Local delivery of polarized macrophages improves reperfusion recovery in a mouse hind limb ischemia model

PLoS One. 2013 Jul 24;8(7):e68811. doi: 10.1371/journal.pone.0068811. Print 2013.

Abstract

Aims: Enhancement of collateral development in coronary or peripheral artery disease is a therapeutic target, but it has proven difficult to achieve. Macrophages are key players in collateral remodeling, yet the effect of different macrophage subsets on arteriogenesis has not been investigated.

Methods and results: Murine macrophages were cultured from bone marrow and polarized into M1 (IFNγ), M2a (IL-4) or M2c (IL-10) subsets. C57BL/6 mice underwent femoral artery ligation followed by intramuscular injection of macrophage subsets. Using eGFP expressing macrophages, cells could be detected at least 6 days after ligation and were located in the perivascular space of collateral vessels. After 14 days, perfusion ratio was increased in animals treated with M1 as well as M2a and M2c macrophages compared to control. Depletion of circulating monocytes by clodronate liposome injections did not hamper reperfusion recovery, however, treatment with exogenous polarized macrophages improved perfusion ratio after 14 days again. We used IL10R(fl/fl)/LysMCre(+) mice to study the effect of inhibition of endogenous polarization towards specifically M2c macrophages on arteriogenesis. Deletion of the IL10-receptor (IL10R) in the myeloid lineage did not affect reperfusion recovery, yet the pro-arteriogenic effect of exogenously injected M2c macrophages was still present.

Conclusions: Local injection of polarized macrophages promotes reperfusion recovery after femoral artery ligation and is not influenced by depletion of circulatory monocytes. Preventing endogenous M2c polarization did not affect reperfusion recovery suggesting that M2c's are not required for collateralization, but are sufficient to induce collateral formation upon exogenous administration. This is the first study using local injection of macrophage subsets showing the pro-arteriogenic effect of polarized macrophages.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cells, Cultured
  • Female
  • Femur / cytology
  • Hindlimb / pathology*
  • Ischemia / metabolism
  • Ischemia / therapy*
  • Macrophages / cytology*
  • Macrophages / metabolism
  • Macrophages / physiology
  • Mice
  • Mice, Inbred C57BL
  • Reperfusion Injury / metabolism
  • Reperfusion Injury / therapy*
  • Tibia / cytology

Grant support

This work was supported by the Netherlands Heart Foundation (Dr. E. Dekker post-doctoral fellow grant [grant numbers 2007T034, 2012T079] to Dr. Donners; Dr. E. Dekker Established Investigator grant [grant number 2007T067] and the Netherlands Organisation for Scientific Research (NWO)-VIDI grant [grant number 917.066.329] to Dr. de Winther). Dr Post is supported by grants from BMM (PENT, iValve) and CTMM/Netherland Heart Foundation (EMINENCE): These research programs of the BioMedical Materials institute and the Center for Translational and Molecular Medicine are co-funded by the Dutch Ministry of economic affairs Agriculture and Innovation. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.