title: Bone marrow alterations and lower endothelial progenitor cell numbers in critical limb ischemia patients.
abstract: BACKGROUND
  Critical limb ischemia (CLI) is characterized by lower extremity artery obstruction and a largely unexplained impaired ischemic neovascularization response. Bone marrow (BM) derived endothelial progenitor cells (EPC) contribute to neovascularization. We hypothesize that reduced levels and function of circulating progenitor cells and alterations in the BM contribute to impaired neovascularization in CLI.
  
  
  METHODS
  Levels of primitive (CD34(+) and CD133(+)) progenitors and CD34(+)KDR(+) EPC were analyzed using flow cytometry in blood and BM from 101 CLI patients in the JUVENTAS-trial (NCT00371371) and healthy controls. Blood levels of markers for endothelial injury (sE-selectin, sICAM-1, sVCAM-1, and thrombomodulin), and progenitor cell mobilizing and inflammatory factors were assessed by conventional and multiplex ELISA. BM levels and activity of the EPC mobilizing protease MMP-9 were assessed by ELISA and zymography. Circulating angiogenic cells (CAC) were cultured and their paracrine function was assessed.
  
  
  RESULTS
  Endothelial injury markers were higher in CLI (P<0.01). CLI patients had higher levels of VEGF, SDF-1α, SCF, G-CSF (P<0.05) and of IL-6, IL-8 and IP-10 (P<0.05). Circulating EPC and BM CD34(+) cells (P<0.05), lymphocytic expression of CXCR4 and CD26 in BM (P<0.05), and BM levels and activity of MMP-9 (P<0.01) were lower in CLI. Multivariate regression analysis showed an inverse association between IL-6 and BM CD34(+) cell levels (P = 0.007). CAC from CLI patients had reduced paracrine function (P<0.0001).
  
