Myoblast Transplantation Research Articles

Our journey with François Gros.

Gillian Butler-Browne began working on muscle at the Institut Pasteur in the laboratory of François Gros in 1978. She characterized the expression profile of different myosin isoforms during both human and rodent development. Vincent Mouly joined this laboratory for his PhD in 1982, and defined the different populations of myoblasts appearing during development in birds and then in humans. Together, they demonstrated the impact of the limit in proliferation of the precursor cells on the regenerative capacity of human skeletal muscle, and their group developed models to evaluate the regenerative potential of skeletal muscle in vitro, measuring the telomeric erosion, and identified the involvement of a stress pathway in the proliferative arrest of muscle progenitors. A platform to produce human immortalized muscle cell lines was the successful result of this research, initiated with François Gros and W. E. Wright. The in vivo regenerative potential of human muscle cells was evaluated by injection into muscles of immunodeficient mice. Their group in collaboration with the clinical team of Professor Jean Lacau St-Guily and Professor Sophie Perié completed a successful autologous myoblast transplantation clinical trial for Oculo-pharyngeal muscular dystrophy. This common scientific career was made possible thanks to the precious and always benevolent support of François Gros.

Retraction: Transplantation of HGF gene-engineered skeletal myoblasts improve infarction recovery in a rat myocardial ischemia model.

Retraction: Transplantation of HGF gene-engineered skeletal myoblasts improve infarction recovery in a rat myocardial ischemia model.

Portrait of Dysferlinopathy: Diagnosis and Development of Therapy.

Dysferlinopathy is a disease caused by a dysferlin deficiency due to mutations in the DYSF gene. Dysferlin is a membrane protein in the sarcolemma and is involved in different functions, such as membrane repair and vesicle fusion, T-tubule development and maintenance, Ca2+ signalling, and the regulation of various molecules. Miyoshi Myopathy type 1 (MMD1) and Limb-Girdle Muscular Dystrophy 2B/R2 (LGMD2B/LGMDR2) are two possible clinical presentations, yet the same mutations can cause both presentations in the same family. They are therefore grouped under the name dysferlinopathy. Onset is typically during the teenage years or young adulthood and is characterized by a loss of Achilles tendon reflexes and difficulty in standing on tiptoes or climbing stairs, followed by a slow progressive loss of strength in limb muscles. The MRI pattern of patient muscles and their biopsies show various fibre sizes, necrotic and regenerative fibres, and fat and connective tissue accumulation. Recent tools were developed for diagnosis and research, especially to evaluate the evolution of the patient condition and to prevent misdiagnosis caused by similarities with polymyositis and Charcot-Marie-Tooth disease. The specific characteristic of dysferlinopathy is dysferlin deficiency. Recently, mouse models with patient mutations were developed to study genetic approaches to treat dysferlinopathy. The research fields for dysferlinopathy therapy include symptomatic treatments, as well as antisense-mediated exon skipping, myoblast transplantation, and gene editing.

In utero transplantation of myoblasts and adipose-derived mesenchymal stem cells to murine models of Duchenne muscular dystrophy does not lead to engraftment and frequently results in fetal death.

IntroductionDuchenne muscular dystrophy (DMD) is a progressive disease that leads to damage of muscle and myocardium due to genetic abnormalities in the dystrophin gene. In utero cell transplantation that might facilitate allogenic transplantation is worth considering to treat this disease.MethodsWe performed allogeneic in utero transplantation of GFP-positive myoblasts and adipose-derived mesenchymal stem cells into murine DMD model animals. The transplantation route in this study was fetal intraperitoneal transplantation and transplacental transplantation. Transplanted animals were examined at 4-weeks old by immunofluorescence staining and RT-qPCR.ResultsNo GFP-positive cells were found by immunofluorescence staining of skeletal muscle and no GFP mRNA was detected by RT-qPCR in any animal, transplantation method and cell type. Compared with previous reports, myoblast transplantation exhibited an equivalent mortality rate, but adipose-derived stem cell (ASC) transplantation produced a higher mortality rate.ConclusionsIn utero transplantation of myoblasts or ASCs to murine models of DMD does not lead to engraftment and, in ASC transplantation primarily, frequently results in fetal death.

