FRINK Linked Data Fragments server

Matches in SemOpenAlex for { <https://semopenalex.org/work/W1996959454> ?p ?o ?g. }

• W1996959454 endingPage "1970" @default.
• W1996959454 startingPage "1962" @default.
• W1996959454 abstract "Previous studies have shown that colony stimulating factor-1 (CSF-1) deficiency dramatically reduced atherogenesis in mice. In this report we investigate this mechanism and explore a therapeutic avenue based on inhibition of CSF-1 signaling. Lesions from macrophage colony stimulating factor-1 (Csf1)+/− mice showed increased numbers of apoptotic macrophages, decreased overall macrophage content, and inflammation. In vitro studies indicated that CSF-1 is chemotactic for monocytes. Bone marrow transplantation studies suggested that vascular cell-derived, rather than macrophage-derived, CSF-1 is responsible for the effect on atherosclerosis. Consistent with previous studies, CSF-1 affected lesion development in a dose-dependent manner, suggesting that pharmacological inhibition of CSF-1 might achieve similar results. Indeed, we observed that treatment of hyperlipidemic mice with a CSF-1 receptor kinase inhibitor inhibited plaque progression. This observation was accompanied by a reduction in the expression of adhesion factors (ICAM-1), macrophage markers (F4/80), inflammatory cytokines (Il-6, Il-1β), and macrophage matrix degradation enzymes (MMP-9). We conclude that the M-CSF pathway contributes to monocyte recruitment and macrophage survival and that this pathway is a potential target for therapeutic intervention. Previous studies have shown that colony stimulating factor-1 (CSF-1) deficiency dramatically reduced atherogenesis in mice. In this report we investigate this mechanism and explore a therapeutic avenue based on inhibition of CSF-1 signaling. Lesions from macrophage colony stimulating factor-1 (Csf1)+/− mice showed increased numbers of apoptotic macrophages, decreased overall macrophage content, and inflammation. In vitro studies indicated that CSF-1 is chemotactic for monocytes. Bone marrow transplantation studies suggested that vascular cell-derived, rather than macrophage-derived, CSF-1 is responsible for the effect on atherosclerosis. Consistent with previous studies, CSF-1 affected lesion development in a dose-dependent manner, suggesting that pharmacological inhibition of CSF-1 might achieve similar results. Indeed, we observed that treatment of hyperlipidemic mice with a CSF-1 receptor kinase inhibitor inhibited plaque progression. This observation was accompanied by a reduction in the expression of adhesion factors (ICAM-1), macrophage markers (F4/80), inflammatory cytokines (Il-6, Il-1β), and macrophage matrix degradation enzymes (MMP-9). We conclude that the M-CSF pathway contributes to monocyte recruitment and macrophage survival and that this pathway is a potential target for therapeutic intervention. Colony stimulating factor-1 (CSF-1) regulates monocyte/macrophage survival, differentiation, proliferation (1.Tushinski R.J. Oliver I.T. Guilbert L.J. Tynan P.W. Warner J.R. Stanley E.R. Survival of mononuclear phagocytes depends on a lineage-specific growth factor that the differentiated cells selectively destroy.Cell. 1982; 28: 71-81Abstract Full Text PDF PubMed Scopus (485) Google Scholar, 2.Stanley E.R. Guilbert L.J. Tushinski R.J. Bartelmez S.H. CSF-1–a mononuclear phagocyte lineage-specific hemopoietic growth factor.J. Cell. Biochem. 1983; 21: 151-159Crossref PubMed Scopus (423) Google Scholar, 3.Kodama H. Yamasaki A. Nose M. Niida S. Ohgame Y. Abe M. Kumegawa M. Suda T. Congenital osteoclast deficiency in osteopetrotic (op/op) mice is cured by injections of macrophage colony-stimulating factor.J. Exp. Med. 1991; 173: 269-272Crossref PubMed Scopus (333) Google Scholar, 4.Sherr C.J. Rettenmier C.W. Roussel M.F. Macrophage colony-stimulating factor, CSF-1, and its proto-oncogene-encoded receptor.Cold Spring Harb. Symp. Quant. Biol. 1988; 53: 521-530Crossref PubMed Google Scholar), and migration (5.Wang J.M. Griffin J.D. Rambaldi A. Chen Z.G. Mantovani A. Induction of monocyte migration by recombinant macrophage colony-stimulating factor.J. Immunol. 1988; 141: 575-579PubMed Google Scholar, 6.Bober L.A. Grace M.J. Pugliese-Sivo C. Rojas-Triana A. Sullivan L.M. Narula S.K. The effects of colony stimulating factors on human monocyte cell function.Int. J. Immunopharmacol. 