An effective therapeutic regimen for hepatic fibrosis requires a deep understanding of the pathogenesis mechanism. Hepatic fibrosis is characterized by activated hepatic stellate cells (aHSCs) with an excessive production of extracellular matrix. Although promoted activation of HSCs by M2 macrophages has been demonstrated, the molecular mechanism involved remains ambiguous. Herein, we propose that the vitamin D receptor (VDR) involved in macrophage polarization may regulate the communication between macrophages and HSCs by changing the functions of exosomes. We confirm that activating the VDR can inhibit the effect of M2 macrophages on HSC activation. The exosomes derived from M2 macrophages can promote HSC activation, while stimulating VDR alters the protein profiles and reverses their roles in M2 macrophage exosomes. Smooth muscle cell-associated protein 5 (SMAP-5) was found to be the key effector protein in promoting HSC activation by regulating autophagy flux. Building on these results, we show that a combined treatment of a VDR agonist and a macrophage-targeted exosomal secretion inhibitor achieves an excellent anti-hepatic fibrosis effect. In this study, we aim to elucidate the association between VDR and macrophages in HSC activation. The results contribute to our understanding of the pathogenesis mechanism of hepatic fibrosis, and provide potential therapeutic targets for its treatment.
Humans ; Hepatic Stellate Cells/pathology* ; Receptors, Calcitriol ; Liver Cirrhosis/pathology* ; Macrophages/metabolism*

Post-amputation pain causes great suffering to amputees, but still no effective drugs are available due to its elusive mechanisms. Our previous clinical studies found that surgical removal or radiofrequency treatment of the neuroma at the axotomized nerve stump effectively relieves the phantom pain afflicting patients after amputation. This indicated an essential role of the residual nerve stump in the formation of chronic post-amputation pain (CPAP). However, the molecular mechanism by which the residual nerve stump or neuroma is involved and regulates CPAP is still a mystery. In this study, we found that nociceptors expressed the mechanosensitive ion channel TMEM63A and macrophages infiltrated into the dorsal root ganglion (DRG) neurons worked synergistically to promote CPAP. Histology and qRT-PCR showed that TMEM63A was mainly expressed in mechanical pain-producing non-peptidergic nociceptors in the DRG, and the expression of TMEM63A increased significantly both in the neuroma from amputated patients and the DRG in a mouse model of tibial nerve transfer (TNT). Behavioral tests showed that the mechanical, heat, and cold sensitivity were not affected in the Tmem63a^-/- mice in the naïve state, suggesting the basal pain was not affected. In the inflammatory and post-amputation state, the mechanical allodynia but not the heat hyperalgesia or cold allodynia was significantly decreased in Tmem63a^-/- mice. Further study showed that there was severe neuronal injury and macrophage infiltration in the DRG, tibial nerve, residual stump, and the neuroma-like structure of the TNT mouse model, Consistent with this, expression of the pro-inflammatory cytokines TNF-α, IL-6, and IL-1β all increased dramatically in the DRG. Interestingly, the deletion of Tmem63a significantly reduced the macrophage infiltration in the DRG but not in the tibial nerve stump. Furthermore, the ablation of macrophages significantly reduced both the expression of Tmem63a and the mechanical allodynia in the TNT mouse model, indicating an interaction between nociceptors and macrophages, and that these two factors gang up together to regulate the formation of CPAP. This provides a new insight into the mechanisms underlying CPAP and potential drug targets its treatment.