The fibrotic niche impairs satellite cell function and muscle regeneration in mouse models of Marfan syndrome.

It has been suggested that the proliferation and early differentiation of myoblasts are impaired in Marfan syndrome (MFS) mice during muscle regeneration. However, the underlying cellular and molecular mechanisms remain poorly understood. Here, we investigated muscle regeneration in MFS mouse models by analyzing the influence of the fibrotic niche on satellite cell function. In vivo, ex vivo, and in vitro experiments were performed. In addition, we evaluated the effect of the pharmacological inhibition of fibrosis using Ang-(1-7) on regenerating skeletal muscles of MFS mice. The skeletal muscle of MFS mice shows an increased accumulation of collagen fibers (81.2%), number of fibroblasts (157.1%), and Smad2/3 signaling (110.5%), as well as an aberrant number of fibro-adipogenic progenitor cells in response to injury compared with wild-type mice. There was an increased number of proinflammatory and anti-inflammatory macrophages (3.6- and 3.1-fold, respectively) in regenerating muscles of wild-type mice, but not in the regenerating muscles of MFS mice. Our data show that proliferation and differentiation of satellite cells are altered (p ≤ 0.05) in MFS mice. Myoblast transplantation assay revealed that the regenerating muscles from MFS mice have reduced satellite cell self-renewal capacity (74.7%). In addition, we found that treatment with Ang-(1-7) reduces fibrosis (71.6%) and ameliorates satellite cell dysfunction (p ≤ 0.05) and muscle contractile function (p ≤ 0.05) in MFS mice. The fibrotic niche, caused by Fbn1 mutations, reduces the myogenic potential of satellite cells, affecting structural and functional muscle regeneration. In addition, the fibrosis inhibitor Ang-(1-7) partially counteracts satellite cell abnormalities and restores myofiber size and contractile force in regenerating muscles.

Update for Duchenne Muscular Dystrophy - Hope for Causal Treatment of a Disorder Presenting in Early Childhood?

Duchenne muscular dystrophy (DMD) is a lethal muscle wasting disease that affects 1 in 3,600 to 6,000 males. DMD is not curable until today. In this mini-review, myoblast transplantation and stem cell therapy, read-through therapy, antisense oligonucleotide-mediated therapy, vector-mediated gene therapy, and CRISPR/Cas9-mediated gene editing are shortly addressed, approaches which alone or combined have the potential for causal treatment of DMD.

CRISPR/Cas9 editing of directly reprogrammed myogenic progenitors restores dystrophin expression in a mouse model of muscular dystrophy.

SummaryGenetic mutations in dystrophin manifest in Duchenne muscular dystrophy (DMD), the most commonly inherited muscle disease. Here, we report on reprogramming of fibroblasts from two DMD mouse models into induced myogenic progenitor cells (iMPCs) by MyoD overexpression in concert with small molecule treatment. DMD iMPCs proliferate extensively, while expressing myogenic stem cell markers including Pax7 and Myf5. Additionally, DMD iMPCs readily give rise to multinucleated myofibers that express mature skeletal muscle markers; however, they lack DYSTROPHIN expression. Utilizing an exon skipping-based approach with CRISPR/Cas9, we report on genetic correction of the dystrophin mutation in DMD iMPCs and restoration of protein expression in vitro. Furthermore, engraftment of corrected DMD iMPCs into the muscles of dystrophic mice restored DYSTROPHIN expression and contributed to the muscle stem cell reservoir. Collectively, our findings report on a novel in vitro cellular model for DMD and utilize it in conjunction with gene editing to restore DYSTROPHIN expression in vivo.

Assessment of Muscle Function Following hiPSC-Derived Myoblast Transplantation in Dystrophic Mice.

