Doses Of Macrophage Colony-stimulating Factor Research Articles

Induction of type II collagen expression in M2 macrophages derived from peripheral blood mononuclear cells

The human type II collagen (Col II), specifically expressed in chondrocytes, is a crucial component of the adult hyaline cartilage. We examine the potential of artificial induction of Col II in human peripheral blood mononuclear cells (PBMNCs) as a novel Col II provider. Human PBMNCs were purified and were treated with high doses of macrophage-colony stimulating factor (M-CSF), granulocyte macrophage-colony stimulating factor (GM-CSF), or granulocyte-colony stimulating factor (G-CSF) and examined the Col II expression at indicated days. Quantitative Col II expression was validated by real-time reverse transcriptase-polymerase chain reaction (RT-PCR), immunocytochemistry, and flow cytometry. We demonstrate that monocytes in PBMNCs can be artificially induced to express both Col II proteins and M2 macrophage markers by the high concentration of colony-stimulating factors, especially M-CSF and GM-CSF. The Col II proteins were detected on the cell membrane and in the cytoplasm by flow cytometry and immunocytostaining. Combination with IL-4 provided a synergistic effect with M-CSF/GM-CSF to trigger Col II expression in M2 macrophages. These CD206 and Col II double-expressing cells, named modified macrophages, share M2 macrophages' anti-inflammatory potency. We demonstrated that the modified macrophages could significantly attenuate the inflammatory progress of Complete Freund's adjuvant (CFA)-induced arthritis and collagen-induced arthritis in rodents. Here, we provide the first evidence that a modified macrophage population could ectopically express Col II and control the progress of arthritis in animals.

Opposite effects of different doses of MCSF on ERK phosphorylation and cell proliferation in macrophages.

We had previously shown that murine macrophages expressing v-Fes, the oncogenically activated counterpart of the c-Fes cytoplasmic tyrosine kinase, proliferate independently of Macrophage Colony-Stimulating Factor (MCSF) and that the Extracellular signal-Regulated Kinase (ERK) pathway mediates the mitogenic effect of v-Fes. In this study, the response of c-fes- and v-fes-overexpressing cells to MCSF was investigated. A critical modulation of the activation of Mitogen-activated ERK Kinase (MEK) and ERK based on the MCSF dose was characterized. ERK activation was increased by MCSF doses capable to elicit a mitogenic response (2-5 U/ml). On the contrary, MCSF doses as low as 0.05 U/ml markedly reduced ERK phosphorylation and nuclear content and moderately but significantly reduced cell proliferation. The reduction of MEK and ERK phosphorylation was very rapid, suggesting the involvement of cytosolic phosphatases. Among these, phospho-tyrosine protein phosphatases and phosphoserine/threonine protein phosphatase-2A were found involved. These findings represent the first observation that different doses of the same growth factor, MCSF in particular, can exert opposite effects on cell proliferation by switching on or off ERK signaling.

In vivo and in vitro effects of macrophage colony-stimulating factor (M-CSF) on bronchoalveolar macrophages for antihistoplasmal activity

The in vivo and in vitro effects of M-CSF on bronchoalveolar macrophages (BAM) activity against the intracellular fungal pathogen Histoplasma capsulatum (Hc) were studied. Three days after a single subcutaneous (s.c.) dose of M-CSF (2.5 mg/kg), enhanced ex vivo antifungal activity of BAM was measured. BAM from M-CSF-treated CD-1 mice significantly ( P<0.01) inhibited the intracellular multiplication of He yeast cells in 20 h assays compared to BAM from control mice. This effect was not observed at days 1, 7, 11 or 21 post-treatment. A dose of 5 mg/kg s.c., but not 1 mg/kg, induced similar antifungal activity in BAM by day 3. Peritoneal macrophages (PM) from M-CSF-treated mice did not have enhanced antifungal activity at days and doses tested. BAM could also be activated for antihistoplasmal activity by M-CSF in vitro. M-CSF at 10,000 U/ml for 24 h or 5000 U/ml for 48 h induced significant ( P<0.01) inhibition of intracellular multiplication of Hc. Interferon-gamma (IFN) plus lipopolysaccharide (LPS) activated BAM and PM in vitro to inhibit intracellular multiplication of He ( P<0.001); the antihistoplasmal activity was completely inhibited by N C-monomethyl l-arginine (N-MMA), indicating that an L-arginine-dependent nitric oxide-producing mechanism was operative. N-MMA could not inhibit the antihistoplasmal activity of BAM or PM activated by M-CSF in vitro. The mechanism by which M-CSF-activated macrophages inhibit intracellular multiplication of He remains to be determined.