Animals ; Mice ; Amputation, Surgical ; Chronic Pain/pathology* ; Disease Models, Animal ; Ganglia, Spinal/pathology* ; Hyperalgesia/etiology* ; Ion Channels/metabolism* ; Macrophages ; Neuroma/pathology*

OBJECTIVES: This study aimed to explore the functions and potential regulatory targets of local macrophages in nonalcoholic fatty liver combined with Porphyromonas gingivalis (P. gingivalis)infection. METHODS: Single-cell RNA sequencing was used to analyze the phenotypes and functional changes in various cells in the liver tissue of nonalcoholic steatohepatitis (NASH) mice fed with P. gingivalis. Real-time polymerase chain reaction (RT-PCR), enzyme-linked immunosorbent assay, and immunofluorescence staining were applied to observe the inflammation and expression levels of macrophage antigen presenting functional markers in the NASH liver. Oil red staining was performed to observe the accumulation of local adipose tissue in the NASH liver. Results were verified through RT-PCRand RNA sequencing using P. gingivalis-lipopolysaccharide treated mouse peritoneal macrophages. RESULTS: In comparison with healthy livers with Kupffer cells, the NASH liver combined with P. gingivalis infection-related macrophages showed significant heterogeneity. C1qb, C1qc, Mafb, Apoe, and Cd14 were highly expressed, but Cd209a, H2-Aa, H2-Ab1, and H2-DMb1, which are related to the antigen presentation function, were weakly expressed. Further in vivo and in vitro investigations indicated that the activation and infiltration of these macrophages may be due to local P. gingivalis-lipopolysaccharide accumulation. CONCLUSIONS P. gingivalis-lipopolysaccharide induces a local macrophage immunotolerance phenotype in nonalcoholic fatty liver, which may be the key mechanism of periodontitis pathogen infection that promotes NASH inflammation and pathogenesis. This study further clarifies the dysfunction and regulatory mechanisms of macrophages in the pathogenesis of P. gingivalis-infected NASH, thereby providing potential therapeutic targets for its clinical treatment.
Mice ; Animals ; Non-alcoholic Fatty Liver Disease/pathology* ; Kupffer Cells/pathology* ; Porphyromonas gingivalis ; Lipopolysaccharides/metabolism* ; Inflammation/pathology* ; Macrophages/metabolism* ; Mice, Inbred C57BL

Nonalcoholic fatty liver disease (NAFLD) is a type of metabolic stress liver injury that is closely associated with insulin resistance and genetic susceptibility. The continuum of liver injury in NAFLD can range from nonalcoholic fatty liver (NAFL) to nonalcoholic steatohepatitis (NASH) and even lead to cirrhosis and liver cancer. The pathogenesis of NAFLD is complicated. Pro-inflammatory cytokines, lipotoxicity, and gut bacterial metabolites play a key role in activating liver-resident macrophages (Kupffer cells, KCs) and recruiting circulating monocyte-derived macrophages (MoDMacs) to deposit fat in the liver. With the application of single-cell RNA-sequencing, significant heterogeneity in hepatic macrophages has been revealed, suggesting that KCs and MoDMacs located in the liver exert distinct functions in regulating liver inflammation and NASH progression. This study focuses on the role of macrophage heterogeneity in the development and occurrence of NAFLD and NASH, in view of the fact that innate immunity plays a key role in the development of NAFLD.
Humans ; Non-alcoholic Fatty Liver Disease/pathology* ; Liver/pathology* ; Macrophages/metabolism* ; Liver Cirrhosis/complications* ; Disease Progression

Objective: To investigate the differences of immune microenvironment between stage T1N3 and stage T3N0 breast cancer patients and explore the relationship between M1 macrophage infiltration and lymph node metastasis in breast cancer. Methods: Clinical information and RNA-sequencing (RNA-Seq) expression data of stage T1N3 (n=9) and stage T3N0 (n=11) breast cancer patients were extracted from Molecular Taxonomy of Breast Cancer International Consortium (METABRIC) databases. Using CIBERSORT, the proportions of 22 types of immune cells were calculated, and then the differences of immune cell infiltration between stage T1N3 and T3N0 patients were compared. From 2011 to 2022, pathologic specimens were collected from breast cancer patients who underwent curative resection at the Cancer Hospital, Chinese Academy of Medical Sciences, including 77 at stage T1N3 and 58 at stage T3N0.The METABRIC database analysis results were verified by examining the density of M1 macrophages in tissues using dual-staining immunohistochemistry. Results: METABRIC data analysis showed M1 macrophage was the highest proportion, 15.85% in stage T1N3 breast cancer; M2 macrophage was the highest proportion, 13.07% in stage T3N0 breast cancer.M1 macrophage proportions were statistically different between patients with stage T1N3 and stage T3N0 (P=0.010). The dual-staining immunohistochemistry analysis of breast cancer tissues showed M1 macrophage density (median) of 62.0 and 38.0 cells/mm(2) for stage T1N3 and T3N0, respectively. The difference was statistically significant (P=0.002). Conclusion: The density of M1 macrophages is notably higher in stage T1N3 patients and is associated with lymph node metastasis.
