OBJECTIVE: To summarize the research progress on the role of macrophage-mediated osteoimmune in osteonecrosis of the femoral head (ONFH) and its mechanisms. METHODS: Recent studies on the role and mechanism of macrophage-mediated osteoimmune in ONFH at home and abroad were extensively reviewed. The classification and function of macrophages were summarized, the osteoimmune regulation of macrophages on chronic inflammation in ONFH was summarized, and the pathophysiological mechanism of osteonecrosis was expounded from the perspective of osteoimmune, which provided new ideas for the treatment of ONFH. RESULTS: Macrophages are important immune cells involved in inflammatory response, which can differentiate into classically activated type (M1) and alternatively activated type (M2), and play specific functions to participate in and regulate the physiological and pathological processes of the body. Studies have shown that bone immune imbalance mediated by macrophages can cause local chronic inflammation and lead to the occurrence and development of ONFH. Therefore, regulating macrophage polarization is a potential ONFH treatment strategy. In chronic inflammatory microenvironment, inhibiting macrophage polarization to M1 can promote local inflammatory dissipation and effectively delay the progression of ONFH; regulating macrophage polarization to M2 can build a local osteoimmune microenvironment conducive to bone repair, which is helpful to necrotic tissue regeneration and repair to a certain extent. CONCLUSION At present, it has been confirmed that macrophage-mediated chronic inflammatory immune microenvironment is an important mechanism for the occurrence and development of ONFH. It is necessary to study the subtypes of immune cells in ONFH, the interaction between immune cells and macrophages, and the interaction between various immune cells and macrophages, which is beneficial to the development of potential therapeutic methods for ONFH.
Humans ; Femur Head/pathology* ; Osteonecrosis/therapy* ; Macrophages/pathology* ; Inflammation ; Femur Head Necrosis/pathology*

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*

Humans ; Tumor-Associated Macrophages/pathology* ; Neuroblastoma/pathology*

Bone marrow microenvironment is a highly complex environment surrounding tumor, which plays an important role in the survival, proliferation, drug resistance and migration of multiple myeloma (MM) cells. As an important cellular component in tumor microenvironment, tumor-associated macrophages(TAM) has attracted attention due to its key role in tumor progression and drug resistance. Targeting TAM has shown potential therapeutic value in cancer treatment. In order to clarify the role of macrophages in MM progression, it is necessary to understand the differentiation of TAM and its characteristics of promoting MM. This paper reviews the research progress on how TAM is programmed in MM and the mechanism of TAM promoting tumor development and drug resistance.
Humans ; Multiple Myeloma/pathology* ; Tumor-Associated Macrophages ; Macrophages/pathology* ; Cell Differentiation ; Tumor Microenvironment

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

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

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*

Idiopathic pulmonary fibrosis (IPF) is a progressive and fatal interstitial lung disease, the cause is not yet clear. Pathological manifestations are abnormal repair changes resulting from sustained lung injury. Macrophages have been identified as playing a key role in IPF pathogenesis. In different local microenvironments, macrophages can exhibit either classically activated (M1) or alternately activated (M2) phenotypes. M1 plays a key role in promoting inflammatory response and is involved in the process of causing alveolar tissue injury. M2 is involved in wound healing and stopping lung inflammation. Previous studies have shown that activation of 5-hydroxytryptamine (5-HT) signaling is enhanced in pulmonary fibrosis and that 5-HT receptors play an important role in the observed pro-fibrotic effects. As a multifunctional signaling molecule, 5-HT is closely related to lung macrophage polarization, early lung tissue injury, abnormal proliferation and repair, and late extracellular matrix (ECM) deposition. This article reviewed the role of 5-HT and M2 macrophages in the pathogenesis of IPF and the possible regulatory mechanism of 5-HT, in order to provide a reference for further research.
Humans ; Serotonin ; Macrophages ; Lung Diseases, Interstitial/pathology* ; Lung/pathology* ; Idiopathic Pulmonary Fibrosis ; Fibrosis