Concentrations Of Macrophage Colony-stimulating Factor Research Articles

A quantitative analysis of macrophage-colony-stimulating factor in peri-miniscrew implant crevicular fluid before and after orthodontic loading.

To analyze macrophage-colony-stimulating factor (M-CSF), a bone remodeling biomarker in the peri-miniscrew implant crevicular fluid (PMICF) after insertion and orthodontic loading. This prospective study included 40 miniscrew implant (MSI) sites in 10 subjects undergoing fixed orthodontic mechanotherapy utilizing miniscrew anchorage. After dental alignment, miniscrews were inserted between the second premolar and first molar roots. After 21 days of insertion, MSIs were direct loaded with closed-coil springs (200 g force) for en masse retraction of anterior teeth. PMICF was collected with Periopaper™ strips from the gingival crevice around MSIs at six time points (T1-T6: 1 hour, 1 day, 21 days postinsertion, and 7, 21, and 42 days postloading). PMICF was quantified for M-CSF by enzyme-linked immunosorbent assay. Paired comparison of mean M-CSF concentrations before and after loading stages (T1-T6) was made using the Wilcoxon signed-rank test. The mean M-CSF concentration showed a significant peak at T3 (21 days postinsertion; 12.646 pg/mL; T1 vs T3: P < .0001). After orthodontic loading of miniscrews, M-CSF levels increased to 13.570 pg/mL at T4 (7 days after loading; T1 vs T4: P < .001) and maintained at a plateau to T5 (21 days postloading; 11.994 pg/mL). However, the difference between preloading and postloading was not statistically significant (T3 vs T4). The maximum M-CSF activity around MSIs was observed at around 3 weeks of miniscrew insertion, suggesting underlying bone remodeling after surgical injury. However, orthodontic force on MSIs did not cause any significant surge in M-CSF levels postloading.

Evaluation of the oxytocin effect in a rat model with experimental periodontitis.

The aim of the present study was to evaluate the inhibitory effects of oxytocin on the development of periodontitis based on its properties against bone loss and resorption. Thirty-two Wistar albino rats were divided into four equal groups: control, periodontitis + saline, periodontitis + 0.5mg/kg/day oxytocin, and periodontitis + 1mg/kg/day oxytocin. Periodontitis groups received 4.0 silk ligatures around their cervixes of the right and left mandibular incisors in an "8" shape, kept for 14days. Animals in oxytocin groups were injected once every day during 14days with oxytocin. The mandibles were fixed and scanned using microcomputed tomography to quantify bone resorption and volumetric measurements. Blood samples were collected to analyze the concentrations of macrophage colony-stimulating factor (M-CSF), receptor activator of nuclear factor-κΒ ligand (RANKL), osteoprotegerin (OPG), matrix metalloproteinase-8 (MMP-8), tumor necrosis factor-alpha (TNF-α), interleukin (IL)-6, glutathione peroxidase (GPx), superoxide dismutase (SOD), and malondialdehyde (MDA). Histopathological evaluations were conducted to examine the gingiva and alveolar bone. Oxytocin prevented the development of periodontitis by decreasing ligament deteriorations and leukocytes in the gingival connective tissue and promoting reintegration with the alveolar bone. Bone resorption in all regions was less in the periodontitis + 1mg/kg/day oxytocin group than in the periodontitis + saline group. Although TNF-α, IL-6, and RANKL values were lower in the periodontitis + 1mg/kg/day oxytocin group, OPG was higher than that in the periodontitis + saline group. M-CSF, MMP-8, and MDA were lower in the oxytocin groups than in the periodontitis + saline group. Oxytocin may be an effective agent for periodontal diseases because it decreased bone resorption, oxidative stress, and inflammation in an experimental periodontitis.