Muscular dystrophies are caused by genetic variants in genes encoding for proteins important for muscle structure or function, leading to a loss of muscle integrity and muscle wasting. To this day, no cure has been found for these diseases. Different therapeutic approaches are under intensive investigation. Cellular therapy has been extensively studied for diseases such as Duchenne Muscular Dystrophy, a debilitating disease caused by a mutation in the DMD gene, encoding for the dystrophin protein. Healthy myogenic cells transplanted into dystrophic muscles have the potential to engraft at long-term and fuse to donate their nuclei to the dystrophin-deficient myofibers, thereby restoring normal gene expression. Despite promising preclinical studies, the clinical trials had limited success so far due to many technical limitations. The recent technological advances in induced-pluripotent stem cells and genome editing opened new opportunities in this field. One of the keys to efficiently translate these new technologies into clinical benefits is to use relevant endpoints for preclinical studies. Considering that dystrophic muscles are susceptible to contraction-induced injury, the assessment of their resistance to repeated eccentric contractions is an optimal outcome to evaluate their functional recovery following cell transplantation. This protocol describes the procedure to generate induced-pluripotent stem cell-derived myoblasts, transplant these cells into skeletal muscle of immunosuppressed dystrophic mice, and assess muscle function in situ by measuring the resistance of the transplanted muscle to repeated eccentric contractions. © 2022 Wiley Periodicals LLC. Basic Protocol 1: Generation of hiPSC-derived myoblasts. Basic Protocol 2: Transplantation of hiPSC-derived myoblasts in skeletal muscle of dystrophic mice. Basic Protocol 3: Assessment of muscle function in situ.

Towards bioengineered skeletal muscle: recent developments in vitro and in vivo.

Skeletal muscle is a functional tissue that accounts for approximately 40% of the human body mass. It has remarkable regenerative potential, however, trauma and volumetric muscle loss, progressive disease and aging can lead to significant muscle loss that the body cannot recover from. Clinical approaches to address this range from free-flap transfer for traumatic events involving volumetric muscle loss, to myoblast transplantation and gene therapy to replace muscle loss due to sarcopenia and hereditary neuromuscular disorders, however, these interventions are often inadequate. The adoption of engineering paradigms, in particular materials engineering and materials/tissue interfacing in biology and medicine, has given rise to the rapidly growing, multidisciplinary field of bioengineering. These methods have facilitated the development of new biomaterials that sustain cell growth and differentiation based on bionic biomimicry in naturally occurring and synthetic hydrogels and polymers, as well as additive fabrication methods to generate scaffolds that go some way to replicate the structural features of skeletal muscle. Recent advances in biofabrication techniques have resulted in significant improvements to some of these techniques and have also offered promising alternatives for the engineering of living muscle constructs ex vivo to address the loss of significant areas of muscle. This review highlights current research in this area and discusses the next steps required towards making muscle biofabrication a clinical reality.

Recent Progress in Oculopharyngeal Muscular Dystrophy.

Oculopharyngeal muscular dystrophy (OPMD) is a late-onset intractable myopathy, characterized by slowly progressive ptosis, dysphagia, and proximal limb weakness. It is caused by the abnormal expansion of the alanine-encoding (GCN)n trinucleotide repeat in the exon 1 of the polyadenosine (poly[A]) binding protein nuclear 1 gene (11–18 repeats in OPMD instead of the normal 10 repeats). As the disease progresses, the patients gradually develop a feeling of suffocation, regurgitation of food, and aspiration pneumonia, although the initial symptoms and the progression patterns vary among the patients. Autologous myoblast transplantation may provide therapeutic benefits by reducing swallowing problems in these patients. Therefore, it is important to assemble information on such patients for the introduction of effective treatments in nonendemic areas. Herein, we present a concise review of recent progress in clinical and pathological studies of OPMD and introduce an idea for setting up a nation-wide OPMD disease registry in Japan. Since it is important to understand patients’ unmet medical needs, realize therapeutically targetable symptoms, and identify indices of therapeutic efficacy, our attempt to establish a unique patient registry of OPMD will be a helpful tool to address these urgent issues.