Interdependence of skeletal sclerosis and elevated circulating levels of 1,25-dihydroxyvitamin D in osteopetrotic (op and tl) rats

Osteopetrosis describes a heterogeneous group of inherited, metabolic bone disorders characterized by reduced bone resorption which coexists with elevated circulating levels of 1,25-dihydroxyvitamin D [1,25(OH) 2D]. To determine whether or not skeletal sclerosis and high concentrations of 1,25(OH) 2D are interdependent, this study used two distinct, nonallelic osteopetrotic mutations in the rat, osteopetrosis ( op) and toothless ( tl). The op rat is a mutation in which skeletal sclerosis can be cured (mutant) or induced (normal) following the transfer of normal or mutant osteoclast progenitors, respectively. Although these procedures are ineffective in rats of tl stock, infusions of pharmacological doses of macrophage colony-stimulating factor (CSF-1) can stimulate bone resorption and eliminate most of the excess skeletal matrix in tl mutants. This study examined the effects of cure/ induction in neonatal mutant/normal rats of op stock and CSF-1 infusions in mutant rats of tl stock on skeletal (bone resorption) and serum [1,25(OH) 2D] parameters as a function of time after treatment. Osteopetrotic mutants transplanted (cured) with normal spleen cells demonstrated cellular changes in osteoclast phenotype within 2–3 days followed by histologic and radiographic evidence for increased bone resorption that culminated in a normal appearance of the skeleton by 4 weeks. The markedly elevated serum levels of 1,25(OH) 2D observed in untreated mutants fell significantly in transplanted mutants by the end of the first week and were similar to those in normal littermates at 3 and 4 weeks. Normal littermates transplanted (induced) with mutant spleen cells showed a progressive increase in skeletal sclerosis paralleled by significant increases in circulating levels of 1,25(OH) 2D. Mutants of tl stock infused with CSF-1 for a period of 2–3 weeks demonstrated a significant reduction in skeletal sclerosis and normalization of serum 1,25(OH) 2D levels. These data clearly demonstrate an interdependence between osteoclast hypofunction and high serum 1,25(OH) 2D concentrations in op and tl rats.

The effect of macrophage colony-stimulating factor on haemopoietic recovery after autologous bone marrow transplantation.

Macrophage colony-stimulating factor (M-CSF) is active in the late stages of monocyte maturation, activates mature monocyte-macrophages and enhances their production of various other cytokines. We have examined the effects of a 21 d course of escalating doses of M-CSF purified from human urine (hM-CSF) on recovery following autologous bone marrow transplantation (ABMT) in 20 patients with malignant lymphomas. Four patients were treated at each dose level of 4, 8, 16, 32 and 64 x 10(6) U/m2/d and results compared to 46 concurrent controls. There was no significant difference in recovery to an absolute neutrophil count (ANC) of 0.5 x 10(9)/l (median 20 d in hM-CSF group versus 22 in controls) or in recovery of platelets to 50 x 10(9)/l (32 d versus 39 d, 0.05 less than P less than 0.1); hM-CSF patients received a median of 81 platelet units following ABMT (controls 112 units, P = NS). hM-CSF patients had a median of 5.5 d with fever greater than 37.5 degrees C (control 8, P = NS), received parenteral antibiotics for 14.5 d (control 17, P = NS) and had a 50% incidence of bacteraemia (control 48%). hM-CSF treated patients were discharged by a median of day 29 following transplantation (control 33, P less than 0.05). Platelet and neutrophil recovery correlated significantly with the number of marrow mononuclear cells (MNC) reinfused in the hM-CSF group (P = 0.05 and P = 0.014 respectively) but not in controls. Subgroup analysis showed that hM-CSF patients receiving greater than 2 x 10(8) MNC/kg body weight reached an ANC of 0.5 x 10(9)/l by a median of day 16.5 (control 18.5, NS), became platelet transfusion independent by day 17 (control 29, P less than 0.05) and reached a platelet count of 50 x 10(9)/l by day 21 (control 40, P less than 0.05). No significant toxicity attributable to hM-CSF treatment was seen. These results suggest that hM-CSF accelerates platelet recovery following ABMT and that relatively large marrow innocula are required to see this effect.