Treatment Of Severe Limb Ischemia Research Articles

Abstract 10174: Intravenous Muse Cell Transplantation Enhances Angiogenesis and Reduces Muscle Fibrosis in a Mouse Hindlimb Ischemia Model

Introduction: Multilineage-differentiating stress enduring (Muse) cells, a unique subpopulation of mesenchymal stem cells (MSCs), have been proposed as a promising cell source for regenerative medicine. However, the therapeutic potential of the Muse cells in ischemic limb disease remains unclear. In this study, we aimed to investigate therapeutic potential of Muse cell transplantation for the treatment of severe limb ischemia. Methods and Results: Muse cells isolated from human MSCs, non-Muse MSCs, or mouse bone marrow-derived mononuclear cells (BM-MNCs) were administered intravenously or intramuscularly to a mouse model of hindlimb ischemia (HLI). When the same number of cells were administered, blood flow recovery of the ischemic limb was significantly enhanced in the mice administered with Muse cells over 2 weeks compared to the others. Intravenous Muse cell administration resulted in comparable blood flow recovery to intramuscular Muse cell administration. Immunohistochemistry analysis revealed that intravenous Muse cell administration increased microvascular density and ameliorated interstitial fibrosis in the ischemic limb. We detected mCherry-labeled Muse cells expressing CD31 and human genomic DNA in the ischemic limb 1 week after the intravenous Muse cell administration. Muse cells produced higher VEGF compared to non-Muse MSCs, and Muse cell administration increased tissue VEGF level and expression of angiogenesis-related genes in the ischemic limb. Moreover, we found that Muse cell administration increased M2 macrophage and gene expression ratio of anti-inflammatory genes to proinflammatory gene, iNOS, in the ischemic limb. Lastly, we administered Muse cell intravenously at day 1 and 3, or high-dose BM-MNCs intramuscularly at day1 after the HLI surgery and found that repetitive Muse cell administration resulted in significantly enhanced blood flow recovery in the ischemic limb compared to high-dose BM-MNCs administration. Conclusions: Using an animal model, we demonstrated that intravenous Muse cell transplantation exerts robust therapeutic effects on limb ischemia injury. Therefore, Muse cell-based therapy may provide a novel therapeutic approach for patients with severe limb ischemia.

Astragaloside IV promotes the angiogenic capacity of adipose-derived mesenchymal stem cells in a hindlimb ischemia model by FAK phosphorylation via CXCR2

BackgroundTherapeutic angiogenesis by transplantation of autologous/allogeneic adipose stem cells (ADSCs) is a potential method for the treatment of critical limb ischemia (CLI). However, the therapeutic efficiency is limited by poor viability, adhesion, migration and differentiation after cell transplantation into the target area. Astragaloside IV (AS-IV), one of the main active components of Astragalus, has been widely used in the treatment of ischemic diseases and can promote cell proliferation and angiogenesis. However, there is no report on the effect of AS-IV on ADSCs and its effect on hindlimb ischemia through cell transplantation. PurposeThe purpose of this study was to elucidate that AS-IV pretreatment enhances the therapeutic effect of ADSC on critical limb ischemia, and to characterize the underlying molecular mechanisms. MethodsADSCs were obtained and pretreated with the different concentration of AS-IV. In vitro, we analyzed the influence of AS-IV on ADSC proliferation, migration, angiogenesis and recruitment of human umbilical vein endothelial cells (HUVECs) and analyzed the relevant molecular mechanism. In vivo, we injected drug-pretreated ADSCs into a Matrigel or hindlimb ischemia model and evaluated the therapeutic effect by the laser Doppler perfusion index, immunofluorescence, and histopathology. ResultsIn vitro experiments showed that AS-IV improved ADSC migration, angiogenesis and endothelial recruitment. The molecular mechanism may be related to the upregulation of CXC receptor 2 (CXCR2) to promote the phosphorylation of focal adhesion kinase (FAK). In vivo, Matrigel plug assay showed that ADSCs pretreated with AS-IV have stronger angiogenic potential. The laser Doppler perfusion index of the hindlimbs of mice in the ADSC/AS-IV group was significantly higher than the laser Doppler perfusion index of the hindlimbs of mice of the ADSC group and the control group, and the microvessel density was significantly increased. ConclusionOur results demonstrate that AS-IV pretreatment of ADSC improves their therapeutic efficacy in ameliorating severe limb exclusion symptomology through CXCR2 induced FAK phosphorylation, which will bring new insights into the treatment of severe limb ischemia.