1995; 17: 385-392Crossref PubMed Scopus (33) Google Scholar) by activating a signaling cascade mediated by its receptor, the tyrosine kinase proto-oncogene c-fms (also known as Csf1r). Interleukin-34 (IL-34) has been recently identified as another ligand for CSF1-R; however, its role in atherosclerosis has yet to be elucidated. Inflammatory disorders that display elevated levels of CSF-1 include arthritis, obesity, and atherosclerosis (7.Chitu V. Stanley E.R. Colony-stimulating factor-1 in immunity and inflammation.Curr. Opin. Immunol. 2006; 18: 39-48Crossref PubMed Scopus (470) Google Scholar). The potential involvement of CSF-1 in atherosclerosis was first suggested by the observation that CSF-1 is induced in endothelial cells by treatment with oxidized lipids (8.Rajavashisth T.B. Andalibi A. Territo M.C. Berliner J.A. Navab M. Fogelman A.M. Lusis A.J. Induction of endothelial cell expression of granulocyte and macrophage colony-stimulating factors by modified low-density lipoproteins.Nature. 1990; 344: 254-257Crossref PubMed Scopus (611) Google Scholar) and is expressed at high levels in atherosclerotic lesions (8.Rajavashisth T.B. Andalibi A. Territo M.C. Berliner J.A. Navab M. Fogelman A.M. Lusis A.J. Induction of endothelial cell expression of granulocyte and macrophage colony-stimulating factors by modified low-density lipoproteins.Nature. 1990; 344: 254-257Crossref PubMed Scopus (611) Google Scholar, 9.Rosenfeld M.E. Yla-Herttuala S. Lipton B.A. Ord V.A. Witztum J.L. Steinberg D. Macrophage colony-stimulating factor mRNA and protein in atherosclerotic lesions of rabbits and humans.Am. J. Pathol. 1992; 140: 291-300PubMed Google Scholar). Subsequently, it was shown that osteopetrotic (op/op) mice carrying a Csf1 null mutation, either on an apolipoprotein E (apoE)−/− or a low density lipoprotein receptor null (LDLR−/−) background, showed a dramatic decrease in the size of atherosclerotic lesions (10.Qiao J.H. Tripathi J. Mishra N.K. Cai Y. Tripathi S. Wang X.P. Imes S. Fishbein M.C. Clinton S.K. Libby P. et al.Role of macrophage colony-stimulating factor in atherosclerosis: studies of osteopetrotic mice.Am. J. Pathol. 1997; 150: 1687-1699PubMed Google Scholar, 11.Rajavashisth T. Qiao J.H. Tripathi S. Tripathi J. Mishra N. Hua M. Wang X.P. Loussararian A. Clinton S. Libby P. et al.Heterozygous osteopetrotic (op) mutation reduces atherosclerosis in LDL receptor-deficient mice.J. Clin. Invest. 1998; 101: 2702-2710Crossref PubMed Scopus (211) Google Scholar, 12.Smith J.D. Trogan E. Ginsberg M. Grigaux C. Tian J. Miyata M. Decreased atherosclerosis in mice deficient in both macrophage colony-stimulating factor (op) and apolipoprotein E.Proc. Natl. Acad. Sci. USA. 1995; 92: 8264-8268Crossref PubMed Scopus (575) Google Scholar). Several significant issues concerning the role of CSF-1 in atherogenesis remain unresolved. First, the mechanism by which the CSF-1 deficiency contributes to lesion development remains unclear. Because CSF-1 influences monocyte/macrophage growth and survival, likely mechanisms include decreased numbers of circulating monocytes; decreased monocyte recruitment to the artery wall; decreased monocyte/macrophage proliferation; decreased macrophage uptake of oxidized lipids; and increased monocyte/macrophage foam cell necrosis/apoptosis. Second, the source of the CSF-1 critical for lesion formation is unclear. Both macrophages and endothelial cells (EC) appear to be likely candidates as CSF-1 is expressed by both cell types and expression is dramatically induced in EC by oxidized LDL and by proinflammatory molecules, such as bacterial lipopolysaccaride (8.Rajavashisth T.B. Andalibi A. Territo M.C. Berliner J.A. Navab M. Fogelman A.M. Lusis A.J. Induction of endothelial cell expression of granulocyte and macrophage colony-stimulating factors by modified low-density lipoproteins.Nature. 1990; 344: 254-257Crossref PubMed Scopus (611) Google Scholar). CSF-1 has previously been shown by immunohistochemistry to be abundantly produced in human and rabbit atherosclerotic lesions but not in the normal vessel wall (9.Rosenfeld M.E. Yla-Herttuala S. Lipton B.A. Ord V.A. Witztum J.L. Steinberg D. Macrophage colony-stimulating factor mRNA and protein in atherosclerotic lesions of rabbits and humans.Am. J. Pathol. 1992; 140: 291-300PubMed Google Scholar, 13.Clinton S.K. Underwood R. Hayes L. Sherman M.L. Kufe D.W. Libby P. Macrophage colony-stimulating factor gene expression in vascular cells and in experimental and human atherosclerosis.Am. J. Pathol. 