Decidual natural killer (dNK) cells are the most abundant immune cells at the maternal-fetal interface during early pregnancy in both mice and humans, and emerging single-cell transcriptomic studies have uncovered various human dNK subsets that are disrupted in patients experiencing recurrent early pregnancy loss (RPL) at early gestational stage, suggesting a connection between abnormal proportions or characteristics of dNK subsets and RPL pathogenesis. However, the functional mechanisms underlying this association remain unclear. Here, we established a mouse model by adoptively transferring human dNK cells into pregnant NOG (NOD/Shi-scid/IL-2Rγnull) mice, where human dNK cells predominantly homed into the uteri of recipients. Using this model, we observed a strong correlation between the properties of human dNK cells and pregnancy outcome. The transfer of dNK cells from RPL patients (dNK-RPL) remarkably worsened early pregnancy loss and impaired placental trophoblast cell differentiation in the recipients. These adverse effects were effectively reversed by transferring CD56+CD39+ dNK cells. Mechanistic studies revealed that CD56+CD39+ dNK subset facilitates early differentiation of mouse trophoblast stem cells (mTSCs) towards both invasive and syncytial pathways through secreting macrophage colony-stimulating factor (M-CSF). Administration of recombinant M-CSF to NOG mice transferred with dNK-RPL efficiently rescued the exacerbated pregnancy outcomes and fetal/placental development. Collectively, this study established a novel humanized mouse model featuring functional human dNK cells homing into the uteri of recipients and uncovered the pivotal role of M-CSF in fetal-supporting function of CD56+CD39+ dNK cells during early pregnancy, highlighting that M-CSF may be a previously unappreciated therapeutic target for intervening RPL.

Adult bones are continuously remodeled by the balance between bone resorption by osteoclasts and subsequent bone formation by osteoblasts. Many studies have provided molecular evidence that bone remodeling is under the control of circadian rhythms. Circadian fluctuations have been reported in the serum and urine levels of bone turnover markers, such as digested collagen fragments and bone alkaline phosphatase. Additionally, the expressions of over a quarter of all transcripts in bones show circadian rhythmicity, including the genes encoding master transcription factors for osteoblastogenesis and osteoclastogenesis, osteogenic cytokines, and signaling pathway proteins. Serum levels of calcium, phosphate, parathyroid hormone, and calcitonin also display circadian rhythmicity. Finally, osteoblast- and osteoclast-specific knockout mice targeting the core circadian regulator gene Bmal1 show disrupted bone remodeling, although the results have not always been consistent. Despite these studies, however, establishing a direct link between circadian rhythms and bone remodeling in vivo remains a major challenge. It is nearly impossible to repeatedly collect bone materials from human subjects while following circadian changes. In addition, the differences in circadian gene regulation between diurnal humans and nocturnal mice, the main model organism, remain unclear. Filling the knowledge gap in the circadian regulation of bone remodeling could reveal novel regulatory mechanisms underlying many bone disorders including osteoporosis, genetic diseases, and fracture healing. This is also an important question for the basic understanding of how cell differentiation progresses under the influence of cyclically fluctuating environments.

The release of danger signals from tissues in response to trauma during cardiac surgery creates conditions to reprogram the immune system to subsequent challenges posed by pathogens in the postoperative period. To demonstrate this, we tested immunoreactivity before surgery as the baseline (tbaseline), followed by subsequent challenges during the acute phase (t24h), convalescence (t7d), and long-term recovery (t3m). For 108 patients undergoing elective heart surgery, whole blood was stimulated with lipopolysaccharide (LPS), Influenza A virus subtype N2 (H3N2), or the Flublok™ vaccine to represent common pathogenic challenges. Leukocytosis, platelet count, and serum C-reactive protein (CRP) were used to measure non-specific inflammation. Cytokines were measured after 18 h of stimulation to reflect activation of the various cell types (activated neutrophils-IL-8; activated T cells-IL-2, IFNγ, activated monocyte (MO)-TNFα, IL-6, and deactivated or atypically activated MO and/or T cells-M-CSF, IL-10). IL-2 and IL-10 were increased at t7d, while TNFα was suppressed at t24h when LPS was utilized. Interestingly, M-CSF and IL-6 production was elevated at seven days in response to all stimuli compared to baseline. While some non-specific markers of inflammation (white cell count, IL-6, and IL-8) returned to presurgical levels at t3m, CRP and platelet counts remained elevated. We showed that surgical stimulus reprograms leukocyte response to LPS with only partial restoration of non-specific markers of inflammation.

