Suppressed hindlimb perfusion in Rac2 -/-and Nox2 -/- mice does not result from impaired collateral growth

Matthew R. Distasi, Jamie Case, Matthew A. Ziegler, Mary C. Dinauer, Mervin Yoder, Laura Haneline, Michael Dalsing, Steven Miller, Carlos A. Labarrere, Michael Murphy, David Ingram, Joseph L. Unthank

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22 Citations (Scopus)

Abstract

While tissue perfusion and angiogenesis subsequent to acute femoral artery occlusion are suppressed in NADPH oxidase 2 (Nox2)-null (Nox2 -/-) mice, studies have not established the role of Nox2 in collateral artery enlargement. Rac2 is a small GTPase that binds Nox2 and activates Nox2-based NAD(P)H oxidase but, unlike Nox2, is primarily restricted to bone marrow-derived cells. In this study, we used Rac2- null (Rac2 -/-) and Nox2 -/- mice with a novel method of identifying primary hindlimb collaterals to investigate the hypothesis that collateral growth requires these molecules. When initial experiments performed with femoral ligation demonstrated similar perfusion and collateral growth in Rac2 -/- and wild-type C57BL/6J (BL6) mice, subsequent experiments were performed with a more severe ischemia model, femoral artery excision. After femoral excision, tissue perfusion was suppressed in Rac2 -/- mice relative to BL6 mice. Histological assessment of ischemic injury including necrotic and regenerated muscle fibers and lipid and collagen deposition demonstrated greater injury in Rac2 -/- mice. The diameters of primary collaterals identified during Microfil injection with intravital microscopy were enlarged to a similar extent in BL6 and Rac2 -/- mice. Intimal cells in collateral cross sections were increased in number in both strains and were CD31 positive and CD45 negative. Circulating leukocytes and CD11b + cells were increased more in Rac2 -/- than BL6 animals. Experiments performed in Nox2 -/- mice to verify that the unexpected results related to collateral growth were not unique to Rac2 -/- mice gave equivalent results. The data demonstrate that, subsequent to acute femoral artery excision, perfusion recovery is impaired in Rac2 -/- and Nox2 -/- mice but that collateral luminal expansion and intimal cell recruitment proliferation are normal. These novel results indicate that collateral luminal expansion and intimal cell recruitment proliferation are not mediated by Rac2 and Nox2.

Original languageEnglish
JournalAmerican Journal of Physiology - Heart and Circulatory Physiology
Volume296
Issue number3
DOIs
StatePublished - Mar 2009

Fingerprint

NADPH Oxidase
Hindlimb
Perfusion
Tunica Intima
Femoral Artery
Growth
Thigh
Cell Proliferation
Silicone Elastomers
Monomeric GTP-Binding Proteins
Wounds and Injuries
Bone Marrow Cells
Ligation
Mouse Cybb protein
Leukocytes
Collagen
Ischemia
Arteries
Lipids
Muscles

Keywords

  • Arteriogenesis
  • Hindlimb ischemia
  • Nadph oxidase 2
  • Necrosis
  • Regeneration

ASJC Scopus subject areas

  • Physiology
  • Physiology (medical)
  • Cardiology and Cardiovascular Medicine

Cite this

@article{c0a5bcc89227435997a9b94d5554ecd7,
title = "Suppressed hindlimb perfusion in Rac2 -/-and Nox2 -/- mice does not result from impaired collateral growth",
abstract = "While tissue perfusion and angiogenesis subsequent to acute femoral artery occlusion are suppressed in NADPH oxidase 2 (Nox2)-null (Nox2 -/-) mice, studies have not established the role of Nox2 in collateral artery enlargement. Rac2 is a small GTPase that binds Nox2 and activates Nox2-based NAD(P)H oxidase but, unlike Nox2, is primarily restricted to bone marrow-derived cells. In this study, we used Rac2- null (Rac2 -/-) and Nox2 -/- mice with a novel method of identifying primary hindlimb collaterals to investigate the hypothesis that collateral growth requires these molecules. When initial experiments performed with femoral ligation demonstrated similar perfusion and collateral growth in Rac2 -/- and wild-type C57BL/6J (BL6) mice, subsequent experiments were performed with a more severe ischemia model, femoral artery excision. After femoral excision, tissue perfusion was suppressed in Rac2 -/- mice relative to BL6 mice. Histological assessment of ischemic injury including necrotic and regenerated muscle fibers and lipid and collagen deposition demonstrated greater injury in Rac2 -/- mice. The diameters of primary collaterals identified during Microfil injection with intravital microscopy were enlarged to a similar extent in BL6 and Rac2 -/- mice. Intimal cells in collateral cross sections were increased in number in both strains and were CD31 positive and CD45 negative. Circulating leukocytes and CD11b + cells were increased more in Rac2 -/- than BL6 animals. Experiments performed in Nox2 -/- mice to verify that the unexpected results related to collateral growth were not unique to Rac2 -/- mice gave equivalent results. The data demonstrate that, subsequent to acute femoral artery excision, perfusion recovery is impaired in Rac2 -/- and Nox2 -/- mice but that collateral luminal expansion and intimal cell recruitment proliferation are normal. These novel results indicate that collateral luminal expansion and intimal cell recruitment proliferation are not mediated by Rac2 and Nox2.",
keywords = "Arteriogenesis, Hindlimb ischemia, Nadph oxidase 2, Necrosis, Regeneration",
author = "Distasi, {Matthew R.} and Jamie Case and Ziegler, {Matthew A.} and Dinauer, {Mary C.} and Mervin Yoder and Laura Haneline and Michael Dalsing and Steven Miller and Labarrere, {Carlos A.} and Michael Murphy and David Ingram and Unthank, {Joseph L.}",
year = "2009",
month = "3",
doi = "10.1152/ajpheart.00772.2008",
language = "English",
volume = "296",
journal = "American Journal of Physiology",
issn = "0193-1857",
publisher = "American Physiological Society",
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TY - JOUR