1992; 140: 301-316PubMed Google Scholar). Because CSF-1 deficiency has such a dramatic impact on atherosclerosis, we have been interested in the possibility that pharmacologic inhibition of CSF-1 signaling could be a useful therapeutic intervention. We have examined the effects of a CSF-1 receptor kinase inhibitor (GW2580) (14.Conway J.G. McDonald B. Parham J. Keith B. Rusnak D.W. Shaw E. Jansen M. Lin P. Payne A. Crosby R.M. et al.Inhibition of colony-stimulating-factor-1 signaling in vivo with the orally bioavailable cFMS kinase inhibitor GW2580.Proc. Natl. Acad. Sci. USA. 2005; 102: 16078-16083Crossref PubMed Scopus (191) Google Scholar) on inflammation and atherosclerosis. Csf1 heterozygous mice on a C57BL/6JxC3HeB/FeJ mixed genetic background were purchased from the Jackson Laboratory (Bar Harbor, ME) and backcrossed for ten generations to C57BL/6J mice, at which point the mice were crossed to LDLR−/− on the same background. At approximately 10 weeks of age the mice were placed on a Western-type diet (TD 88137, Teklad, Madison, WI) for 13 weeks before sacrifice. The Animal Research Committee of the University of California at Los Angeles approved all animal work. GW2580 was synthesized as previously described (14.Conway J.G. McDonald B. Parham J. Keith B. Rusnak D.W. Shaw E. Jansen M. Lin P. Payne A. Crosby R.M. et al.Inhibition of colony-stimulating-factor-1 signaling in vivo with the orally bioavailable cFMS kinase inhibitor GW2580.Proc. Natl. Acad. Sci. USA. 2005; 102: 16078-16083Crossref PubMed Scopus (191) Google Scholar). The compound (or carrier) was administered orally at 80 mg/kg twice a day for 8 weeks to 8-week-old low density lipoprotein receptor (LDLR)−/− female mice. Atherosclerotic lesions in the proximal aorta and aortic root were measured as previously reported (15.Mehrabian M. Allayee H. Wong J. Shi W. Wang X.P. Shaposhnik Z. Funk C.D. Lusis A.J. Identification of 5-lipoxygenase as a major gene contributing to atherosclerosis susceptibility in mice.Circ. Res. 2002; 91: 120-126Crossref PubMed Scopus (374) Google Scholar). The ascending and descending aorta was pinned out en face and stained with Oil red O as in Tangirala et al. (16.Tangirala R.K. Rubin E.M. Palinski W. Quantitation of atherosclerosis in murine models: correlation between lesions in the aortic origin and in the entire aorta, and differences in the extent of lesions between sexes in LDL receptor-deficient and apolipoprotein E-deficient mice.J. Lipid Res. 1995; 36: 2320-2328Abstract Full Text PDF PubMed Google Scholar). Lesion surface area and total aortic surface area were measured using Image Pro Plus (Media Cybernetics). Frozen sections from the proximal aorta were stained for plaque composition by a Movat pentachrome stain, macrophages (rat anti-mouse MOMA-2, BD Biosciences, San Jose, CA) and proliferating cells (rabbit-anti mouse Ki67, Abcam). Mice were injected intraperitoneally with 1 ml of 3% brewer's yeast thioglycolate four days before sacrifice. Cells were isolated by flushing the peritoneal cavity with cold PBS. Red blood cells were lysed and peritoneal cells were counted. Monocyte migration was determined in vitro using a human artery wall coculture model (17.Navab M. Hama S.Y. Cooke C.J. Anantharamaiah G.M. Chaddha M. Jin L. Subbanagounder G. Faull K.F. Reddy S.T. Miller N.E. et al.Normal high density lipoprotein inhibits three steps in the formation of mildly oxidized low density lipoprotein: step 1.J. Lipid Res. 2000; 41: 1481-1494Abstract Full Text Full Text PDF PubMed Google Scholar). The ApopTag Fluorescein In Situ Apoptosis Detection Kit (Millipore, Billerica, MA), utilizing a terminal deoxynucleotidyl transferase (TdT)–based technique, was used to quantitate apoptosis within atherosclerotic lesions of the aortic root. Bone marrow from Csf1+/+ and Csf1+/− mice on the C57BL/6J background and Csf1+/+ and Csf1−/− mice on a mixed C57BL/6J x 129T2/SvEMsJ background was collected. Bone marrow from this mixed background was used because we were unable to obtain Csf1−/− mice on an inbred B6 background. The 129 strain was chosen because its haplotype is compatible with B6 mice. Eight-week-old recipients were lethally irradiated and injected via the tail vein with 107 bone marrow cells as previously described (17.Navab M. Hama S.Y. Cooke