Abstract 1605: "Reverse abscopal effect": Immunologically cold tumors alter systemic immunity and confer PD-1 resistance to immunologically hot tumors in synchronous melanoma

Abstract PD-1 (programmed cell death protein-1) blockade, an immunotherapy that re-stimulates antitumor CD8 T cell response, has revolutionized the treatment of metastatic melanoma. However, the majority of melanoma patients eventually acquire therapy resistance. The emergence of resistant metastases likely results from de novo somatic mutations secondary to inherent tumor genetic instability. We hypothesize that intertumoral genetic differences introduce immunosuppressive mechanisms, such as inducing myeloid-derived suppressor cell differentiation, that dampen existing antitumor immune responses. As all metastases share one host immune system, we investigated the local and systemic effects of intertumoral heterogeneity on antitumor immunity and PD-1 immunotherapy response in mice with multiple, synchronous melanoma metastases. To recapitulate intertumoral heterogeneity, we simultaneously injected PD-1 blockade-resistant YUMM 1.7 and its UVB-irradiated, PD-1 sensitive, derivative YUMMER 1.7 melanoma cell lines into opposite flanks of the same C57BL/6J mouse. We previously demonstrated that tumor-specific de novo somatic mutations, in combination with the host immune response, generate distinct microenvironments in synchronous YUMMER (immunologically active) and YUMM (immunologically inactive) tumors. Our novel murine synchronous melanoma model demonstrated that the presence of immunologically inactive YUMM tumors changes systemic antitumor immunity, including the induction of host splenic myelopoiesis. This phenomenon is accompanied by an increase in YUMMER intratumoral M-CSF (macrophage colony stimulating factor) concentration and an influx of immunosuppressive PD-L1+ (PD-1 ligand) macrophages into YUMMER tumors as assessed by flow cytometry and Luminex analyses. Furthermore, compared to control CD8 T cells, synchronous YUMMER-infiltrating CD8 T cells exhibit reduced functionality, with increased surface PD-1 persistence and failure to respond to PD-1 blockade. As a result, the presence of YUMM tumors are able to confer PD-1 blockade resistance to the normally PD-1 sensitive YUMMER tumors. Our results suggest that intertumoral heterogeneity leads to a “reverse abscopal effect,” where immunologically “cold” tumors can alter systemic myeloid immune responses to suppress antitumor CD8 T cell function in immunologically “hot” tumors. As such, the addition of myeloid-altering agents to PD-1 immunotherapy are likely to improve treatment efficacy and prevent acquired therapy resistance in patients with metastatic melanoma. Citation Format: Shuyang S. Qin, Booyeon J. Han, Alexander C. Chacon, Alexa D. Melucci, Alyssa R. Williams, Rachel Jewell, Minsoo Kim, David C. Linehan, Scott A. Gerber, Peter A. Prieto. "Reverse abscopal effect": Immunologically cold tumors alter systemic immunity and confer PD-1 resistance to immunologically hot tumors in synchronous melanoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1605.

Tumor-Released Products Promote Bone Marrow-Derived Macrophage Survival and Proliferation

Macrophages play a central role within the tumor microenvironment, with relevant implications for tumor progression. The modulation of their phenotype is one of the mechanisms used by tumors to escape from effective immune responses. This study was designed to analyze the influence of soluble products released by tumors, here represented by the tumor-conditioned media of two tumor cell lines (3LL from Lewis lung carcinoma and MN/MCA from fibrosarcoma), on murine macrophage differentiation and polarization in vitro. Data revealed that tumor-conditioned media stimulated macrophage differentiation but influenced the expression levels of macrophage polarization markers, cytokine production, and microRNAs of relevance for macrophage biology. Interestingly, tumor-derived soluble products supported the survival and proliferation rate of bone marrow precursor cells, an effect observed even with mature macrophages in the presence of M2 but not M1 inducers. Despite presenting low concentrations of macrophage colony-stimulating factor (M-CSF), tumor-conditioned media alone also supported the proliferation of cells to a similar extent as exogenous M-CSF. This effect was only evident in cells positive for the expression of the M-CSF receptor (CD115) and occurred preferentially within the CD16+ subset. Blocking CD115 partially reversed the effect on proliferation. These results suggest that tumors release soluble products that not only promote macrophage development from bone marrow precursors but also stimulate the proliferation of cells with specific phenotypes that could support protumoral functions.