BACKGROUND: Lung adenocarcinoma (LUAD) is the most prevalent subtype of lung cancer. Xklp2 targeting protein (TPX2), a crucial oncogene exhibits high expression levels in various cancers including LUAD, may serve as a potential target for clinical intervention. Additionally, the growth of lung cancer is significantly influenced by the tumor microenvironment (TME). However, there have been no reports on experiments investigating TPX2 in tumor-infiltrating immune cells (TIICs) in LUAD. Therefore, we verified the effect of TPX2 on macrophage polarization both in vitro and in vivo.
METHODS: We silenced TPX2 the gene in A549 cells and collected supernatants for macrophage culture. We then used flow cytometry and Western blot analysis to assess macrophage polarization. Additionally, we verified the expression of macrophage colony-stimulating factor (M-CSF), and CD163 by immunohistochemistry (IHC) in tissue specimens from LUAD patients. Finally, pathways related to TPX2\'s regulatory function in macrophage polarization were analyzed through whole genome sequencing, Western blotting, and immunofluorescence (IF).
RESULTS: Silencing TPX2 can affect the ratio of CD80+ M1/CD163+ M2 and reduce the polarization of M0 macrophages to CD163+ M2 macrophages mainly by inhibiting the expression of M-CSF. In human LUAD tissues, the expression levels of TPX2, M-CSF and CD163 increased with the degree of differentiation. Silencing TPX2 inhibits the NF-κB signaling pathway, thereby reducing the expression of M-CSF, and affecting macrophage polarization.
CONCLUSIONS: Silencing TPX2 can inhibit the expression of M-CSF by blocking the NF-κB signal, thereby reducing CD163+ M2 macrophage polarization. The TPX2/NF-κB/M-CSF signaling axis may be involved in regulating macrophage polarization.

Psoriasis is a chronic, complex, and immunologically mediated systemic disease that not only affects the skin, but also the joints and nails. It may coexist with various other disorders, such as depression, psoriatic arthritis, cardiovascular diseases, diabetes mellitus, and metabolic syndrome. In particular, the potential link between psoriasis and metabolic syndrome is an issue worthy of attention. The dysregulation of growth factors could potentially contribute to the disturbances of keratinocyte proliferation, inflammation, and itch severity. However, the pathophysiology of psoriasis and its comorbidities, such as metabolic syndrome, remains incompletely elucidated. Growth factors and their abnormal metabolism may be a potential link connecting these conditions. Overall, the objective of this review is to analyze the role of growth factor disturbances in both psoriasis and metabolic syndrome.

To investigate the effect of Src homology 2 domain-containing tyrosine phosphatase-2 (SHP2) in tumor-associated macrophages (TAMs), which is mediated by macrophage colony-stimulating factor (M-CSF) secreted by gastric cancer cells, on the development of gastric cancer and its molecular mechanism.
The progression of gastric cancer was detected by nude mouse tumor-bearing experiments. Colony formation assay and cell counting kit-8 (CCK8) assay were used to detect the proliferation capacity of gastric cancer cells. The migration capacity of gastric cancer cells was examined by wound healing assay. Transwell migration and invasion assays were performed on gastric cancer cells. Detection of relevant protein expression using western blotting.
Overexpression of SHP2 could promote the progression of gastric cancer in nude mice. The results of colony formation assay and CCK8 assay showed that overexpression of SHP2 could enhance the proliferation of gastric cancer cells. It was found by wound healing assay and Transwell assay that overexpression of SHP2 could facilitate the migration and invasion of gastric cancer cells. The results of Western blotting revealed that overexpression of SHP2 could increase the expressions of p-STAT3, s-PD-1, p-Src, p-Lyn, p-PI3K, p-AKT, Arginase-1, MMP1 and MMP3 but decrease the expressions of TBK1 and SOCS1 in TAMs, and also increase the expressions of CD9, TSG101 and s-PD-1 in exosomes.
M-CSF secreted by gastric cancer cells can promote the proliferation, invasion and migration of gastric cancer cells by increasing the expression of SHP2 in TAMs.

BACKGROUND: Macrophages (Mφ) can exist along a spectrum of phenotypes that include pro-inflammatory (M1) or anti-inflammatory (M2) immune cells. Mφ colony stimulating factor (M-CSF) and granulocyte Mφ colony stimulating factor (GM-CSF) are cytokines important in hematopoiesis, polarization and activation of Mφ.
RESULTS: To gain a greater understanding of the relationship between GM-CSF and M-CSF, we investigated an in vitro model of differentiation to determine if GM-CSF and M-CSF can antagonize each other, in terms of Mφ phenotype and functions. We determined that Mφ cultured in mixed M-CSF: GM-CSF ratios exhibit M1-like GM-CSF-treated macrophage phenotype when the ratios of the two cytokines are 1:1 in culture. Moreover, GM-CSF is dominant over M-CSF in influencing Mφ production of proinflammatory cytokines such as IL-6, TNFα, and IL-12p40, and the anti-inflammatory cytokine IL-10.
CONCLUSIONS: Our data established that GM-CSF is more dominant over M-CSF, triggering the Mφ to become pro-inflammatory cells. These findings provide insight into how GM-CSF can influence Mφ activation with implications in inflammatory diseases where the Mφ status can play a significant role in supporting the inflammatory conditions.