C.J. Anantharamaiah G.M. Chaddha M. Jin L. Subbanagounder G. Faull K.F. Reddy S.T. Miller N.E. et al.Normal high density lipoprotein inhibits three steps in the formation of mildly oxidized low density lipoprotein: step 1.J. Lipid Res. 2000; 41: 1481-1494Abstract Full Text Full Text PDF PubMed Google Scholar). Five weeks after transplantation the animals were placed on a Western-type diet for 12 weeks. Leukocyte DNA was isolated to confirm the presence of the Csf1 null allele or the presence of the Sry gene by PCR as appropriate. Total RNA was isolated using an RNEASY kit (Qiagen, Valencia, CA). cDNA was synthesized with iScript cDNA Synthesis Kit (Biorad, Hercules, CA). Quantitative PCR was performed on an Applied Biosystems 7700 unit using Platinum SYBR Green qPCR Supermix UDG (Invitrogen, Carlsbad, CA). Samples were analyzed in duplicate and normalized to β(2)-microglobulin (B2M) expression. B2M, a component of the MHC I complex, is an ubiquitous and stably expressed factor. Data were expressed as mean +/−SEM. Statistical analyses were performed using the nonparametric Mann Whitney test (Statview, SAS Institute, Cary, NC) for all comparisons. Lesion data were displayed as a box plot and whiskers, the central line representing the overall median, the bottom of the box representing the median of the first quartile of the data set, and the top of the box representing the median third quartile of the data set. Open circles represent outliers beyond the 9th and 91st percentiles. To study the mechanism by which a CSF-1 deficiency contributes to atherosclerosis, we sought to place the Csf1 null mutation on an inbred genetic background. For this, we repeatedly crossed the mutation, originally on a mixed C57BL/6JxC3HeB/FeJ background, to inbred C57BL/6J mice. We felt this was important as C3H mice are highly resistant to atherosclerosis and nearly a dozen major loci contribute to the differences in susceptibility between C57BL/6 and C3H mice on an apoE null background (18.Wang S.S. Schadt E.E. Wang H. Wang X. Ingram-Drake L. Shi W. Drake T.A. Lusis A.J. Identification of pathways for atherosclerosis in mice: integration of quantitative trait locus analysis and global gene expression data.Circ. Res. 2007; 101: e11-e30Crossref PubMed Scopus (92) Google Scholar). After 10 generations of backcrossing, we intercrossed heterozygous mice. Over 120 mice from this cross were genotyped, which resulted in a ratio that was greatly skewed from the expected 1:2:1 ratio. Approximately equal numbers of +/+ and +/− mice were observed; only 2 mice were of the −/− genotype. Thus, both the heterozygous and homozygous null genotypes were associated with dramatically reduced viability. Even on a mixed genetic background, Csf1−/− mice had reduced size and weight at birth as well as osteopetrosis and a lack of tooth eruption (19.Wiktor-Jedrzejczak W. Bartocci A. Ferrante Jr., A.W. Ahmed-Ansari A. Sell K.W. Pollard J.W. Stanley E.R. Total absence of colony-stimulating factor 1 in the macrophage-deficient osteopetrotic (op/op) mouse.Proc. Natl. Acad. Sci. USA. 1990; 87: 4828-4832Crossref PubMed Scopus (892) Google Scholar, 20.Yoshida H. Hayashi S. Kunisada T. Ogawa M. Nishikawa S. Okamura H. Sudo T. Shultz L.D. The murine mutation osteopetrosis is in the coding region of the macrophage colony stimulating factor gene.Nature. 1990; 345: 442-444Crossref PubMed Scopus (1531) Google Scholar). We chose to use primarily heterozygous mice in this study. While both male and female mice were examined, we present here our analysis on female mice. The male data (supplementary data at www.jlr.org) yielded similar conclusions, although there were some significant differences. Examination of the aortic root by immunostaining clearly revealed decreased macrophage content and a reduced the rate of plaque formation in female Csf1–deficient mice. Intimal lesion macrophage content decreased by 50% (Fig. 1) in female Csf1+/− LDLR−/− mice compared with Csf1+/+ LDLR−/− mice. Movat staining showed that about 45% of the lesion area consisted of matrix components, including collagen and proteoglycans (supplementary Table I). Csf1+/− LDLR−/− female mice showed a 40% decrease in proximal aorta atherosclerosis (Fig. 2). This decrease was not observed in the thoracic and abdominal aorta of female Csf1+/− mice, as measured by en face staining of lipids (supplementary Fig. I-A). We observed