The Role of miR-126 in Critical Limb Ischemia Treatment Using Adipose-Derived Stem Cell Therapeutic Factor Concentrate and Extracellular Matrix Microparticles

Abstract

BackgroundParacrine factors secreted by adipose-derived stem cells can be captured, fractionated, and concentrated to produce therapeutic factor concentrate (TFC). The present study examined whether TFC effects could be enhanced by combining TFC with a biological matrix to provide sustained release of factors in the target region.Material/MethodsUnilateral hind limb ischemia was induced in rabbits. Ischemic limbs were injected with either placebo control, TFC, micronized small intestinal submucosa tissue (SIS), or TFC absorbed to SIS. Blood flow in both limbs was assessed with laser Doppler perfusion imaging. Tissues harvested at Day 48 were assessed immunohistochemically for vessel density; in situ hybridization and quantitative real-time PCR were employed to determine miR-126 expression.ResultsLDP ratios were significantly elevated, compared to placebo control, on day 28 in all treatment groups (p=0.0816, p=0.0543, p=0.0639, for groups 2–4, respectively) and on day 36 in the TFC group (p=0.0866). This effect correlated with capillary density in the SIS and TFC+SIS groups (p=0.0093 and p=0.0054, respectively, compared to placebo). A correlation was observed between miR-126 levels and LDP levels at 48 days in SIS and TFC+SIS groups.ConclusionsA single bolus administration of TFC and SIS had early, transient effects on reperfusion and promotion of ischemia repair. The effects were not additive. We also discovered that TFC modulated miR-126 levels that were expressed in cell types other than endothelial cells. These data suggested that TFC, alone or in combination with SIS, may be a potent therapy for patients with CLI that are at risk of amputation.

MicroRNAs in peripheral artery disease: potential biomarkers and pathophysiological mechanisms

“…miR-126 in the media was identified as a possible mechanism for the vascular regeneration, as levels of the microRNA were increased in gastrocnemius tissue samples of the rabbits, and in situ hybridization technique showed miR-126 being expressed in the vascular endothelium, smooth muscle cells of the arterioles, fibrous scars, and in the sarcoplasm of some muscle fibers. 91 miRNAs may also play a role in the process of pathological fibrosis associated with PAD via modulation of the TGF-β pathway. For example, miR-29 overexpression in myoblasts inhibits fibrogenic differentiation and suppresses collagen synthesis.…”

“…miR-126 in the media was identified as a possible mechanism for the vascular regeneration, as levels of the microRNA were increased in gastrocnemius tissue samples of the rabbits, and in situ hybridization technique showed miR-126 being expressed in the vascular endothelium, smooth muscle cells of the arterioles, fibrous scars, and in the sarcoplasm of some muscle fibers. 91…”

Current Status of Cell-Based Therapy in Patients with Critical Limb Ischemia

“…The three predominant paracrine actions of adipose stem cell-secreted factors are trophic support of survival and repair of cells in diseased or injured tissues (VEGF, HGF), modulation of the immune system (IL-10, PGE2), and recruitment of endogenous stem and progenitor cells (GM-CSF, SDF-1). Moreover, these factors have the potential to work in concert to affect physiological improvements in diseased and injured tissues [59].…”

Upregulated microRNA‐126 induces apoptosis of dental pulp stem cell via mediating PTEN‐regulated Akt activation

“…MiR‐126, frequently being downregulated in human tumors, has been demonstrated to possess fundamental roles in various cellular processes, especially in the modulation of proliferation and differentiation 13‐17 . MiR‐126 was also involved in the basal function of adipose tissue stem cell and mesenchymal stem cell 18‐20 . However, the mechanism of miR‐126 in regulating the function of human DPSCs remain needs to be further investigated.…”