Two-Year Heart Failure Study with Allogeneic Myoblast Transplantation

Objectives: Allogeneic myoblast transplantation (AMT), cyclosporine immunosuppression and coronary artery bypass grafting (CABG) were used to treat end-stage heart failure (HF) subjects without hope of obtaining a heart transplant. Background: Severe myocardial infarction conveys serious complications such as ventricular aneurysm, wall thinning and rupture with fatal consequences. Methods: After meeting Inclusion/Exclusion criteria and signing Patient Informed Consents, 10 HF subjects having mean thinnest wall thickness of 2.21 ± 0.55 mm and ventricular aneurysms were admitted under intensive care. Each subject took daily cyclosporine for three weeks. On the third day of cyclosporine administration, approximately 1 billion myoblasts were implanted through 20 injections into the infarcted myocardium following CABG. Results: Safety No subject suffered death, viral infection, malignant arrhythmia, reduction in cardiac output, immune rejection, or aneurysm growth. No significant difference was found before versus after treatment in the mean levels of blood routine, liver and kidney enzymes, electrolytes and fibrinogen. Efficacy Emission computed tomography (ECT) and magnetic resonance (MR) demonstrated significant increases in viability and perfusion. Mean left ventricular ejection fraction (LVEF) significantly increased (P Conclusions: For the first time, AMT in adjunct use with CABG and cyclosporine demonstrated that cell survived and engrafted in patients with ischemic cardiomyopathy; in this small study the cell transplant was safe. The improvement in heart function and quality of life could be secondary to combined effect of bypass and cell transplant. A larger randomized clinical trial is required to confirm the efficacy.

Manufacturing autologous myoblast for regenerative medicine applications.

Autologous myoblasts have been tested in the treatment of muscle-related diseases. However, the standardization of manufacturing myoblasts is still not established. Here we report a flask and animal-free medium-based method of manufacturing clinical-grade myoblast together with establishing releasing criteria for myoblast products under Good Manufacturing Practice (GMP). Quadriceps muscle biopsy samples were donated from three patients with myogenic ptosis. After biopsy samples were digested through enzymatic dissociation, the cells were grown in T175 flasks (passage 0) and hyperflasks (passage 1) in the animal-free SkGMTM-2 skeletal muscle cell growth medium containing 5% human platelet lysate for 15-17 days. The harvested cells were released based on cell morphology, cell dose, viability, sterility, endotoxin, mycoplasma and immunophenotype. Myotube differentiation was also evaluated. 400 to 500 million myoblast cells were manufactured within 15 to 17 days by the end of passage 1, which met pre-determined releasing criteria. The manufactured myoblast cells could differentiate and fuse into myotubes in vitro, with the possible trend that the donor age may impact the differentiation ability of myoblasts. The present study establishes a flask-based method of manufacturing myoblast in the animal-free medium together with releasing criteria, which is simple, robust, inexpensive and easily reproducible. This study will serve as the validation for a planned phase 1 clinical trial to assess the use of autologous myoblast transplants for the treatment of myogenic ptosis and other myogenic diseases.

Restoration of Functional Full-Length Dystrophin After Intramuscular Transplantation of Foamy Virus-Transduced Myoblasts.