no differences in plasma lipids, circulating monocytes, overall number of cells per unit of lesion area (data not shown), number of proliferating cells (supplementary text and Fig. II-A), fibrous caps, or prominent lipid cores per aortic root section (Table 1, supplementary Tables I, II).Fig. 2Effect of a CSF-1 deficiency on atherosclerotic lesions in the proximal aorta. Atherosclerotic lesions in aortic root sections of Csf1+/+ and −/− mice were quantitated by lipid staining with Oil Red O (A) and after bone marrow transplantations (C). Aortic root lesions were stained with Movat Pentachrome to better characterize relative plaque composition. Representative lesion sections are shown in (B) with collagen in yellow, SMCs in red, and proteoglycans in blue. The lesion data are presented as box plots (see “Materials and Methods”). (∗∗∗P < 0.001, ∗∗P < 0.01). CSF-1, colony stimulating factor-1; wt, wild-type at the Csf1 locus; het, heterozygous at the Csf1 locus; ko, null at the Csf1 locus.View Large Image Figure ViewerDownload Hi-res image Download (PPT)TABLE 1Circulating monocyte levels measures by flow cytometryCSF-1+/+ LDLR−/−CSF-1+/− LDLR−/−FemalesMonocytes1.36 ± 0.352.05 ± 0.43(CD115+)n = 6n = 5% of LeukocytesValues are expressed as mean ±SEM.Abbreviations: CSF-1, colony stimulating factor-1; LDLR, low density lipoprotein receptor. Open table in a new tab Values are expressed as mean ±SEM. Abbreviations: CSF-1, colony stimulating factor-1; LDLR, low density lipoprotein receptor. As discussed above, monocytes/macrophages are capable of abundant CSF-1 expression. To test whether monocyte/macrophage-derived CSF-1 contributed to lesion development, we conducted bone marrow transplantation experiments. We transplanted bone marrow from Csf1+/+ and Csf1−/− donors into lethally irradiated LDLR−/− recipients and placed the animals on a 12-week Western diet. No significant differences were detected in aortic root atherosclerosis (Fig. 2), plasma CSF-1 levels, or circulating monocyte counts (supplementary Table II) between animals receiving Csf1+/+ or Csf1−/− bone marrow. We also performed the reciprocal experiments. We transplanted Csf1+/+ bone marrow into lethally irradiated Csf1+/− LDLR−/− mice and placed them on the same diet regimen as before. Female mice exhibited a 50% decrease in aortic root atherosclerosis (Fig. 2C) and a 35% decrease in plasma CSF-1 levels but no decrease in circulating monocyte counts (supplementary Table III). In this experiment, the male Csf1+/− mice showed a trend toward decreased lesion size that did not reach statistical significance (data not shown). We conclude that the levels of artery wall–derived CSF-1 is most important in mediating the effect of CSF-1 on atherosclerosis and that an absence of macrophage-derived CSF-1 has little or no impact on atherosclerosis. Csf1+/− LDLR−/− mice demonstrated a 7-fold decrease in aortic Csf1 expression and a 3-fold decrease in SRA expression (Fig. 3). One would expect a 2-fold decrease in Csf1 expression when examining heterozygous mice, but as macrophages express this cytokine themselves, the large decrease we observed in aortic Csf1 expression probably reflects the decreased macrophage content (Fig. 1) and atherosclerosis (Fig. 2) of Csf1+/− LDLR−/− mice. SRA is known to be upregulated by Csf1 (21.Guidez F. Li A.C. Horvai A. Welch J.S. Glass C.K. Differential utilization of Ras signaling pathways by macrophage colony-stimulating factor (CSF) and granulocyte-macrophage CSF receptors during macrophage differentiation.Mol. Cell. Biol. 1998; 18: 3851-3861Crossref PubMed Scopus (33) Google Scholar), but in this case, decreased SRA expression is attributable to decreased macrophage content of the lesion. No significant changes in CD36, KC, or MCP-1 expression were detected (data not shown); however, those cDNAs were detected at levels so low in the control arterial samples that detecting further decreases in expression in Csf1–deficient mice would be highly unlikely. We examined the possible role of CSF-1 in monocyte recruitment using an in vitro monocyte migration assay (17.Navab M. Hama S.Y. Cooke C.J. Anantharamaiah G.M. Chaddha M. Jin L. Subbanagounder G. Faull K.F. Reddy S.T. Miller N.E. et al.Normal high density lipoprotein inhibits three steps in the formation of mildly oxidized low density lipoprotein: step 1.J. Lipid Res. 2000; 41: 1481-1494Abstract Full Text Full