Humans ; Female ; Breast Neoplasms/pathology* ; Lymphatic Metastasis/pathology* ; Macrophages/metabolism* ; Tumor Microenvironment

The pathogenesis of inflammatory bowel disease (IBD) is not fully elucidated. However, it has been considered that inflammatory macrophages may be involved in the imbalance of the intestinal mucosal immunity to regulate several signaling pathways, leading to IBD progression. The ratio of M1 to M2 subtypes of activated macrophages tends to increase in the inflamed intestinal section. There are challenges in the diagnosis and treatment of IBD, such as unsatisfactory specificity of imaging findings, low drug accumulation in the intestinal lesions, unstable therapeutic efficacy, and drug-related systemic toxicity. Recently developed nanoparticles may provide a new approach for the diagnosis and treatment of IBD. Nanoparticles targeted to macrophages can be used as contrast agents to improve the imaging quality or used as a drug delivery vector to increase the therapeutic efficiency of IBD. This article reviews the research progress on macrophage-targeting nanoparticles for the diagnosis and treatment of IBD to provide a reference for further research and clinical application.
Humans ; Inflammatory Bowel Diseases/therapy* ; Intestines ; Macrophages/metabolism* ; Intestinal Mucosa/pathology* ; Nanoparticles

OBJECTIVE: To explore the mechanism of effects of total saponin fraction from Dioscorea Nipponica Makino (TSDN) on M1/M2 polarization of monocytes/macrophages and arachidonic acid (AA) pathway in rats with gouty arthritis (GA). METHODS: Seventy-two Sprague Dawley rats were randomly divided into 4 groups (n=18 in each): normal, model, TSDN at 160 mg/kg, and celecoxib at 43.3 mg/kg. Monosodium urate crystal (MSU) was injected into the rats' ankle joints to induce an experimental GA model. Blood and tissue samples were collected on the 3rd, 5th, and 8th days of drug administration. Histopathological changes in the synovium of joints were observed via hematoxylin and eosin (HE) staining. The expression levels of arachidonic acid (AA) signaling pathway were assessed via real-time polymerase chain reaction (qPCR) and Western blot. Flow cytometry was used to determine the proportion of M1 and M2 macrophages in the peripheral blood. An enzyme-linked immunosorbent assay (ELISA) was used to detect interleukine (IL)-1 β, tumor necrosis factor-alpha (TNF-α), IL-4, IL-10, prostaglandin E₂ (PGE₂), and leukotriene B4 (LTB4). RESULTS: HE staining showed that TSDN improved the synovial tissue. qPCR and Western blot showed that on the 3rd, 5th and 8th days of drug administration, TSDN reduced the mRNA and protein expressions of cyclooxygenase (COX)2, microsomal prostaglandin E synthase-1 derived eicosanoids (mPGES-1), 5-lipoxygenase (5-LOX), recombinant human mothers against decapentaplegic homolog 3 (Smad3), nucleotide-binding oligomerization domain-like receptor protein 3 (NALP3), and inducible nitric oxide synthase (iNOS) in rats' ankle synovial tissues (P<0.01). TSDN decreased COX1 mRNA and protein expression on 3rd and 5th day of drug administration and raised it on the 8th day (both P<0.01). It lowered CD68 protein expression on days 3 (P<0.01), as well as mRNA and protein expression on days 5 and 8 (P<0.01). On the 3rd, 5th, and 8th days of drug administration, TSDN elevated the mRNA and protein expression of Arg1 and CD163 (P<0.01). Flow cytometry results showed that TSDN decreased the percentage of M1 macrophages while increasing the percentage of M2 in peripheral blood (P<0.05 or P<0.01). ELISA results showed that on the 3rd, 5th, and 8th days of drug administration, TSDN decreased serum levels of IL-1 β, TNF-α, and LTB4 (P<0.01), as well as PGE₂ levels on days 3rd and 8th days (P<0.05 or P<0.01); on day 8 of administration, TSDN increased IL-4 serum levels and enhanced IL-10 contents on days 5 and 8 (P<0.05 or P<0.01). CONCLUSION The anti-inflammatory effect of TSDN on rats with GA may be achieved by influencing M1/M2 polarization through AA signaling pathway.