The inhibitory effect of melatonin on osteoclastogenesis of RAW 264.7 cells in low concentrations of RANKL and MCSF.

RAW 264.7 cells are one of the most recommended cell lines for investigating the activity and differentiation of osteoclasts. These cells differentiate into osteoclasts in the presence of two critical components: receptor activator of nuclear factor kappa B ligand (RANKL) and macrophage colony stimulating factor (MCSF). Melatonin (MEL) hormone has recently become one of the small molecules used in the field of bone regeneration and bone disease treatment, as it has the ability to inhibit the differentiation of osteoclasts directly by suppression of the NF-κB signaling pathway. The main aim of the current study is to determine sufficient RANKL/MCSF concentrations for differentiation of the cells to osteoclasts and to describe the repressive effect of MEL on the osteoclastogenesis of these cells. In this regard, it was found that 10 ng/mL of RANKL- and MCSF-containing medium is suitable for inducing osteoclastogenesis of the cells. In addition, melatonin at doses in the range of 100–1000 µM does not have a cytotoxic effect. Subsequently, results of tartrate resistant acid phosphatase (TRAP) activity, TRAP staining, and relative expressions of cathepsin K, nuclear factor of activated T cells one (NFATC1), and TRAP genes showed a suppressive effect of MEL —especially 800 µM— on RANKL-induced osteoclastogenesis of these cells.

Monocyte chemoattractant protein-1, macrophage colony stimulating factor, survivin, and tissue inhibitor of matrix metalloproteinases-2 in analysis of damage and repair related to pediatric chronic kidney injury.

Kidney injury in the course of chronic kidney disease (CKD) is a consequence of aggravated cell migration, inflammation, apoptosis, and fibrosis. However, the sequence of these phenomena, as well as of the reparatory mechanisms, are not fully known. Monocyte chemoattractant protein 1 (MCP-1) and macrophage colony-stimulating factor (MCSF) trigger monocyte migration to the sites of inflammation and their transition into macrophages. Tissue inhibitor of matrix metalloproteinases-2 (TIMP-2) plays a protective role against excessive matrix remodeling, whereas survivin is known for its anti-apoptotic activity. To analyze the serum, urine and fractional excretion (FE) values of MCP1, MCSF, TIMP-2, and survivin in children at subsequent stages of CKD being treated conservatively, and to analyze the potential applicability of these markers in the evaluation of CKD-related renal damage and protective mechanisms against it. The study group consisted of 70 children with conservatively treated CKD, stages 1-5, and 12 controls. The serum and urine concentrations of MCP1, MCSF, TIMP-2, and survivin were assessed using enzyme-linked immunosorbent assay (ELISA). The FE of these parameters in the urine was also assessed. The serum values of all parameters were significantly elevated at CKD stage 1 compared to the controls. The urinary concentrations of MCP-1 and MCSF (stages 1-2) rose earlier than TIMP-2 and survivin (stage 4) concentrations. The FE values started increasing at CKD stage 3 (MCP-1) or stage 4 (other parameters). The complex analysis of serum/urinary/FE values of the selected parameters revealed a sequence of multifaceted CKD-related phenomena, when the migration of cells and inflammation were followed by delayed and insufficient anti-fibrotic and anti-apoptotic activity.