Text PDF PubMed Google Scholar) and an in vivo peritoneal macrophage recruitment assay (supplementary Fig. III-A). Addition of a CSF-1 neutralizing antibody to an in vitro assay consisting of cocultures of endothelial and smooth muscle cells significantly decreased monocyte migration in response to oxidized lipids, whereas control antiserum had no effect. Consistent with this, peritoneal cavity monocyte recruitment in response to thioglycolate exhibited a significant decrease in Csf1+/− LDLR−/− animals. These experiments support the idea that CSF-1 has a chemotactic role in the artery wall and that the haploinsufficiency of Csf1 in Csf1+/− animals can alter monocyte migration in the context of atherosclerosis. We did not detect a difference in circulating levels of CD115+ (CSF-1 receptor expressing) monocytes (Table 1, supplementary Fig. III-C). The decreased macrophage content we observed in atherosclerotic lesions from Csf1–deficient mice raised the possibility of an effect on macrophage apoptosis. We quantitated apoptosis in lesions by measuring DNA fragmentation using terminal deoxynucleotidyl transferase–mediated dUTP nick end labeling (TUNEL) staining. The number of apoptotic nuclei varied from 0 to 22 per section in each group and overlapped almost exclusively with lesion areas positive for the macrophage marker MOMA-2 (Fig. 4A–B, supplementary Fig. VI-A, B). Female Csf1+/− lesion sections did not show an increase in apoptotic cell content relative to lesion. However, after normalizing for the number of apoptotic cells by the percentage of MOMA-2–positive lesion area, we observed approximately 2-fold increased apoptosis in Csf1+/− LDLR−/− mouse lesions (P < 0.05) (Fig. 4D). Additional studies were conducted to determine cell survival using mouse bone marrow derived macrophages from either Csf1+/+ or Csf1+/− mice. Cells were cultured for six days in regular media or media supplemented with recombinant CSF-1. We observed that both groups of cells treated with CSF-1 continued to proliferate over the six days and displayed a spread out morphology typified by various cellular projections. In contrast to that, cells starved of CSF-1 displayed a much more rounded morphology and appeared not to proliferate at all. Their numbers declined precipitously after six days in culture compared with cells not starved of CSF-1 (data not shown). On the basis of the clear dose-dependent inhibitory effect of a CSF-1 reduction on lesion formation, we tested the effect of blocking CSF-1 signaling by inhibiting the intrinsic kinase activity of the CSF-1 receptor with a highly selective, orally bioavailable, small-molecule kinase inhibitor GW2580 (14.Conway J.G. McDonald B. Parham J. Keith B. Rusnak D.W. Shaw E. Jansen M. Lin P. Payne A. Crosby R.M. et al.Inhibition of colony-stimulating-factor-1 signaling in vivo with the orally bioavailable cFMS kinase inhibitor GW2580.Proc. Natl. Acad. Sci. USA. 2005; 102: 16078-16083Crossref PubMed Scopus (191) Google Scholar). We initially detected the ability of this compound to inhibit LDL- or MCP-1–mediated monocyte migration in a dose-dependent manner using an artery wall coculture model (supplementary Fig. IV-A). This suggested there was potential for the compound to be effective in inhibiting atherogenesis in vivo. The inhibitor was dosed orally twice a day at 80 mg/kg into LDLR−/− female mice for 8 weeks. This dose was chosen based on previous work (14.Conway J.G. McDonald B. Parham J. Keith B. Rusnak D.W. Shaw E. Jansen M. Lin P. Payne A. Crosby R.M. et al.Inhibition of colony-stimulating-factor-1 signaling in vivo with the orally bioavailable cFMS kinase inhibitor GW2580.Proc. Natl. Acad. Sci. USA. 2005; 102: 16078-16083Crossref PubMed Scopus (191) Google Scholar) indicating that free drug levels in the plasma would remain within the IC50 range for suppression of monocyte proliferation while maintaining 100-fold selectivity for kinase inhibition. Lesion size was reduced ∼40% (P < 0.05), and relative plasma PON activity was elevated 28% (P < 0.05) (Fig. 5). Using the same coculture model mentioned previously, we observed that HDL from the group treated with GW2580 retained the protective capacity to inhibit LDL-mediated monocyte migration while HDL from control mice lost this ability (supplementary Fig. IV-C). No changes in plasma lipid levels were detected (supplementary Fig. V). GW250 was added to cultured