Rats ; Humans ; Animals ; Arthritis, Gouty/drug therapy* ; Monocytes/pathology* ; Interleukin-10/metabolism* ; Arachidonic Acid/pharmacology* ; Dioscorea/chemistry* ; Rats, Wistar ; Tumor Necrosis Factor-alpha/metabolism* ; Saponins/therapeutic use* ; Interleukin-4/metabolism* ; Leukotriene B4/pharmacology* ; Rats, Sprague-Dawley ; Macrophages ; Signal Transduction ; RNA, Messenger/metabolism*

Objective: To investigate the role and mechanism of tumor-derived mesenchymal stem cells in regulating the M2 polarization of macrophages within gastric cancer microenvironment. Methods: Gastric cancer tissues and the adjacent non-cancerous tissues were collected from patients underwent gastric cancer resection in the First People's Hospital of Lianyungang during 2018. In our study, THP-1-differentiated macrophages were co-cultured with gastric cancer-derived mesenchymal stem cells (GC-MSCs). Then, the M2 subtype-related gene, the markers expressed on cell surface and the cytokine profile were analyzed by real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR), flow cytometry and Luminex liquid chip, respectively. The key cytokines mediating the inducing effect of GC-MSCs on macrophage polarization into the M2 subtype were detected and screened by Luminex liquid chip, which were further confirmed by the neutralizing antibody test. The expressions of macrophage proteins involved in M2 polarization-related signaling pathways under the different co-culture conditions of GC-MSCs were detected by western blot. Results: In Mac+ GC-MSC-culture medium (CM) group, the expression levels of Ym-1 and Fizz-1 (1.53±0.32 and 13.22±1.05, respectively), which are markers for M2 subtype, were both significantly higher than those of Mac group (1.00±0.05 and 1.21±0.38, respectively, P<0.05). The level of iNOS in Mac+ GC-MSC-CM group (0.60±0.41) was significantly lower than that of Mac group (1.06±0.38, P=0.023). In Mac+ GC-MSC-Transwell (TW) group, the expression levels of Ym-1 and Fizz-1 (1.47±0.09 and 13.16±2.77, respectively) were both significantly higher than those of Mac group (1.00±0.05 and 1.21±0.38, respectively, P<0.05). The level of iNOS in Mac+ GC-MSC-CM group (0.56±0.03) was significantly lower than that of Mac group (1.06±0.38, P=0.026). The ratios of CD163(+) /CD204(+) cells in Mac+ GC-MSC-CM and Mac+ GC-MSC-TW groups (3.80% and 4.40%, respectively) were both remarkably higher than that of Mac group (0.60%, P<0.05). The expression levels of IL-10, IL-6, MCP-1 and VEGF in Mac+ GC-MSC-CM group were (592.60±87.52), (1 346.80±64.70), (11 256.00±29.03) and (1 463.90±66.67) pg/ml, respectively, which were significantly higher than those of Mac group [(41.03±2.59), (17.35±1.79), (5 213.30±523.71) and (267.12±12.06) pg/ml, respectively, P<0.05]. The levels of TNF-α, IP-10, RANTES and MIP-1α were (95.57±9.34), (410.48±40.68), (6 967.30±1.29) and (1 538.70±283.04) pg/ml, which were significantly lower than those of Mac group [(138.01±24.31, (1 298.60±310.50), (14 631.00±4.21) and (6 633.20±1.47) pg/ml, respectively, P<0.05]. The levels of IL-6 and IL-8 in GC-MSCs [(11 185.02±2.82) and (12 718.03±370.17) pg/ml, respectively] were both strikingly higher than those of MSCs from adjacent non-cancerous gastric cancer tissues [(270.71±59.38) and (106.04±32.84) pg/ml, repectively, P<0.05]. The ratios of CD86(+) cells in Mac+ IL-6-blocked-GC-MSC-CM and Mac+ IL-8-blocked-GC-MSC-CM groups (28.80% and 31.40%, respectively) were both higher than that of Mac+ GC-MSC-CM group (24.70%). Compared to Mac+ GC-MSC-CM group (13.70%), the ratios of CD204(+) cells in Mac+ IL-6-blocked-GC-MSC-CM and Mac+ IL-8-blocked-GC-MSC-CM groups (9.90% and 8.70%, separately) were reduced. The expression levels of p-JAK2 and p-STAT3, which are proteins of macrophage M2 polarization-related signaling pathway, in Mac+ GC-MSC-CM group (0.86±0.01 and 1.08±0.01, respectively) were significantly higher than those of Mac group (0.50±0.01 and 0.82±0.01, respectively, P<0.05). The expression levels of p-JAK2 in Mac+ IL-6-blocked-GC-MSC-CM group (0.47±0.02) were significantly lower those that of Mac+ GC-MSC-CM group (0.86±0.01, P<0.05). The expression levels of p-JAK2 and p-STAT3 in Mac+ IL-8-blocked-GC-MSC-CM group (0.50±0.01 and 0.85±0.01, respectively) were both significantly lower than those of Mac+ GC-MSC-CM group (0.86±0.01 and 1.08±0.01, P<0.05). The expression levels of p-JAK2 and p-STAT3 in Mac+ IL-6/IL-8-blocked-GC-MSC-CM group (0.37±0.01 and 0.65±0.01, respectively) were both significantly lower than those of Mac+ GC-MSC-CM group (0.86±0.01 and 1.08±0.01, P<0.05). Conclusion: GC-MSCs promote the activation of JAK2/STAT3 signaling pathway in macrophages via high secretions of IL-6 and IL-8, which subsequently induce the macrophage polarization into a pro-tumor M2 subtype within gastric cancer microenvironment.
Humans ; Interleukin-6/genetics* ; Interleukin-8/pharmacology* ; Janus Kinase 2/metabolism* ; Macrophages/metabolism* ; Mesenchymal Stem Cells ; STAT3 Transcription Factor/metabolism* ; Signal Transduction ; Stomach Neoplasms/pathology* ; Tumor Microenvironment

Objective To explore the role and mechanism of microRNA-204(miR-204) carried by the exosomes of human umbilical cord-derived mesenchymal stem cells(hUC-MSC) in regulating the polarization of macrophages in a mouse model of myocardial ischemia-reperfusion(I/R) injury. Methods After the hUC-MSCs were isolated,cultured,and identified,their adipogenic and osteogenic differentiation capabilities were determined.The exosomes of hUC-MSCs were separated by ultracentrifugation,and the expression of CD81,CD63,tumor susceptibility gene 101(Tsg101),and calnexin in the exosomes was determined by Nanoparticle Tracking Analysis software,transmission electron microscopy,and Western blotting.Three groups(hUC-MSC,miR-204 mimic,and negative control) were designed for the determination of the expression of miR-204 in the cells and their exosomes by qRT-PCR.The C57BL/6J mice were randomly assigned into a sham operation group,an I/R group,a hUC-MSC exosomes group,a negative control group,and a miR-204 mimic group.Except the sham operation group,the I/R model was established by ligating the left anterior descending artery.The echocardiography system was employed to detect the heart function of mice.HE staining was employed to observe the pathological changes of mouse myocardium.ELISA was employed to determine the levels of interleukin-1β(IL-1β),tumor necrosis factor-α(TNF-α),arginase 1(Arg-1),and IL-10 in the myocardial tissue.After