Combination Stem Cell Therapy for the Treatment of Severe Limb Ischemia: Safety and Efficacy Analysis

The infusion of a source of endothelial progenitors (EPCs) to limb ischemia (LB) patients has been used to increase angiogenesis. Because the formation of new blood vessels involves, in addition to EPCs, other cells and angiogenic regulators, we postulate that a combination cell therapy including EPCs and mesenchymal stem cells (a source of pericytes progenitors and angiogenic regulators) may represent a preferential stimuli for the development of blood vessels. In this phase I clinical trial, patients with LI were infused with a cell product consisting of autologous bone marrow-derived mononuclear and mesenchymal stem cells. After 10 2 months of follow-up, efficacy assessment demonstrated improvements in walking time, ankle brachial pressure, and quality of life. Concomitantly, angiographic and 99mTc-TF perfusion scintigraphy scores confirmed increased perfusion in the treated limbs. These results show that the use of a combination cell therapy is safe, feasible, and appears effective in patients with LI.

Stem cell and progenitor cell therapy in peripheral artery disease

Atherosclerotic peripheral artery disease (PAD) is a common manifestation of atherosclerosis. The occlusion of large limb arteries leads to ischaemia with claudication which can progress to critical limb ischaemia (CLI) with pain at rest, and to tissue loss. At present, common therapy for CLI is either surgical or endovascular revascularisation aimed at improving blood flow to the affected extremity. However, major amputation and death are still frequent complications. Exploring new strategies for revascularisation of ischaemic limbs is thus of major importance. Bone marrow (BM)-derived stem and progenitor cells have been identified as a potential new therapeutic option to induce therapeutic angiogenesis. Encouraging results of preclinical studies have rapidly led to several small clinical trials, in which BM-derived mononuclear cells were administered to patients with limb ischaemia. Clinical benefits were reported from these trials including improvement of ankle-brachial index (ABI), transcutaneous partial pressure of oxygen (TcPO2), reduction of pain, and decreased need for amputation. Nonetheless, large randomised, placebo-controlled, double-blind studies are necessary and currently ongoing (BONMOT-CLI, JUVENTUS and NCT00498069). Further research relates to the optimal cell type and dosage, the isolation method, the role of colony-stimulating factors, administration route, and the supportive stimulation of cells with reduced functioning due to advanced PAD. Autologous stem cell therapy for ischaemic peripheral disease seems to be a promising new tool for the treatment of severe limb ischaemia. Preliminary evidence has established its safety, feasibility and effectiveness on several important endpoints. Several large endpoints studies are underway to further consolidate this evidence.

Infrapopliteal angioplasty with a long over-the-wire (OTW) balloon in the treatment of severe limb ischemia in diabetic patients: A retrospective study

The use of short balloons in the treatment of infrapopliteal arterial occlusive disease in diabetic patients often has a poor clinical outcome. To retrospectively evaluate the safety and efficacy of a long over-the-wire (OTW) balloon as a primary percutaneous transluminal angioplasty (PTA) treatment for diabetic infrapopliteal severe limb ischemia. Infrapopliteal PTA with a long OTW balloon was performed between April 2007 and March 2008 in 34 patients (53 limbs), including a total of 119 lesions. Patient age was 71.8+/-7.4 years. All patients had limb ischemic symptoms. Angiography was retrospectively analyzed, and every lesion categorized and classified according to its length and severity. The mean follow-up period was 7.4+/-2.6 months. Lower-limb magnetic resonance angiography (MRA) was performed every 3 months during follow-up, and clinical data were collected. Altogether, 92% of patients were successfully treated. Ankle-brachial index (ABI) and transcutaneous oxygen tension (TcPO2) improved from 0.50+/-0.18 and 18.85+/-12.08 mmHg, respectively, before the procedure to 0.81+/-0.12 and 39.85+/-12.67 mmHg, respectively, after the procedure. At the end of follow-up, 29 patients had maintained a stable outcome. Five patients had symptom recurrence, and three of them underwent a second PTA. Two major amputations and four minor amputations were performed, with a 94% limb salvage rate and 59% patency rate. Infrapopliteal PTA with a long OTW balloon was feasible, with encouraging midterm outcome, in the treatment of severe limb ischemia in diabetic patients in this single-center case series. Further research is warranted to evaluate long-term outcome.