Association of plasma macrophage colony-stimulating factor with cardiovascular morbidity and all-cause mortality in chronic hemodialysis patients

BackgroundCardiovascular disease (CVD) events are the main cause of death in long-term hemodialysis (HD) patients. Macrophage colony- stimulating factor (M-CSF) is actively involved in the formation of atherosclerosis and causes plaque instability, thrombosis and the development of acute coronary syndromes. However, little information is available on the role of M-CSF in HD patients. We aimed to investigate the association between plasma M-CSF levels and CVD events as well as all-cause mortality in patients undergoing long-term HD.MethodsFifty two HD patients and 8 healthy controls were recruited in this study. HD patients were followed up from September 2014 to May 2017. The primary end point was CVD event, the secondary outcome was death from any cause. Patients were divided into two groups with low and high M-CSF levels based on the optimal cut-off value determined by the ROC curve. Cox regression analyses were used to assess the predictive value of plasma M-CSF for CVD events and all-cause mortality in HD patients. We tested the levels of plasma M-CSF and other inflammatory cytokines in surviving HD patients using ELISA or CBA kit.ResultsThe average plasma level of M-CSF in 52 patients was approximately twice that of healthy controls (992.4 vs. 427.2 pg/mL; p < 0.05). During 32 months of follow-up, 26 patients (50.0%) had at least one CVD event and 8 patients (15.4%) died. The mean plasma M-CSF concentration increased in survivors after follow-up compared to that detected at baseline (1277.8 ± 693.3 vs. 997.2 ± 417.4 pg/mL; p < 0.05). Multivariate Cox regression analysis showed that plasma M-CSF is an independent risk factor for CVD events in HD patients (p < 0.05). In the Cox regression model after adjusting for gender and age, high M-CSF levels were related to an increased risk of all-cause death (p < 0.05). We also found that M-CSF levels were positively correlated with IL-6 and IL-18 levels (both p < 0.05), which are the major pathogentic cytokines that contribute to HD-related CVD events.ConclusionM-CSF is a prognostic factor for CVD events and all-cause mortality in HD patients.

Immunological markers of alimentary-induced hyperlipidemia in Wistar rats

Changes in plasma levels of the main groups of cytokines and adipokines may correlate with the severity of metabolic disorders in hyperlipidemia and obesity. The aim of the study was to assess the significance of ghrelin, leptin, their ratio (L/Gh), and the cytokine profile as biomarkers at dietary-induced hyperlipidemia. Material and methods. We used 48 female Wistar rats with an initial body weight of 123±1 g, which were divided into 6 groups. Group 1 (control) received a balanced semi-synthetic diet according to AIN93; group 2 - diet with excess fat (30% by weight); group 3 - a diet with the addition of 20% fructose solution instead of drinking water, group 4 - a diet with excess fat and fructose, group 5 - a diet with added cholesterol (0.5%), group 6 - a diet with cholesterol and fructose. On the 64th day of the experiment, the mass of internal organs was determined; the levels of cytokines and adipokines in blood plasma were measured by multiplex immunoassay. Results and discussion. A decrease in the level of leptin was found in group 5 compared with the control and with groups 2, 4 and 6 groups (p<0.05). The lowest level of ghrelin was found in group 2 (p<0.05) against the background of high concentrations of leptin. Significant correlations were found between L/Gh and the total mass of animals (r=0.321; р=0.034), the relative mass of adipose tissue (r=0.439; р=0.003) and with the relative mass of the spleen (r=-0.460; р=0.003). In group 2, at the maximum L/Gh ratio, a significantly higher weight of adipose tissue was found, whereas in groups 3 and 5, at the lowest L/Gh ratio, the relative amount of total fat was the lowest. L/Gh ratio correlated with the level of monocyte chemotactic protein-1 (MCP-1), RANTES, IL-18 and macrophage colony-stimulating factor (M-CSF). The concentrations of IL-17, IL-18, IL-4, IL-5, MIP-3a, IFN-γ, M-CSF and RANTES in the experimental groups were reduced compared with the control, with the most pronounced effect in group 5 together with the lowest L/Gh ratio. Conclusion. The presence of a significant correlation between L/Gh ratio and changes in the weight of rats' body, spleen, adipose tissue, as well as levels of cytokines involved in inflammation regulation, confirms the importance of L/Gh ratio as a biomarker in an in vivo model of dyslipidemia.

