Long Term Response to Circulating Angiogenic Cells, Unstimulated or Atherosclerotic Pre-Conditioned, in Critical Limb Ischemic Mice.

Lucía Beltrán-Camacho,Almudena González-Rovira,Mª Jesús Extremera-García,Manuel Rodriguez-Piñero,Marta Rojas-Torres,Esther Doiz,Martin R Larsen,Margarita Jiménez-Palomares,Ismael Sanchez-Gomar,Mª Carmen Duran-Ruiz,Jose Angel Alonso-Piñero,Antonio Rosal-Vela,Rosario Conejero,Sara Eslava-Alcon

doi:10.3390/biomedicines9091147

Abstract

Critical limb ischemia (CLI), the most severe form of peripheral artery disease, results from the blockade of peripheral vessels, usually correlated to atherosclerosis. Currently, endovascular and surgical revascularization strategies cannot be applied to all patients due to related comorbidities, and even so, most patients require re-intervention or amputation within a year. Circulating angiogenic cells (CACs) constitute a good alternative as CLI cell therapy due to their vascular regenerative potential, although the mechanisms of action of these cells, as well as their response to pathological conditions, remain unclear. Previously, we have shown that CACs enhance angiogenesis/arteriogenesis from the first days of administration in CLI mice. Also, the incubation ex vivo of these cells with factors secreted by atherosclerotic plaques promotes their activation and mobilization. Herein, we have evaluated the long-term effect of CACs administration in CLI mice, whether pre-stimulated or not with atherosclerotic factors. Remarkably, mice receiving CACs and moreover, pre-stimulated CACs, presented the highest blood flow recovery, lower progression of ischemic symptoms, and decrease of immune cells recruitment. In addition, many proteins potentially involved, like CD44 or matrix metalloproteinase 9 (MMP9), up-regulated in response to ischemia and decreased after CACs administration, were identified by a quantitative proteomics approach. Overall, our data suggest that pre-stimulation of CACs with atherosclerotic factors might potentiate the regenerative properties of these cells in vivo.

Highlights

This article is an open access articlePeripheral artery disease (PAD) is an under-estimated and under-diagnosed cardiovascular disease (CVD) that is asymptomatic at initial stages [1] and affects more than 202 million people worldwide, approximately 10–15% of the adult population [2]
Only mice receiving Circulating angiogenic cells (CACs) stimulated with the AP secretome from patient-3 (SF3) showed significant perfusion recovery compared to untreated SC (p-value: 0.0052) (Figure 1B), while mice treated with CACs pre-incubated with the patient-1 AP secretome (SF1) had lower blood flow ratios than SF2 and SF3, but similar values to SE mice, without stimulation
Based on the changes seen in the long term in CACs-treated mice, their effect on the first days seems crucial, enhancing reperfusion while modulating the participation of immune cells to assist in tissue restoration without producing an exacerbated inflammatory response, reducing cell death and, for instance, the progression of the ischemic damage

Summary

Introduction

This article is an open access articlePeripheral artery disease (PAD) is an under-estimated and under-diagnosed cardiovascular disease (CVD) that is asymptomatic at initial stages [1] and affects more than 202 million people worldwide, approximately 10–15% of the adult population [2]. Two different subpopulations of EPCs have been described [9,10,11,12,13]: early EPCs, called circulating angiogenic cells (CACs) or myeloid angiogenic cells, and late outgrowth EPCs or endothelial colony-forming cells (ECFCs). Both sets of cells have been tested to promote revascularization in ischemic diseases such as myocardial infarction or CLI [14,15,16,17,18,19,20]. CACs release factors that appear to promote ECFCs tubule formation in vitro [13,24]

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