T1 - Suppressed hindlimb perfusion in Rac2 -/-and Nox2 -/- mice does not result from impaired collateral growth

AU - Distasi, Matthew R.

AU - Case, Jamie

AU - Ziegler, Matthew A.

AU - Dinauer, Mary C.

AU - Yoder, Mervin

AU - Haneline, Laura

AU - Dalsing, Michael

AU - Miller, Steven

AU - Labarrere, Carlos A.

AU - Murphy, Michael

AU - Ingram, David

AU - Unthank, Joseph L.

PY - 2009/3

Y1 - 2009/3

N2 - While tissue perfusion and angiogenesis subsequent to acute femoral artery occlusion are suppressed in NADPH oxidase 2 (Nox2)-null (Nox2 -/-) mice, studies have not established the role of Nox2 in collateral artery enlargement. Rac2 is a small GTPase that binds Nox2 and activates Nox2-based NAD(P)H oxidase but, unlike Nox2, is primarily restricted to bone marrow-derived cells. In this study, we used Rac2- null (Rac2 -/-) and Nox2 -/- mice with a novel method of identifying primary hindlimb collaterals to investigate the hypothesis that collateral growth requires these molecules. When initial experiments performed with femoral ligation demonstrated similar perfusion and collateral growth in Rac2 -/- and wild-type C57BL/6J (BL6) mice, subsequent experiments were performed with a more severe ischemia model, femoral artery excision. After femoral excision, tissue perfusion was suppressed in Rac2 -/- mice relative to BL6 mice. Histological assessment of ischemic injury including necrotic and regenerated muscle fibers and lipid and collagen deposition demonstrated greater injury in Rac2 -/- mice. The diameters of primary collaterals identified during Microfil injection with intravital microscopy were enlarged to a similar extent in BL6 and Rac2 -/- mice. Intimal cells in collateral cross sections were increased in number in both strains and were CD31 positive and CD45 negative. Circulating leukocytes and CD11b + cells were increased more in Rac2 -/- than BL6 animals. Experiments performed in Nox2 -/- mice to verify that the unexpected results related to collateral growth were not unique to Rac2 -/- mice gave equivalent results. The data demonstrate that, subsequent to acute femoral artery excision, perfusion recovery is impaired in Rac2 -/- and Nox2 -/- mice but that collateral luminal expansion and intimal cell recruitment proliferation are normal. These novel results indicate that collateral luminal expansion and intimal cell recruitment proliferation are not mediated by Rac2 and Nox2.

AB - While tissue perfusion and angiogenesis subsequent to acute femoral artery occlusion are suppressed in NADPH oxidase 2 (Nox2)-null (Nox2 -/-) mice, studies have not established the role of Nox2 in collateral artery enlargement. Rac2 is a small GTPase that binds Nox2 and activates Nox2-based NAD(P)H oxidase but, unlike Nox2, is primarily restricted to bone marrow-derived cells. In this study, we used Rac2- null (Rac2 -/-) and Nox2 -/- mice with a novel method of identifying primary hindlimb collaterals to investigate the hypothesis that collateral growth requires these molecules. When initial experiments performed with femoral ligation demonstrated similar perfusion and collateral growth in Rac2 -/- and wild-type C57BL/6J (BL6) mice, subsequent experiments were performed with a more severe ischemia model, femoral artery excision. After femoral excision, tissue perfusion was suppressed in Rac2 -/- mice relative to BL6 mice. Histological assessment of ischemic injury including necrotic and regenerated muscle fibers and lipid and collagen deposition demonstrated greater injury in Rac2 -/- mice. The diameters of primary collaterals identified during Microfil injection with intravital microscopy were enlarged to a similar extent in BL6 and Rac2 -/- mice. Intimal cells in collateral cross sections were increased in number in both strains and were CD31 positive and CD45 negative. Circulating leukocytes and CD11b + cells were increased more in Rac2 -/- than BL6 animals. Experiments performed in Nox2 -/- mice to verify that the unexpected results related to collateral growth were not unique to Rac2 -/- mice gave equivalent results. The data demonstrate that, subsequent to acute femoral artery excision, perfusion recovery is impaired in Rac2 -/- and Nox2 -/- mice but that collateral luminal expansion and intimal cell recruitment proliferation are normal. These novel results indicate that collateral luminal expansion and intimal cell recruitment proliferation are not mediated by Rac2 and Nox2.

KW - Arteriogenesis

KW - Hindlimb ischemia

KW - Nadph oxidase 2

KW - Necrosis

KW - Regeneration

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U2 - 10.1152/ajpheart.00772.2008

DO - 10.1152/ajpheart.00772.2008

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JO - American Journal of Physiology

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