  
  CONCLUSIONS
  CLI patients have reduced levels of circulating EPC, despite profound endothelial injury and an EPC mobilizing response. Moreover, CLI patients have lower BM CD34(+)-cell levels, which were inversely associated with the inflammatory marker IL-6, and lower BM MMP-9 levels and activity. The results of this study suggest that inflammation-induced BM exhaustion and a disturbed progenitor cell mobilization response due to reduced levels and activity of MMP-9 in the BM and alterations in the SDF-1α/CXCR4 interaction contribute to the attenuated neovascularization in CLI patients.
authors: Department of Nephrology & Hypertension, University Medical Center Utrecht, Utrecht, The Netherlands.
authors: Martin
authors: M
authors: Teraa
authors: Ralf W
authors: RW
authors: Sprengers
authors: Peter E
authors: PE
authors: Westerweel
authors: Hendrik
authors: H
authors: Gremmels
authors: Marie-José T H
authors: MJ
authors: Goumans
authors: Tom
authors: T
authors: Teerlink
authors: Frans L
authors: FL
authors: Moll
authors: Marianne C
authors: MC
authors: Verhaar
mesh_terms: D000368:Aged; D018952:Antigens, CD34 / Q000378:metabolism; D001120:Arginine / Q000097:blood; D015415:Biomarkers / Q000097:blood; D001853:Bone Marrow / Q000473:pathology*; D016022:Case-Control Studies; D018819:Dipeptidyl Peptidase 4 / Q000378:metabolism; D042783:Endothelial Cells / Q000378:metabolism*; D005121:Extremities / Q000098:blood supply*; D005260:Female; D006412:Hematopoietic Stem Cells / Q000378:metabolism; D006801:Humans; D007249:Inflammation / Q000378:metabolism; D007511:Ischemia / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D019899:Paracrine Communication; D019718:Receptors, CXCR4 / Q000378:metabolism; D013234:Stem Cells / Q000378:metabolism*
chemical_list: D018952:Antigens, CD34; D015415:Biomarkers; D019718:Receptors, CXCR4; D001120:Arginine; D018819:Dipeptidyl Peptidase 4
references: J Am Coll Cardiol. 2005 May 3;45(9):1449-57
references: 15862417
references: Atherosclerosis. 2011 May;216(1):244-7
references: 21334625
references: Blood. 2000 Feb 1;95(3):952-8
references: 10648408
references: J Am Coll Cardiol. 2007 Jun 19;49(24):2341-9
references: 17572250
references: Arterioscler Thromb Vasc Biol. 2006 Sep;26(9):2140-6
references: 16857948
references: Ann Rheum Dis. 2007 Jul;66(7):865-70
references: 17329307
references: Atherosclerosis. 2008 Dec;201(2):236-47
references: 18599065
references: J Vasc Surg. 2010 Jun;51(6):1564-8
references: 20488328
references: Br J Surg. 2008 Feb;95(2):244-51
references: 17702088
references: Cancer Res. 2012 Jun 1;72(11):2705-13
references: 22467173
references: Heart Vessels. 2012 Jan;27(1):38-45
references: 21384270
references: JAMA. 2007 Mar 21;297(11):1197-206
references: 17374814
references: Nat Med. 2003 Nov;9(11):1370-6
references: 14556003
references: FEBS Lett. 2001 Jul 13;501(1):37-41
references: 11457452
references: Eur J Vasc Endovasc Surg. 2007;33 Suppl 1:S1-75
references: 17140820
references: Circ Res. 2007 Mar 30;100(6):904-13
references: 17322177
references: Int Heart J. 2010 Jan;51(1):1-6
references: 20145343
references: Cardiovasc Diabetol. 2011 Oct 08;10:88
references: 21981808
references: Science. 1997 Feb 14;275(5302):964-7
references: 9020076
references: J Atheroscler Thromb. 2012;19(2):149-58
references: 22123215
references: Cell Transplant. 2010;19(11):1425-37
references: 20587143
references: Circ Res. 2001 Jul 6;89(1):E1-7
references: 11440984
references: Cell. 2002 May 31;109(5):625-37
references: 12062105
references: Circulation. 2001 Jun 12;103(23):2776-9
references: 11401930
references: Respir Med. 2008 Jul;102(7):1073-9
references: 18394873
references: Blood. 2003 Jun 15;101(12):4680-6
references: 12576320
references: Arterioscler Thromb Vasc Biol. 2007 Nov;27(11):2310-8
references: 17717295
references: Arterioscler Thromb Vasc Biol. 2009 Aug;29(8):1179-84
references: 19461050
references: J Orthop Res. 2007 Jan;25(1):44-50
references: 17001704
references: Circ Res. 2011 Sep 16;109(7):724-8
references: 21835908
references: Science. 2002 Aug 16;297(5584):1186-90
references: 12183632
references: Anal Biochem. 2002 Apr 15;303(2):131-7
references: 11950212
references: Diabet Med. 2009 Feb;26(2):134-41
references: 19236615
references: Anal Biochem. 2006 Jun 15;353(2):287-9
references: 16603118
references: Vasc Med. 2001;6(2):87-96
references: 11530970
references: Diabetologia. 2006 Dec;49(12):3075-84
references: 17072586
references: J Rheumatol. 2008 Mar;35(3):380-6
references: 18260177
references: Circulation. 2007 Oct 9;116(15):1671-82
references: 17909106
references: Circulation. 2006 Oct 3;114(14):1522-30
references: 17000905
references: Mol Cancer Res. 2008 Apr;6(4):525-34
references: 18403633
references: Arterioscler Thromb Vasc Biol. 2006 Feb;26(2):257-66
references: 16322535
references: Ann Rheum Dis. 2007 Oct;66(10):1284-8
references: 17293363
references: Am J Physiol Regul Integr Comp Physiol. 2008 Mar;294(3):R811-8
references: 18094068
references: Circulation. 2004 Apr 6;109(13):1615-22
references: 15037527
references: Atherosclerosis. 2008 Apr;197(2):496-503
references: 18249408
references: Int J Cardiol. 2010 Mar 4;139(2):134-41
references: 19008002
references: Circulation. 2003 Mar 4;107(8):1164-9
references: 12615796
references: Cell Transplant. 2009;18(9):1003-12
references: 19650968
references: Thromb Haemost. 2007 May;97(5):714-21
references: 17479181
references: JAMA. 2001 Sep 19;286(11):1317-24
references: 11560536
references: J Am Coll Cardiol. 2008 Feb 12;51(6):660-8
references: 18261686
references: Nephrol Dial Transplant. 2010 Jun;25(6):1875-82
references: 20083473