peritoneal macrophages to determine if phosphorylation of Akt, an event known to occur downstream of CSF-1R signaling and an important factor in cell survival/proliferation, had been altered. Thioglycolate-elicited peritoneal macrophages isolated from C57BL6/J mice were cultured for one week in regular media, media supplemented with 10 ng/ml of recombinant CSF-1 (as a positive control), or with 1 μM of the CSF1-R kinase inhibitor GW250. This concentration of inhibitor should selectively inhibit all endogenous signaling only through this receptor. Western blots of cell lysates were probed for phospho-Akt and total Akt levels. It was observed that phospho-Akt levels decreased 89% using GW2580 after normalization to total Akt levels while increasing 155% upon addition of recombinant CSF-1 (supplementary Fig. VII). To better understand the anti-inflammatory effects of GW2580, inflammatory gene expression was determined in the atherosclerotic aorta and the liver. As in the Csf1+/− mouse lesions, 70%–80% reductions were observed in the tissue macrophage–specific marker F4/80 (P < 0.01), the pan-monocyte/macrophage marker CSF1-R (the CSF-1 receptor) (P < 0.001), and the scavenger receptor SRA (P < 0.01) (Fig. 6A). Matrix metallopeptidase-9 (MMP-9) expression, an enzyme secreted by macrophages that can degrade the matrix and fibrous cap causing lesion destabilization, declined ∼90% (P < 0.001). ICAM-1 and E-Selectin, both factors expressed by the endothelium early in plaque formation and involved in the firm adhesion of monocytes to the artery wall prior to their entry, showed 70%–80% reduced expression in the CSF-1R inhibitor–treated group. Urokinase plasminogen activator receptor (uPAR), a direct target of CSF-1 signaling, was significantly downregulated as well (Fig. 6B). In contrast to the aorta, hepatic CSF-1R expression tripled (P < 0.05) while F4/80 levels declined 50% (Fig. 6C), suggesting that while the overall macrophage content of liver decreased, there appears to be a feedback loop linking the inhibition of CSF-1 signaling with increased expression of CSF-1 receptor in the remaining tissue macrophages. The expression of other key inflammatory mediators and markers of inflammatory macrophages, such as IL-6 and IL-1 β, decreased by 50%–80% in the liver. Hepatic CSF-1 expression itself declined 50% (P < 0.05). Genetic deficiencies of CSF-1 or its receptor are known to increase bone density and decreasing adiposity. We studied adiposity using NMR and bone density using DEXA in response to GW2580 treatment. Except for a small change in adiposity (from 19.1% to 22.5%, P < 0.05), no differences were observed. We also found no changes in food intake or blood monocyte counts in mice treated with the inhibitor (data not shown). Our studies with Csf1+/− LDLR−/− mice showed that the effect of CSF-1 on atherosclerosis was dependent on decreased artery wall–derived CSF-1, rather than monocyte/macrophage-derived CSF-1. It resulted in decreased lesional macrophage content and increased lesional macrophage apoptosis. Also, our studies with a specific CSF-1 receptor kinase inhibitor (GW2580) suggest that pharmacologic inhibition of CSF-1 signaling may be a promising therapy for atherosclerosis. Studies of Csf1-deficient mice on ApoE−/− (12.Smith J.D. Trogan E. Ginsberg M. Grigaux C. Tian J. Miyata M. Decreased atherosclerosis in mice deficient in both macrophage colony-stimulating factor (op) and apolipoprotein E.Proc. Natl. Acad. Sci. USA. 1995; 92: 8264-8268Crossref P" @default.
• W1996959454 created "2016-06-24" @default.
• W1996959454 creator A5024741961 @default.
• W1996959454 creator A5055586327 @default.
• W1996959454 creator A5082624685 @default.
• W1996959454 date "2010-07-01" @default.
• W1996959454 modified "2023-10-10" @default.
• W1996959454 title "Arterial colony stimulating factor-1 influences atherosclerotic lesions by regulating monocyte migration and apoptosis" @default.
• W1996959454 cites W1550691023 @default.
• W1996959454 cites W1814670478 @default.
• W1996959454 cites W1880318558 @default.
• W1996959454 cites W1886864374 @default.
• W1996959454 cites W1964698497 @default.
• W1996959454 cites W1965696083 @default.
• W1996959454 cites W1970264868 @default.
• W1996959454 cites W1976689062 @default.
• W1996959454 cites W1997320875 @default.
• W1996959454 cites W2004789344 @default.
• W1996959454 cites W2016581439 @default.