Bypass versus angioplasty to treat severe limb ischemia: factors that affect treatment preferences of UK surgeons and interventional radiologists

Objective There is continuing controversy as to whether surgical bypass or angioplasty should be first-line treatment of severe limb ischemia. We undertook this study to examine angiographic and clinical factors that influence the treatment of severe limb ischemia by vascular surgeons and interventional radiologists. Methods Twenty consultant vascular surgeons and 17 consultant vascular interventional radiologists evaluated 596 hypothetical clinical or angiographic scenarios, and recorded whether, in their opinion, the most appropriate first-line treatment was surgical bypass, angioplasty, or primary amputation. Stepwise multiple linear regression was used to identify the factors that significantly affected responses from the entire group and from surgeons and radiologists separately. Results There were significant differences between surgeons and radiologists with regard to how clinical and angiographic variables determined treatment preferences. Increasing disease severity, absence of runoff into the foot, presence of a suitable vein, and tissue loss as opposed to rest pain only (the latter only significant to surgeons) all increased the response score toward surgery. However, surgeons and radiologists weighted each of these factors quite differently. Even in the most complex statistical model, 19% of surgical and 13% of radiologic response variations remained unexplained. Conclusions Individual surgeons and radiologists vary considerably in their views of the relative merits of surgery and angioplasty in patients with severe limb ischemia. This broad gray area mandates the need for randomized controlled trial data to inform joint decision-making and to optimize patient outcome.

Angioplastie transluminale percutanée et ischémie sévère des membres inférieurs

Objectives. – To determine the outcome and the place of transluminal angioplasty (ATL) in the treatment of severe limb ischaemia. Matérial and methods. – Seventy two legs at stage III and IV of Fontaine’s classification have been exclusively traited by endoluminal procedures. The success was valued both on the haemodynamic post-operative improvement of the run-off flow and on the clinical statut leading to the conservation at mid-term of a fonctionnal limb. Patency and survival rate had been valued by actuarial method. Résults. – Seventy percent of the limbs were haemodynamically improved. For the global population, a 48% clinical success rate was obtained at 6 months but 30.5% of limbs were loss. Primary patency rate was respectively 79, 71 and 68% at 6, 12 and 24 month. The quality of the run-off arteries has been the most influential factor. Conclusion. – Endoluminal treatment of chronique limb ischaemia had lead to a clinical improvement in 48% of cases. Multi-stages and distal atherosclerotic disease of this patients limits ATL indications wich results depend of run-off quality.

Gene and other biological therapies for vascular diseases.

Gene transfer and antisense therapy offer novel approaches to the study and treatment of vascular diseases. The localized nature of vascular diseases like restenosis has made the application of genetic material an attractive therapeutic option. Viral and nonviral vectors have been developed to facilitate the entry of foreign DNA or RNA into cells. Vector improvement and production, demonstration of vector safety and demonstration of therapeutic efficacy are among the main present challenges. Various strategies have already been shown to be successful in preventing restenosis in animal models and include: the transfer of the herpes simplex virus thymidine kinase associated with ganciclovir: transfection of the cell cycle regulatory genes encoding for the active form of retinoblastoma gene product (Rb) or the cyclin-dependent kinase inhibitor p21, and antisense therapy. Therapeutic angiogenesis using gene transfer is a new strategy for the treatment of severe limb ischemia. Transfection of DNA encoding for the vascular endothelial growth factor has resulted in increasing collateral flow in animal models of peripheral ischemia. This approach is currently being investigated in a clinical trial in patients with distal ischemia. Other potential targets for genetic treatment in cardiovascular diseases include thrombosis, extracellular matrix synthesis and lipid metabolism.