Stem cell therapy is a promising strategy to treat muscle diseases such as Duchenne muscular dystrophy (DMD). To avoid immune rejection of donor cells or donor-derived muscle, autologous cells, which have been genetically modified to express dystrophin, are preferable to cells derived from healthy donors. Restoration of full-length dystrophin (FL-dys) using viral vectors is extremely challenging, due to the limited packaging capacity of the vectors, but we have recently shown that either a foamy viral or lentiviral vector is able to package FL-dys open-reading frame and transduce myoblasts derived from a DMD patient. Differentiated myotubes derived from these transduced cells produced FL-dys. Here, we transplanted the foamy viral dystrophin-corrected DMD myoblasts intramuscularly into mdx nude mice, and showed that the transduced cells contributed to muscle regeneration, expressing FL-dys in nearly all the muscle fibers of donor origin. Furthermore, we showed that the restored FL-dys recruited members of the dystrophin-associated protein complex and neuronal nitric oxide synthase within donor-derived muscle fibers, evidence that the restored dystrophin protein is functional. Dystrophin-expressing donor-derived muscle fibers expressed lower levels of utrophin than host muscle fibers, providing additional evidence of functional improvement of donor-derived myofibers. This is the first in vivo evidence that foamy virus vector-transduced DMD myoblasts can contribute to muscle regeneration and mediate functional dystrophin restoration following their intramuscular transplantation, representing a promising therapeutic strategy for individual small muscles in DMD.

Fabrication of contractile skeletal muscle tissues using directly converted myoblasts from human fibroblasts

Transplantation of stem cell-derived myoblasts is a promising approach for the treatment of skeletal muscle function loss. Myoblasts directly converted from somatic cells that bypass any stem cell intermediary stages can avoid the problem of tumor formation after transplantation. Previously, we reported that co-transduction with the myogenic differentiation 1 (MYOD1) gene and the v-myc avian myelocytomatosis viral oncogene lung carcinoma derived homolog (MYCL) gene efficiently converted human fibroblasts into myoblasts. Although the directly converted myoblasts efficiently fused into multinucleated myotubes invitro and invivo, it is not clear whether they have the contractile ability, which is the most significant phenotype of the muscle. In the present study, we aimed to examine the invitro contractile ability of the myotubes differentiated from the directly converted myoblasts by the overexpression of MYOD1 and MYCL. We fabricated three-dimensional (3D) tissues on a microdevice for force measurement. The 3D culture enhanced the differentiation of the myoblasts into myotubes, which were confirmed by gene expression analysis of skeletal muscle-related genes. The tissues started to generate contractile force in response to electrical stimulation after 4 days of culture, which reached approximately 12μN after 10 days. The addition of IGF-I decreased the contractile force of the 3D tissues, while the use of cryopreserved cells increased it. We confirmed that the tissues fabricated from the cells derived from three different donors generated forces of similar magnitude. Thus, directly converted myoblasts by the overexpression of MYOD1 and MYCL could be a promising cell source for cell therapy.

Inhibition of myostatin improves muscle atrophy in oculopharyngeal muscular dystrophy (OPMD).

BackgroundOculopharyngeal muscular dystrophy (OPMD) is a late‐onset muscle disease affecting one per 80 000 of the general population characterized by profound dysphagia and ptosis, and limb weakness at later stages. Affected muscles are characterized by increased fibrosis and atrophy. Myostatin is a negative regulator of muscle mass, and inhibition of myostatin has been demonstrated to ameliorate symptoms in dystrophic muscles.MethodsIn this study, we performed a systemic delivery of a monoclonal antibody to immunologically block myostatin in the A17 mouse model of OPMD. The mice were administered a weekly dose of 10 mg/kg RK35 intraperitonially for 10 weeks, following which histological analyses were performed on the samples.ResultsThis treatment significantly (P < 0.01) improved body mass (11%) and muscle mass (for the tibialis anterior and extensor digitorum longus by 19% and 41%) in the A17 mice treated with RK35 when compared to saline controls. Similarly, a significantly (P < 0.01) increased muscle strength (18% increase in maximal tetanic force) and myofibre diameter (17% and 44% for the tibialis anterior and extensor digitorum longus), and reduced expression of markers of muscle fibrosis (40% reduction in area of expression), was also observed. No change in the density of intranuclear inclusions (a hallmark of disease progression of OPMD) was however observed.ConclusionsOur study supports the clinical translation of such antibody‐mediated inhibition of myostatin as a treatment of OPMD. This strategy has implications to be used as adjuvant therapies with gene therapy based approaches, or to stabilize the muscle prior to myoblast transplantation.