• W1996959454 cites W2022122015 @default.
• W1996959454 cites W2024725966 @default.
• W1996959454 cites W2025162592 @default.
• W1996959454 cites W2026236910 @default.
• W1996959454 cites W2041138285 @default.
• W1996959454 cites W2042662552 @default.
• W1996959454 cites W2045177756 @default.
• W1996959454 cites W2054492489 @default.
• W1996959454 cites W2054753294 @default.
• W1996959454 cites W2062798105 @default.
• W1996959454 cites W2094402463 @default.
• W1996959454 cites W2099500890 @default.
• W1996959454 cites W2108014410 @default.
• W1996959454 cites W2109807835 @default.
• W1996959454 cites W2112187949 @default.
• W1996959454 cites W2123168196 @default.
• W1996959454 cites W2130003736 @default.
• W1996959454 cites W2158250457 @default.
• W1996959454 cites W2339541228 @default.
• W1996959454 doi "https://doi.org/10.1194/jlr.m005215" @default.
• W1996959454 hasPubMedCentralId "https://www.ncbi.nlm.nih.gov/pmc/articles/2882747" @default.
• W1996959454 hasPubMedId "https://pubmed.ncbi.nlm.nih.gov/20194110" @default.
• W1996959454 hasPublicationYear "2010" @default.
• W1996959454 type Work @default.
• W1996959454 sameAs 1996959454 @default.
• W1996959454 citedByCount "53" @default.
• W1996959454 countsByYear W19969594542012 @default.
• W1996959454 countsByYear W19969594542013 @default.
• W1996959454 countsByYear W19969594542014 @default.
• W1996959454 countsByYear W19969594542015 @default.
• W1996959454 countsByYear W19969594542016 @default.
• W1996959454 countsByYear W19969594542018 @default.
• W1996959454 countsByYear W19969594542019 @default.
• W1996959454 countsByYear W19969594542020 @default.
• W1996959454 countsByYear W19969594542021 @default.
• W1996959454 countsByYear W19969594542022 @default.
• W1996959454 countsByYear W19969594542023 @default.
• W1996959454 crossrefType "journal-article" @default.
• W1996959454 hasAuthorship W1996959454A5024741961 @default.
• W1996959454 hasAuthorship W1996959454A5055586327 @default.
• W1996959454 hasAuthorship W1996959454A5082624685 @default.
• W1996959454 hasBestOaLocation W19969594541 @default.
• W1996959454 hasConcept C126322002 @default.
• W1996959454 hasConcept C134018914 @default.
• W1996959454 hasConcept C142724271 @default.
• W1996959454 hasConcept C185592680 @default.
• W1996959454 hasConcept C190283241 @default.
• W1996959454 hasConcept C2781184567 @default.
• W1996959454 hasConcept C502942594 @default.
• W1996959454 hasConcept C55493867 @default.
• W1996959454 hasConcept C71924100 @default.
• W1996959454 hasConcept C86803240 @default.
• W1996959454 hasConcept C95444343 @default.
• W1996959454 hasConceptScore W1996959454C126322002 @default.
• W1996959454 hasConceptScore W1996959454C134018914 @default.
• W1996959454 hasConceptScore W1996959454C142724271 @default.
• W1996959454 hasConceptScore W1996959454C185592680 @default.
• W1996959454 hasConceptScore W1996959454C190283241 @default.
• W1996959454 hasConceptScore W1996959454C2781184567 @default.
• W1996959454 hasConceptScore W1996959454C502942594 @default.
• W1996959454 hasConceptScore W1996959454C55493867 @default.
• W1996959454 hasConceptScore W1996959454C71924100 @default.
• W1996959454 hasConceptScore W1996959454C86803240 @default.
• W1996959454 hasConceptScore W1996959454C95444343 @default.
• W1996959454 hasIssue "7" @default.
• W1996959454 hasLocation W19969594541 @default.
• W1996959454 hasLocation W19969594542 @default.
• W1996959454 hasLocation W19969594543 @default.
• W1996959454 hasLocation W19969594544 @default.
• W1996959454 hasLocation W19969594545 @default.
• W1996959454 hasOpenAccess W1996959454 @default.
• W1996959454 hasPrimaryLocation W19969594541 @default.
• W1996959454 hasRelatedWork W1966504330 @default.
• W1996959454 hasRelatedWork W1966775726 @default.
• W1996959454 hasRelatedWork W1979139803 @default.
• W1996959454 hasRelatedWork W2030889776 @default.
• W1996959454 hasRelatedWork W2037631372 @default.
• W1996959454 hasRelatedWork W2040058909 @default.
• W1996959454 hasRelatedWork W2132898409 @default.

• next