New markers of cell migration and inflammation in children with chronic kidney disease

Context: Chronic kidney disease (CKD) is characterized by immunocompetent cell migration and inflammation. Monocyte chemoattractant protein (MCP)-1 and macrophage colony-stimulating factor (MCSF) stimulate monocyte migration and transition into macrophages with subsequent release of neopterin. Objective: The aim of the study was to analyze these parameters in children with various stages of CKD. Material and methods: The study group consisted of 41 CKD children, 19 patients on haemodialysis (HD), 22 children on automated peritoneal dialysis (APD) and 23 controls. Serum concentrations of MCP-1, MCSF and neopterin were assessed by ELISA. Correlations to matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) were analyzed. Results: MCP-1, MCSF and neopterin were significantly elevated in all patients versus controls and the highest values concerned HD children. A single HD session lessened the concentrations of all parameters, yet they rose back before the next HD session. All markers correlated with MMPs and TIMPs in different combinations. Conclusions: Systemic inflammation and cell migration are triggered by CKD and additionally aggravated by chronic dialysis, with the more evident negative impact of HD than APD. Discrepancies in MCP1, MCSF and neopterin serum concentrations suggest they may serve as new markers of cellular and inflammatory responses in children with CKD.

New Markers of Inflammation and Tubular Damage in Children with Chronic Kidney Disease.

Introduction and Aims Monocyte chemoattractant protein- (MCP-) 1, macrophage colony-stimulating factor (MCSF), and neopterin are connected with monocyte migration and transition into macrophages, leading to fibrosis and tubular damage in the course of CKD. The aim of the study was to analyze the applicability of urinary fractional excretion (FE) of MCP1, MCSF, and neopterin, as markers of inflammation and tubular damage, in children with CKD. Methods The study group consisted of 61 children with CKD stages 1–5 and 23 age-matched controls. The serum and urine concentrations of MCP1, MCSF, and neopterin were assessed by ELISA and then the fractional excretion (FE) was calculated. Results FE MCSF and neopterin values exceeded 1% already in controls. FE MCSF rose significantly since CKD stages 1-2, FE neopterin since CKD stages 3–5. FE MCP1 was below 1% in healthy controls and in CKD stages 1-2, then increased significantly in CKD stages 3–5. Conclusions The FE MCP-1 values show that inflammation precedes the tubular dysfunction. FE MCSF and FE neopterin may be considered new markers of the renal parenchyma progressive damage. Fractional excretion may become a useful tool in the assessment of inflammation and tubular damage in children with CKD.

Early risk prognosis of free-flap transplant failure by quantitation of the macrophage colony-stimulating factor in patient plasma using 2-dimensional liquid-chromatography multiple reaction monitoring-mass spectrometry.

Although great success of microvascular free-flap transplantation surgery has been achieved in recent years, between 1.5% and 15% of flaps are still lost due to vascular occlusion. The clinical challenge remains to salvage a transplant in the case of vascular complications. Since flap loss is devastating for the patient, it is of utmost importance to detect signs of complications or of conspicuities as soon as possible. Rescue success rates highly depend on early revision. In this study, we collected blood samples during transplantation surgery from either the contributory artery or the effluent vein of the flap and applied a targeted mass spectrometry-based approach to quantify 24 acute phase proteins, cytokines, and growth factors in 63 plasma samples from 21 hospitalized patients, generating a dataset with 9450 protein concentration values. Biostatistical analyses of the targeted plasma protein concentrations in all 63 plasma samples showed that venous concentrations of macrophage colony-stimulating factor (M-CSF) provided the highest accuracy for discriminating patients with either clinical conspicuities or complications from control individuals. Using 21.33 ng/mL of M-CSF as the diagnostic threshold when analyzing venous blood plasma samples, the assay obtained a sensitivity of 0.93 and a specificity of 0.85 with an area under the curve value of 0.902 in the receiver operating characteristic analysis. Overall, our results indicate that M-CSF is a potential molecular marker for early risk prognosis of free-flap transplant failure.