Immunometabolism has been unveiled in the last decade to play a major role in controlling macrophage metabolism and inflammation. There has been a constant effort to understand the immunomodulating properties of regulated metabolites during inflammation with the aim of controlling and re-wiring aberrant macrophages in inflammatory diseases. M-CSF and GM-CSF-differentiated macrophages play a key role in mounting successful innate immune responses. When a resolution phase is not achieved however, GM-CSF macrophages contribute substantially more towards an adverse inflammatory milieu than M-CSF macrophages, consequently driving disease progression. Whether there are specific immunometabolites that determine the homoeostatic or inflammatory nature of M-CSF and GM-CSF-differentiated macrophages is still unknown. As such, we performed metabolomics analysis on LPS and IL-4-stimulated M-CSF and GM-CSF-differentiated human macrophages to identify differentially accumulating metabolites. Adenine was distinguished as a metabolite significantly higher in M-CSF-differentiated macrophages after both LPS or IL-4 stimulation. Human macrophages treated with adenine before LPS stimulation showed a reduction in inflammatory gene expression, cytokine secretion and surface marker expression. Adenine caused macrophages to become more quiescent by lowering glycolysis and OXPHOS which resulted in reduced ATP production. Moreover, typical metabolite changes seen during LPS-induced macrophage metabolic reprogramming were absent in the presence of adenine. Phosphorylation of metabolic signalling proteins AMPK, p38 MAPK and AKT were not responsible for the suppressed metabolic activity of adenine-treated macrophages. Altogether, in this study we highlight the immunomodulating capacity of adenine in human macrophages and its function in driving cellular quiescence.

Testicular macrophages (TM) are critical for the function of the testis by regulating homeostasis and inflammatory responses. However, the mechanisms by which TM fulfil these roles remain elusive. In this study, we explored the impact of two key testicular microenvironmental factors, namely 25-hydroxycholesterol (25HC), an oxysterol related to sex hormones and macrophage colony-stimulating factor (M-CSF), a factor crucial for macrophage survival and differentiation, on the regulation of the TM phenotype. Specifically, we examined their role in controlling the expression of the transcription factor interferon regulatory factor 7 (Irf7), a factor critical for maintaining the alternative macrophage phenotype. To achieve this, we used an in vitro bone marrow-derived macrophage (BMDM) model as a surrogate for TM to investigate the roles of 25HC and M-CSF in regulating the expression of Irf7 during the polarization of murine TM. M-CSF was identified as the main regulator of Irf7 expression, while 25HC production is a consequence of Irf7 activation in BMDM. In turn, 25HC plays a role in a negative feedback loop on the expression levels of Irf7 in BMDM. Using flow cytometry in Irf7-/- mouse testis the CD64loMHChi TM subpopulation was found to be decreased. Together with lower IL-10 protein levels in Irf7-/- TM this indicates a shift towards an M1-like macrophage profile. In summary, our data indicates that M-CSF could act as an inducer of high Irf7 expression levels in the mouse testis. However, the exact role of the high 25HC concentration in the testis in maintaining the local immune milieu still needs further study.

WNT4 gene polymorphism are common in endometriosis and may functionally link estrogen and estrogen receptor signaling. Previous study confirmed estrogen and estrogen receptor signaling recruit macrophage to promote the pathogenesis of endometriosis. To investigate the effect of WNT4 in endometriosis involved in macrophage polarization and whether WNT4 could reduce the apoptosis of granulosa cells.
An observational study consisting of 8 cases of women with endometriosis (diagnosed by surgery and histology) and 22 mice of endometriosis animal model was conducted. Granulosa cells were isolated from 16 patients with endometriosis and co-cultured with macrophage under WNT4 treatment using TUNEL assay, quantitative reverse transcription PCR, flow cytometry and ELISA analysis. 22 mice of endometriosis animal model confirmed the WNT4 treatment effects using histology and immunohistochemistry, Western blot and flow cytometry.
We observed that the apoptotic proportion of granulosa cells was significantly decreased and M2 macrophage was significantly increased after WNT4 treatment during the granulosa cell and macrophage co-culture system. To reveal the underlying mechanism for this, we conducted a series of experiments and found that high expression of granulosa cell M-CSF led to the M2 polarization of macrophages. The animal model also suggested that the anti-apoptotic effect of WNT4 on granulosa cells were conducted by the M2 polarized macrophage.
WNT4 could reduce granulosa cell apoptosis and improve ovarian reserve by promoting macrophage polarization in endometriosis. M-CSF secreted by granulosa cell after WNT4 treatment was the main mediator of macrophage polarization.