in the control group, while the levels of IL-2, IFN-γ, and TNF-α were lower (all <i>Pi> <0.001). The levels of CD4⁺T PD-1, CD8⁺T PD-1, IL-4, IL-6, IL-10, and IL-17 in R-ISS stage III patients were higher than those in stage II and I patients, and the levels in stage II patients were higher than those in stage I patients (all <i>Pi> <0.05). The IL-2 level in R-ISS stage III patients was lower than that in stage II and I patients, and IL-2 level in R-ISS stage II patients was lower than that in stage I patients (all <i>Pi> <0.05). The levels of CD4⁺T PD-1, CD8⁺T PD-1, IL-4, IL-6, IL-10, and IL-17 in IgG patients were higher than those in IgA, light chain, and non secretory patients, while the level of IL-2 was lower (all <i>Pi> <0.05). Correlation analysis showed that CD4⁺T PD-1, CD8⁺T PD-1, IL-4, IL-6, IL-10, and IL-17 were positively correlated with R-ISS staging in MM patients (<i>ri> =0.623, 0.635, 0.728, 0.330, 0.742, 0.412), and negatively correlated with immune classification (<i>ri> =-0.664, -0.756, -0.642, -0.479, -0.613, -0.323). IL-2 was negatively correlated with R-ISS staging in MM patients (<i>ri> =-0.280), and positively correlated with immune classification (<i>ri> =0.483). The levels of CD4⁺T PD-1, CD8⁺T PD-1, IL-4, IL-6, IL-10, and IL-17 in the non-remission group were higher than those in the remission group, while the level of IL-2 was lower (all <i>Pi> <0.001). Multivariate logistic regression analysis showed that the increased CD4⁺T PD-1, CD8⁺T PD-1, IL-4, IL-6, IL-10 and IL-17 were risk factors for the efficacy of chemotherapy in MM patients (<i>ORi> >1, <i>Pi> <0.05), while the increased IL-2 was a protective factor (<i>ORi> < 1, <i>Pi> <0.05). The results of multicollinearity test showed that the tolerance of the seven factors included was between 0.714-0.885, and the variance inflation factor was between 1.130-1.400. There was no multicollinearity. The ROC curve analysis results showed that the area under the curve for the combined prediction of chemotherapy efficacy in MM patients by the above 7 factors was 0.942, with specificity of 0.741 and sensitivity of 0.909. CONCLUSION The expression levels of PD-1 on the surface of CD4⁺ and CD8⁺ T cells and serum Th2 and Th17 cytokines in MM patients are high, while Th1 cytokines are low. PD-1, Th1, Th2, and Th17 cytokines are related to clinical stage and immune classification of MM patients. The combined detection of these indicators can help predict the chemotherapy efficacy of MM patients.
Humans ; Programmed Cell Death 1 Receptor/metabolism* ; Multiple Myeloma/blood* ; Cytokines/metabolism* ; Th17 Cells/metabolism* ; Th1 Cells/metabolism* ; Th2 Cells/metabolism* ; Female ; Male ; Interleukin-10 ; Interferon-gamma ; Middle Aged ; Interleukin-17 ; Interleukin-2 ; Interleukin-4 ; Tumor Necrosis Factor-alpha ; Interleukin-6 ; Aged

OBJECTIVES: To investigate the mechanism by which transforming growth factor‑β (TGF‑β) regulates major histocompatibility complex class I (MHC-I) expression in hepatocellular carcinoma (HCC) cells and its role in immune evasion of HCC. METHODS: HCC cells treated with TGF‑β alone or in combination with SB-431542 (a TGF-β type I receptor inhibitor) were examined for changes in MHC-I expression using RT-qPCR and Western blotting. A RNA interference experiment was used to explore the role of miR-23a-3p/IRF1 signaling in TGF‑β‑mediated regulation of MHC-I. HCC cells with different treatments were co-cultured with human peripheral blood mononuclear cells (PBMCs), and the changes in HCC cell proliferation was assessed using CCK-8 and colony formation assays. T-cell cytotoxicity in the co-culture systems was assessed with lactate dehydrogenase (LDH) release and JC-1 mitochondrial membrane potential assays, and T-cell activation was evaluated by flow cytometric analysis of CD69 cells and ELISA for TNF-α secretion. RESULTS: TGF‑β treatment significantly suppressed MHC-I expression in HCC cells and reduced T-cell activation, leading to increased tumor cell proliferation and decreased HCC cell death in the co-culture systems. Mechanistically, TGF-β upregulated miR-23a-3p, which directly targeted IRF1 to inhibit MHC-I transcription. Overexpression of miR-23a-3p phenocopied TGF‑β‑induced suppression of IRF1 and MHC-I. CONCLUSIONS We reveal a novel immune escape mechanism of HCC, in which TGF‑β attenuates T cell-mediated antitumor immunity by suppressing MHC-I expression through the miR-23a-3p/IRF1 signaling axis.
Humans ; MicroRNAs/genetics* ; Carcinoma, Hepatocellular/metabolism* ; Liver Neoplasms/metabolism* ; Interferon Regulatory Factor-1/metabolism* ; Transforming Growth Factor beta/metabolism* ; Signal Transduction ; Histocompatibility Antigens Class I/metabolism* ; Cell Line, Tumor ; Tumor Escape ; Coculture Techniques

Direct conversion of cardiac fibroblasts (CFs) to cardiomyocytes (CMs) in vivo to regenerate heart tissue is an attractive approach. After myocardial infarction (MI), heart repair proceeds with an inflammation stage initiated by monocytes infiltration of the infarct zone establishing an immune microenvironment. However, whether and how the MI microenvironment influences the reprogramming of CFs remains unclear. Here, we found that in comparison with cardiac fibroblasts (CFs) cultured in vitro, CFs that transplanted into infarct region of MI mouse models resisted to cardiac reprogramming. RNA-seq analysis revealed upregulation of interferon (IFN) response genes in transplanted CFs, and subsequent inhibition of the IFN receptors increased reprogramming efficiency in vivo. Macrophage-secreted IFN-β was identified as the dominant upstream signaling factor after MI. CFs treated with macrophage-conditioned medium containing IFN-β displayed reduced reprogramming efficiency, while macrophage depletion or blocking the IFN signaling pathway after MI increased reprogramming efficiency in vivo. Co-IP, BiFC and Cut-tag assays showed that phosphorylated STAT1 downstream of IFN signaling in CFs could interact with the reprogramming factor GATA4 and inhibit the GATA4 chromatin occupancy in cardiac genes. Furthermore, upregulation of IFN-IFNAR-p-STAT1 signaling could stimulate CFs secretion of CCL2/7/12 chemokines, subsequently recruiting IFN-β-secreting macrophages. Together, these immune cells further activate STAT1 phosphorylation, enhancing CCL2/7/12 secretion and immune cell recruitment, ultimately forming a self-reinforcing positive feedback loop between CFs and macrophages via IFN-IFNAR-p-STAT1 that inhibits cardiac reprogramming in vivo. Cumulatively, our findings uncover an intercellular self-stimulating inflammatory circuit as a microenvironmental molecular barrier of in situ cardiac reprogramming that needs to be overcome for regenerative medicine applications.
Animals ; Mice ; Macrophages/immunology* ; Fibroblasts/cytology* ; Cellular Reprogramming ; STAT1 Transcription Factor/genetics* ; Signal Transduction ; Interferon-beta/genetics* ; Myocardial Infarction/pathology* ; Myocytes, Cardiac/cytology* ; Mice, Inbred C57BL ; GATA4 Transcription Factor/genetics* ; Male ; Cells, Cultured