COMP-Angiopoietin-1 accelerates muscle regeneration through N-cadherin activation

Angiopoietin-1 modulates vascular stability via Tie2 on endothelial cells. In our previous study, we also showed it acts as an inhibitor of cardiomyocyte death. However, it remains poorly understood how Ang1 regulates myogenesis during muscle regeneration. Here we found that COMP-Ang1 (cAng1) enhances muscle regeneration through N-cadherin activation. Muscle fiber regeneration after limb muscle damage by ischemic injury was enhanced with cAng1 treatment. Mechanistically cAng1 directly bound to N-cadherin on the myoblast surface in a Ca2+ dependent manner. The interaction enhanced N-cadherin activation via N-cadherin/p120-catenin complex formation, which in turn activated p38MAPK (but not AKT or ERK) and myogenin expression (but not myoD) as well as increasing myogenin+ cells in/ex vivo. After transplantation of GFP-expressing myoblasts (GFP-MB), we showed an increased generation of GFP+ myotubes with adenovirus cAng1 (Adv-cAng1) injection. Adv-cAng1, however, could not stimulate myotube formation in N-cadherin-depleted GFP-MB. Taken together, this study uncovers the mechanism of how cAng1 promotes myoblast differentiation and muscle regeneration through the N-cadherin/p120-catenin/p38MAPK/myogenin axis.

Stem cells, blood vessels, and angiogenesis as major determinants for musculoskeletal tissue repair.

This manuscript summarizes 20 years of research from my laboratories at the University of Pittsburgh and more recently, at the University of Texas Health Science Center at Houston and the Steadman Philippon Research Institute in Vail, Colorado. The discovery of muscle-derived stem cells (MDSCs) did not arise from a deliberate search to find a novel population of muscle cells with high regenerative potential, but instead was conceived in response to setbacks encountered while working in muscle cell transplantation for Duchenne muscular dystrophy (DMD). DMD is a devastating inherited X-linked muscle disease characterized by progressive muscle weakness due to lack of dystrophin expression in muscle fiber sarcolemma.1 Although the transplantation of normal myoblasts into dystrophin-deficient muscle can restore dystrophin, this approach has been hindered by limited survival (less than 1%) of the injected cells.1 The fact that 99% of the cells were not surviving implantation was seen as a major weakness with this technology by most. My research team decided to investigate which cells represent the 1% of the cells surviving post-implantation. We have subsequently confirmed that the few cells which exhibit high survival post-implantation also display stem cell characteristics, and were termed "muscle-derived stem cells" or MDSCs. Herein, I will describe the origin of these MDSCs, the mechanisms of MDSC action during tissue repair, and finally the development of therapeutic strategies to improve regeneration and repair of musculoskeletal tissues. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:1212-1220, 2019.

Correction: Transplantation of HGF gene-engineered skeletal myoblasts improve infarction recovery in a rat myocardial ischemia model

[This corrects the article DOI: 10.1371/journal.pone.0175807.].