Increased serum concentrations of inflammatory cytokines in type 2 diabetic patients with chronic kidney disease

To study the relationship between serum inflammatory cytokine levels in chronic kidney disease patients with type 2 diabetes. Sixty-four patients aged 43 to 70 years with a glomerular filtration rate (GFR) of > 30 ml/min/1.73 m2 were examined. A control group consisted of 15 healthy individuals. The serum concentration of macrophage colony-stimulating factor (M-CSF), macrophage inflammatory protein 1α (MIP-1α), macrophage migration inhibitory factor (MIF), interleukin 6 (IL-6), as well as the urinary excretion of albumin and type IV collagen was determined by enzyme immunoassay. In patients with a GFR of > 60 ml/min/1.73 m2, M-CSF and MIF concentrations proved to be significantly higher than those in the control group (p = 0.0003 and p = 0.001, respectively). In those with a GFR of 30-59 ml/min/1.73 m2, there was an increase in the levels of M-CSF (p < 0.0001), MIP-1α (p = 0.002), MIF (p = 0.02), and IL-6 (p = 0.02). The decline in GFR was associated with the higher levels of M-CSF (p = 0.02) and MIP-1α (p = 0.02) and with the higher urinary excretion of type IV collagen (p = 0.01). M-CSF, MIP-1α, and IL-6 correlated positively with the urinary excretion of albumin (r = 0.34, r = 0.28, and r = 0.28, respectively; all p < 0.05) and type IV collagen (r = 0.31, r = 0.4, and r = 0.43, respectively; all p < 0.05). The findings confirm the concept that chronic inflammation is involved in the development of diabetic kidney disease.

Increased expression of M-CSF and IL-13 in vitreous of patients with proliferative diabetic retinopathy: implications for M2 macrophage-involving fibrovascular membrane formation

PurposeWe recently demonstrated that M2 macrophages were involved in the development of fibrovascular membranes (FVM) associated with proliferative diabetic retinopathy (PDR) possibly through the induction of periostin. The purpose of...

Peripheral Blood Mononuclear Phagocytes From Patients With Chronic Periodontitis Are Primed for Osteoclast Formation

During inflammatory periodontal disease, peripheral blood mononuclear cells (PBMCs) are attracted to bone and differentiate into active bone-resorbing osteoclasts (OCs), thus providing evidence that the impact of chronic periodontitis (CP) on the activity of circulating mononuclear cells is of central importance. The authors test the hypothesis that peripheral blood mononuclear phagocytes (PBMPs) from patients with CP are activated and more susceptible to differentiation into OCs, which in turn would lead to more intense bone resorption. In vitro cytokine production by both unstimulated and lipopolysaccharide-stimulated PBMCs from individuals with (n = 10) or without (n = 12) periodontitis was determined by cytokine array. OC differentiation from CD14(+) PBMCs was induced by receptor activator of nuclear factor-kappa B ligand (RANKL), either alone or in the presence of macrophage colony-stimulating factor (M-CSF). PBMC differentiation to OCs was confirmed by tartrate-resistant acid phosphatase staining; bone resorbing activity was assessed by using an osteologic plate assay (bone resorption pit formation). PBMCs from patients with CP produced tumor necrosis factor-α and higher amounts of interferon-γ, interleukin (IL)-1α, IL-1β, IL-1rα, CXC motif chemokine 10, macrophage migration inhibitory factor, macrophage inflammatory protein (MIP)-1α, and MIP-1β than the control cells. OC differentiation was induced by RANKL alone in PBMCs from patients with CP, but not in PBMCs from the healthy controls, which required the addition of M-CSF. In addition, PBMC-derived OCs from patients with CP showed significantly higher resorption activity than that observed in the healthy controls. Also, the circulating concentrations of M-CSF were significantly higher in patients with CP than in the control participants. These data indicate that in patients with CP, circulating PBMCs are primed for increased proinflammatory activity and that M-CSF plays a central role in this process by increasing OC formation and the consequent bone resorption activity.

