Macrophages mobilized by the overexpression of the macrophage-colony stimulating factor promote efficient recovery of the ischemic muscle functionality

Author(s)

Gallo, Camila Congentino ; Honda, Tamisa Seeko Bandeira ; Alves, Patricia Terra ; Han, Sang Won

• Document type: Journal article
• Source: Life Sciences; v. 317, p. 11-pg., 2023-02-10.

Abstract

Aims: Narrowing or occlusion of arteries that supply the limbs can evolve to critical limb ischemia. M-CSF promotes proliferation, differentiation and survival of monocytes and macrophages, and polarization of mac-rophages to M2-subtype, which are essential elements for vessel formation and tissue repair. Based on these properties of M-CSF, we hypothesize that transfection of M-CSF into ischemic limbs may promote vessel for-mation and repair of ischemic limbs. Main methods: Hindlimb ischemia was surgically induced in 10-12 weeks old Balb/c and gene therapy was performed with intramuscular application of either uP-MCSF or uP plasmids (100 mu g). Macrophage and mono-cyte subpopulations were assessed by flow cytometry and blood flow was monitored by Laser Doppler Perfusion Imaging (LDPI). Thirty days after transfection, we assessed gastrocnemius mass and muscle force, subsequently collecting the muscle for histology. Key findings: We successfully developed the uP-MCSF plasmid, which increases M-CSF expression in the muscle transiently. Thirty days after uP-MCSF gene therapy in ischemic muscles, the treated group presented: improved muscle force, reduced fibrosis and increased arteriogenesis, although LDPI analysis did not show any significant difference in blood flow among groups. Noteworthy, we observed a temporary increase in MHCIIhighCD206high macrophages after uP-MCSF transfection. Significance: M-CSF gene therapy improved ischemic muscle functionality by promoting arteriogenesis and decreasing fibrosis, likely through increased MHCIIhighCD206high macrophages and not via classically known M2-macrophages. (AU)

• FAPESP's process: 15/20206-8 - Modulation of monocytes, macrophages and pericytes by the colony stimulating factor genes to treat murine limb ischemia
• Grantee: Sang Won Han
• Support Opportunities: Research Projects - Thematic Grants