Shock wave treatment after hindlimb ischaemia results in increased perfusion and M2 macrophage presence.
Shock wave therapy (SWT) has been shown to induce angiogenesis in ischaemic muscle. However, the mechanism of action remains unknown. Macrophages are crucial for angiogenic responses after ischaemic injury. The M2 macrophage subset enables tissue repair and induces angiogenesis. It was hypothesized that the angiogenic effects of SWT are at least partly caused by enhanced macrophage recruitment. C57BL/6 mice were subjected to hind limb ischaemia with subsequent SWT or sham treatment. Muscles were analysed via immunofluorescence staining, reverse-transcription polymerase chain reaction and western blot. Gene expression and proteins involved in macrophage recruitment were analysed and tissue sections were stained for macrophages, including subsets, capillaries and arterioles. Laser Doppler perfusion imaging was performed to assess functional outcome. Treated muscles showed increased expression of the pivotal macrophage recruiting factor monocyte chemotactic protein 1 (MCP-1). Higher levels of macrophage marker CD14 were found. Increased numbers of macrophages after SWT could be confirmed by immunofluorescence staining. The expression of the M2 polarization promoting chemokine interleukin 13 was significantly elevated in the treatment group. Elevated mRNA expression of the M2 scavenger receptor CD163 was found after SWT. Immunofluorescence staining confirmed increased numbers of M2 macrophages after treatment. It was found that SWT resulted in higher number of capillaries and arterioles. Assessment of functional outcome revealed significantly improved limb perfusion in treated animals. Shock wave therapy causes increased macrophage recruitment and enhanced polarization towards reparative M2 macrophages in ischaemic muscle resulting in angiogenesis and improved limb perfusion and therefore represents a promising new treatment option for the treatment of ischaemic heart disease. Copyright © 2016 John Wiley & Sons, Ltd.
University Hospital for Cardiac Surgery, Innsbruck Medical University, Austria.
Can
C
Tepeköylü
University Hospital for Cardiac Surgery, Innsbruck Medical University, Austria.
Daniela
D
Lobenwein
Department of Urology and Paediatric Urology, Philipps-University Marburg, Germany.
Anja
A
Urbschat
University Hospital for Cardiac Surgery, Innsbruck Medical University, Austria.
Michael
M
Graber
Division of Clinical and Functional Anatomy, Department of Anatomy, Histology and Embryology, Innsbruck Medical University, Austria.
Elisabeth Judith
EJ
Pechriggl
Division of Clinical and Functional Anatomy, Department of Anatomy, Histology and Embryology, Innsbruck Medical University, Austria.
Helga
H
Fritsch
Department of Anaesthesiology and Operative Intensive Care Medicine, Kepler University Hospital Linz, Austria.
Patrick
P
Paulus
University Hospital for Cardiac Surgery, Innsbruck Medical University, Austria.
Michael
M
Grimm
University Hospital for Cardiac Surgery, Innsbruck Medical University, Austria.
Johannes
J
Holfeld
D000818:Animals; D001160:Arterioles / Q000473:pathology; D002196:Capillaries / Q000473:pathology; D002452:Cell Count; D016764:Cell Polarity; D019220:High-Energy Shock Waves; D006614:Hindlimb / Q000098:blood supply*; D007511:Ischemia / Q000473:pathology / Q000628:therapy*; D008264:Macrophages / Q000378:metabolism*; D008297:Male; D008810:Mice, Inbred C57BL; D009132:Muscles / Q000098:blood supply / Q000473:pathology; D010477:Perfusion
angiogenesis; ischaemic heart disease; macrophages; shock wave therapy