EFFICACY OF IMMUNOCORRECTIVE TREATMENT WITH SYNTHETIC DIPEPTIDE IN CHILDREN WITH PYELONEPHRITIS

The results of the open controlled prospective clinical and immunological trial indicate that including of pidotimod into the complex therapy of pyelonephritis in children (n=30) lead to reliable decrease of recurrence risk and frequency during 6 months after treatment withdrawal in comparison with children receiving antibacterial monotherapy (n=20). The duration of etiotropic treatment for arresting of the active manifestations of urinary tract infection was lower in patients who were administered the afore-mentioned drug. Immunological monitoring of the urine cytokine status during pidotimod treatment showed that there were signs of T helper 1 cells activation predominance (increase in interferon/interleukin 10 ratio), as well as decrease in granulocyte macrophage colony-stimulating factor concentration, which seems to cause the delayed influence of the drug on the course of urinary tract infection.

C-Fms Signaling Mediates Neurofibromatosis Type-1 Osteoclast Gain-In-Functions

Skeletal abnormalities including osteoporosis and osteopenia occur frequently in both pediatric and adult neurofibromatosis type 1 (NF1) patients. NF1 (Nf1) haploinsufficient osteoclasts and osteoclast progenitors derived from both NF1 patients and Nf1+/− mice exhibit increased differentiation, migration, and bone resorptive capacity in vitro, mediated by hyperactivation of p21Ras in response to limiting concentrations of macrophage-colony stimulating factor (M-CSF). Here, we show that M-CSF binding to its receptor, c-Fms, results in increased c-Fms activation in Nf1+/ − osteoclast progenitors, mediating multiple gain-in-functions through the downstream effectors Erk1/2 and p90RSK. PLX3397, a potent and selective c-Fms inhibitor, attenuated M-CSF mediated Nf1+/− osteoclast migration by 50%, adhesion by 70%, and pit formation by 60%. In vivo, we administered PLX3397 to Nf1 +/− osteoporotic mice induced by ovariectomy (OVX) and evaluated changes in bone mass and skeletal architecture. We found that PLX3397 prevented bone loss in Nf1+/−-OVX mice by reducing osteoclast differentiation and bone resorptive activity in vivo. Collectively, these results implicate the M-CSF/c-Fms signaling axis as a critical pathway underlying the aberrant functioning of Nf1 haploinsufficient osteoclasts and may provide a potential therapeutic target for treating NF1 associated osteoporosis and osteopenia.

Hematopoietic cytokines as tumor markers in gynecological malignancies. A multivariate analysis in epithelial ovarian cancer patients

We investigated plasma levels of selected hematopoietic cytokines: stem cell factor (SCF), granulocyte-macrophage colony-stimulating factor (GM-CSF), granulocyte colony-stimulating factor (G-CSF), and macrophage colony-stimulating factor (M-CSF) and the tumor marker cancer antigen (CA 125) in epithelial ovarian cancer patients as compared with control groups: benign ovarian tumor patients (cysts) and healthy subjects. Cytokine levels were determined by enzyme-linked immunosorbent assay, CA 125 – using the chemiluminescent microparticle immunoassay method. Our results have demonstrated significant differences in the concentrations of M-CSF, G-CSF, SCF (with the exception of GM-CSF), and CA 125 between the groups of ovarian cancer patients, cysts patients, and the healthy controls. When compared with CA 125, M-CSF has equal or higher values of diagnostic sensitivity and specificity. The M-CSF area under the receiver-operating characteristic curve (AUC) was the largest from all the cytokines tested and slightly lower than the AUC of CA 125. These findings suggest the usefulness of M-CSF in diagnosing ovarian cancer, especially when discriminating between cancer and non-carcinoma lesions.

