Syndecan-4 proteoliposomes enhance fibroblast growth factor-2 (FGF-2)–induced proliferation, migration, and neovascularization of ischemic muscle

Abstract

Ischemia of the myocardium and lower limbs is a common consequence of arterial disease and a major source of morbidity and mortality in modernized countries. Inducing neovascularization for the treatment of ischemia is an appealing therapeutic strategy for patients for whom traditional treatment modalities cannot be performed or are ineffective. In the past, the stimulation of blood vessel growth was pursued using direct delivery of growth factors, angiogenic gene therapy, or cellular therapy. Although therapeutic angiogenesis holds great promise for treating patients with ischemia, current methods have not found success in clinical trials. Fibroblast growth factor-2 (FGF-2) was one of the first growth factors to be tested for use in therapeutic angiogenesis. Here, we present a method for improving the biological activity of FGF-2 by codelivering the growth factor with a liposomally embedded coreceptor, syndecan-4. This technique was shown to increase FGF-2 cellular signaling, uptake, and nuclear localization in comparison with FGF-2 alone. Delivery of syndecan-4 proteoliposomes also increased endothelial proliferation, migration, and angiogenic tube formation in response to FGF-2. Using an animal model of limb ischemia, syndecan-4 proteoliposomes markedly improved the neovascularization following femoral artery ligation and recovery of perfusion of the ischemic limb. Taken together, these results support liposomal delivery of syndecan-4 as an effective means to improving the potential of using growth factors to achieve therapeutic neovascularization of ischemic tissue.

Syndesome Therapeutics for Enhancing Diabetic Wound Healing

“…This hypothesis is consistent with our previous finding that free syndecan-4 is not as effective in enhancing FGF-2 uptake, signaling and angiogenesis. [16] It would also be consistent with our finding of increased recycling of FGF-2 through the slow (Rab11) and fast (Rab4) mechanisms that we observed in our studies. This increased recycling may be the result of FGF-2 bound syndecan-4 being trafficked back to the surface after being internalized through the syndesome construct.…”

“…[33] Our previous work has shown that delivery of syndecan-4 in a proteoliposome was more potent in inducing cell proliferation/migration, activation of ERK1/2 signaling pathway, in vitro endothelial tube formation, nuclear trafficking of growth factors and angiogenesis in comparison to the free syndecan-4 protein. [16] In our studies showed increased migration in keratinocytes and decreased invasion activity when the cells were treated with exogenous syndecan-4 protein in a proteoliposome. This would suggest that the developed treatments would be able to synergistically enhance cell therapies, including those delivered from electrospun materials.…”

“…[15] FGF-2 (Peprotech) was conjugated with Alexa Fluor 594 (Life Technologies) using the heparin column that binds the active site of FGF-2 preserving its biological activity. [10, 16] HEK293Ta cells plated on 8-well glass slides (ibidi) at 10000cells/well and were transfected with the above-mentioned plasmids using DNA HTS jetPEI transfection reagent (Polyplus transfection™) using standard protocol. Twenty four hours post transfection, the cells were treated with AF594 tagged FGF-2 (1 µl) and/or syndesomes (1 µl).…”

Syndecan‐4 Enhances Therapeutic Angiogenesis after Hind Limb Ischemia in Mice with Type 2 Diabetes

“…The artery was ligated with two 6-0 silk sutures as described in our previous study. [14] Alginate beads were then applied directly to the region surrounding the femoral artery and the incision site was closed using surgical staples. The feet of the mice were imaged at 1, 3, 5, 7 and 14 days using laser speckle contrast imaging as described below.…”

Biomaterials and Nanotherapeutics for Enhancing Skin Wound Healing

“…One method to overcome this resistance is to deliver co-receptors in a proteoliposome along with the growth factors. This was tested in a diabetic mouse model and showed improved diabetic wound healing (Das et al, 2016a,c) and enhanced ischemic revascularization (Jang et al, 2012; Das et al, 2014, 2016b; Monteforte et al, 2016)(Figure 5). There are various other lipid NPs, which have shown promise for treating peripheral vascular disease and critical limb ischemia, reviewed elsewhere (Tu et al, 2015).…”