the macrophages of mouse myocardial tissue were isolated,flow cytometry was employed to determine the expression of CD11c and CD206,and ELISA to measure the levels of IL-1β,TNF-α,Arg-1,and IL-10 in the macrophages. Results hUC-MSCs had adipogenic and osteogenic differentiation capabilities,and the exosomes were successfully identified.Compared with the negative control group,the miR-204 mimic group showed up-regulated expression of miR-204 in hUC-MSCs and their exosomes(P<0.001,P<0.001).Compared with the sham operation group,the modeling of I/R increased the left ventricular end-diastolic diameter(LVEDD)(P<0.001),left ventricular end-systolic diameter(LVESD)(P<0.001),myocardial injury score(P<0.001),and the levels of IL-1β(P<0.001),TNF-α(P<0.001),and CD11c(P<0.001).Meanwhile,it lowered the left ventricular ejection fraction(LVEF)(P<0.001),left ventricular fractional shortening(LVFS)(P<0.001),Arg-1(P<0.001),IL-10(P<0.001),and CD206(P<0.001).Compared with those in the I/R group,the LVEDD(P<0.001),LVESD(P<0.001),myocardial injury score(P<0.001),and the levels of IL-1β(P<0.001),TNF-α(P=0.010),and CD11c(P<0.001) reduced,while LVEF(P<0.001),LVFS(P<0.001),and the levels of Arg-1(P<0.001),IL-10(P=0.028),and CD206(P=0.022) increased in the hUC-MSC exosomes group.Compared with those in the negative control group,the LVEDD(P<0.001),LVESD(P<0.001),myocardial injury score(P=0.001),and the levels of IL-1β(P=0.048),TNF-α(P<0.001),and CD11c(P=0.007) reduced,while the LVEF(P<0.001),LVFS(P<0.001),and the levels of Arg-1(P<0.001),IL-10(P=0.001),and CD206(P=0.001) increased in the miR-204 mimic group. Conclusion The hUC-MSC exosomes overexpressing miR-204 can inhibit the polarization of macrophages in the I/R mouse model to M1-type and promote the polarization to M2-type.
Animals ; Humans ; Mice ; Disease Models, Animal ; Exosomes/pathology* ; Interleukin-10/metabolism* ; Macrophages ; Mesenchymal Stem Cells ; Mice, Inbred C57BL ; MicroRNAs/genetics* ; Myocardial Reperfusion Injury ; Osteogenesis ; Stroke Volume ; Tumor Necrosis Factor-alpha/metabolism* ; Umbilical Cord/pathology* ; Ventricular Function, Left

Studies have shown that chronic inflammatory response plays a key role in intracranial aneurysms (IA) formation and progression, and macrophages regulate the formation and progression of IA through a variety of pathways. Bone marrow monocyte-derived macrophages and resident-tissue macrophages infiltrate the vessel wall, after infiltration macrophages are polarized into various polarization phenotypes dominated by M1-like and M2-like cells. Polarized phenotypes of macrophages can regulate the formation and progression of intracranial aneurysms by releasing cytokines and regulating the inflammatory response of other immune cells, as well as release different cytokines to regulate the process of extracellular matrix remodeling. Some important progresses have been made in the clinical detection and treatment in targeting macrophages. This review provides a summary on the pathogenesis of IA and potential drug targets to prevent the formation and rupture of intracranial aneurysms.
Cytokines ; Disease Progression ; Humans ; Inflammation ; Intracranial Aneurysm ; complications ; drug therapy ; pathology ; Macrophages ; metabolism