Multipronged attenuation of macrophage-colony stimulating factor signaling by Epstein–Barr virus BARF1

The ubiquitous EBV causes infectious mononucleosis and is associated with several types of cancers. The EBV genome encodes an early gene product, BARF1, which contributes to pathogenesis, potentially through growth-altering and immune-modulating activities, but the mechanisms for such activities are poorly understood. We have determined the crystal structure of BARF1 in complex with human macrophage-colony stimulating factor (M-CSF), a hematopoietic cytokine with pleiotropic functions in development and immune response. BARF1 and M-CSF form a high-affinity, stable, ring-like complex in both solution and the crystal, with a BARF1 hexameric ring surrounded by three M-CSF dimers in triangular array. The binding of BARF1 to M-CSF dramatically reduces but does not completely abolish M-CSF binding and signaling through its cognate receptor FMS. A three-pronged down-regulation mechanism is proposed to explain the biological effect of BARF1 on M-CSF:FMS signaling. These prongs entail control of the circulating and effective local M-CSF concentration, perturbation of the receptor-binding surface of M-CSF, and imposition of an unfavorable global orientation of the M-CSF dimer. Each prong may reduce M-CSF:FMS signaling to a limited extent but in combination may alter M-CSF:FMS signaling dramatically. The downregulating mechanism of BARF1 underlines a viral modulation strategy, and provides a basis for understanding EBV pathogenesis.

The Role of Macrophage Colony-Stimulating Factor in Patients With Acute Myocardial Infarction

We assessed whether macrophage colony-stimulating factor (M-CSF) levels are associated with left ventricular systolic dysfunction (LVSD) in patients with acute myocardial infarction (AMI). We studied 56 patients with AMI (mean age: 67 ± 12 years) and identified those with clinical (Killip class >II) or echocardiographic signs (ejection fraction ≤45%) of LVSD. We evaluated the established cardiovascular risk factors and measured several cardiovascular biomarkers, including M-CSF. Serum M-CSF concentrations (pg/mL) were significantly increased in patients with both clinical and echocardiographic signs of LVSD (460 ± 265 vs 290 ± 210, P = .0103 and 493 ± 299 vs 287 ± 174, P = .0028, respectively). We found a significant inverse association between M-CSF and ejection fraction (r = -.351, P = .0079). Logistic regression analysis revealed that, among all evaluated clinical and biochemical parameters, the stronger predictor of LVSD was M-CSF (odds ratios 2.1, 95% confidence interval 1.1-2.9, P = .0168). This is the first study reporting plasma M-CSF levels as independent determinants of low LV ejection fraction and clinical LV dysfunction in patients with AMI.

Clinical significance of serum macrophage-colony stimulating factor (M-CSF) in esophageal cancer patients and its comparison with classical tumor markers

Hematopoietic growth factors (HGFs), such as macrophage-colony stimulating factor (M-CSF) are produced aberrantly in many malignancies. Esophageal cancer (EC) is characterized by late diagnosis, rapid progression and poor survival. The purpose of the present study was to determine the clinical usefulness of M-CSF in the diagnosis of EC and its histological type - squamous cell cancer of the esophagus (ESCC). The study included 80 patients with EC (54 with ESCC and 26 with adenocarcinoma of the esophagus) and 30 healthy subjects. The serum concentrations of M-CSF, carcinoembryonic antigen (CEA) and squamous cell cancer antigen (SCC-Ag) were determined using immunoenzyme assays. We defined the percentage of increased concentrations of proteins tested and the areas under the receiver-operating characteristics (ROC) curves. In EC and ESCC patients, serum concentrations of M-CSF, CEA and SCC-Ag were significantly higher compared with healthy subjects. Concentrations of M-CSF in both groups analyzed (EC and ESCC) showed a tendency for increases with depth of tumor invasion, the presence of lymph node and distant metastases. The combined use of M-CSF with SCC-Ag increased their percentage of increased concentrations, and this value was higher than for classical tumor markers in both groups analyzed. The area under ROC curve for M-CSF was larger than for CEA in EC patients. Our findings suggest the potential usefulness of serum M-CSF concentrations as a tumor marker for EC, especially in combination with SCC-Ag. However, the diagnostic value of this cytokine may be limited because of its non-specific nature.