Myoblasts enhance collateral capillary arteriogenesis during chronic ischemia

Peripheral arterial occlusive disease (PAOD) involves peripheral artery occlusion, which causes ischemia (i.e. insufficient blood flow) and is the leading cause of amputation. Natural bypass vessels known as collaterals can preserve downstream tissue viability by creating an alternative route for blood flow. Increased blood flow through preexisting collateral increases shear stress and triggers arteriogenesis, the outward remodeling of arterial vessels. The presence of collaterals improves prognosis in patients with ischemic disease, but many patients never develop identifiable collaterals to relieve peripheral ischemia. Animal models that lack preexisting collaterals are capable of forming collaterals from capillaries that undergo arteriogenesis to become arterialized capillary collaterals (ACC). A treatment to induce the formation of ACCs, particularly in diseased or aged tissues that lack the propensity to form new collateral vessels, could be highly effective in giving protection against ischemia. Exercise is a great therapy for PAOD, since following exercise, resident muscle stem cells known as satellite cells (SCs) activate and regulate local angiogenesis. SCs and their progeny myoblasts secrete factors known to be involved in arteriogenesis (many of these compounds involved in angiogenesis are also involved in arteriogenesis) and the recruitment of other cells involved in remodeling. Therefore, transplanting these putative arteriogenic cells is a potential therapy to recapitulate some of the beneficial effects of exercise therapy. In this study, the lateral feed artery in the spinotrapezius muscle of Balb/C mice was ligated to induce chronic ischemia; myoblasts were transplanted during surgery to enhance arteriogenesis of collateral capillaries. Implanted mice exhibited increased arteriogenesis, ACC diameter increased to 28.11 ± 0.85 μm vs 16.25 ± 0.62 μm in a no transplant control. As corollary, we evaluated the process for cell construct preparation and discovered that cells cultured on scaffold overnight (20.86 ± 1.6 μm) before transplant did not stimulate arteriogenesis as significantly as those who were cultured for 6‐hours only. Limited nutrient supply and gas exchange while incubating on scaffolds could induce stress on myoblast and cause limited reactivity/apoptosis post implant. In summary, myoblast transplantation increases ACC arteriogenesis; however, they need to be transplanted as early as possible post‐harvest from culture flask.Support or Funding InformationFunding: CIRM ( California Institute for Regenerative Medicine)This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

The Impact of Primary Myoblast Transplantation on Functional Vasodilation Following Arteriogenesis in Mice with Diet‐Induced Obesity

Peripheral arterial occlusive disease (PAOD) is characterized by reduced blood flow to the lower limbs, causing claudication and tissue loss. Proximal collateral arteries are natural bypasses to atherosclerotic occlusions in major arteries. A variety of cell‐based therapies have been tested clinically to enhance collateral arteriogenesis. Unfortunately, their efficacy has been poor, despite promising results from early clinical and preclinical studies, possibly because most preclinical studies are performed with mice that lack co‐morbidities present in most patients that are known to impair arteriogenesis. Therefore, additional cell‐types must be explored in animal models that more closely recapitulate the clinical phenotype to determine if pro‐regenerative therapies are a viable treatment for PAOD. Myogenic cells are an attractive candidate, given their co‐localization with the skeletal muscle vasculature niche and their ability to enhance angiogenesis. Therefore, we tested the hypothesis that primary myoblasts would rescue functional vasodilation in the superficial gracilis collateral following arteriogenesis in mice with diet‐induced obesity (DIO).In these studies, C57Bl/6 mice were fed a high‐fat diet from 6‐weeks of age; experiments were performed at about 4‐months of age. First, we performed a pilot study to evaluate functional vasodilation (vasodilation in response to electrically‐stimulated gracilis muscle contraction) in unoperated animals. As expected, vasodilation was impaired in the right (42±4 vs. 58±4 μm) and left (40±5 vs. 52±5 μm), as compared to lean controls.Having established impaired vasodilation in mice with DIO, we ligated the femoral artery in mice to model obesity and the chronic ischemia aspect of PAOD and measured functional vasodilation at day‐7 following surgery. Pilot data suggests that functional vasodilation is reduced in mice with DIO at day‐7 following surgery (resting: 80±10 μm, dilated: 82±8 μm) and that cell transplantation appears to enhance arteriogenesis and improve functional vasodilation (resting: 93±8 μm, dilated: 108±8 μm). Additional experiments are necessary to confirm these findings, but the data suggest that myoblasts strengthen the arteriogenic response. Future studies may involve additional time points to investigate the time course and duration of myoblast‐rescued arteriogenesis and functional vasodilation following arterial occlusion.Support or Funding InformationResearch was funded by the California Institute of Regenerative Medicine.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.