Authors: Bo Zheng, Baohong Cao, Mihaela Crisan, Bin Sun, Guangheng Li, Alison Logar, Solomon Yap, Jonathan B Pollett, Lauren Drowley, Theresa Cassino, Burhan Gharaibeh, Bridget M Deasy, Johnny Huard & Bruno Péault
Title: Prospective Identification of Myogenic Endothelial Cells in Human Skeletal Muscle
Summary: This manuscript documents anatomic, molecular and developmental relationships between endothelial and myogenic cells within human skeletal muscle. Cells coexpressing myogenic and endothelial cell markers (CD56, CD34, CD144) were identified by immunohistochemistry and flow cytometry. These myoendothelial cells regenerate myofibers in the injured skeletal muscle of severe combined immunodeficiency mice more effectively than CD56+ myogenic progenitors. They proliferate long term, retain a normal karyotype, are not tumorigenic and survive better under oxidative stress than CD56+ myogenic cells. Clonally derived myoendothelial cells differentiate into myogenic, osteogenic and chondrogenic cells in culture. Myoendothelial cells are amenable to biotechnological handling, including purification by flow cytometry and long-term expansion in vitro, and may have potential for the treatment of human muscle disease.
Authors: Zheng B, Caro B, Crisan M, Sun B Li G, Logar A, Yap S, Pollett JB, Drowley L, Cassino T, Gharaibeh B, Deasy BM, Huard J, Peault B
Title: Prospective identification of myogenic endothelial cells in human skeletal muscle.
Summary: Myoendothelial cells taken from the blood vessels are much more efficient at forming muscle than other sources of stem cells known as satellite and endothelial cells. A thousand myoendothelial cells transplanted into the injured skeletal muscle of immunodeficient mice produced, on average, 89 muscle fibers, compared with nine and five muscle fibers for endothelial and satellite cells, respectively. Myoendothelial cells also showed no propensity to form tumors, a concern with other stem cell therapies.
Author(s): Péault B, Rudnicki M, Torrente Y, Cossu G, Tremblay JP, Partridge T, Gussoni E, Kunkel LM, Huard J.
Title: Stem and progenitor cells in skeletal muscle development, maintenance, and therapy
Summary: Satellite cells are dormant progenitors located at the periphery of skeletal myofibers that can be triggered to proliferate for both self-renewal and differentiation into myogenic cells. In addition to anatomic location, satellite cells are typified by markers such as M-cadherin, Pax7, Myf5, and neural cell adhesion molecule-1. The Pax3 and Pax7 transcription factors play essential roles in the early specification, migration, and myogenic differentiation of satellite cells. In addition to muscle-committed satellite cells, multi-lineage stem cells encountered in embryonic, as well as adult, tissues exhibit myogenic potential in experimental conditions. These multi-lineage stem cells include side-population cells, muscle-derived stem cells (MDSCs), and mesoangioblasts. Although the ontogenic derivation, identity, and localization of these non-conventional myogenic cells remain elusive, recent results suggest their ultimate origin in blood vessel walls. Indeed, purified pericytes and endothelium-related cells demonstrate high myogenic potential in culture and in vivo. Allogeneic myoblasts transplanted into Duchenne muscular dystrophy (DMD) patients have been, in early trials, largely inefficient owing to immune rejection, rapid death, and limited intramuscular migration–all obstacles that are now being alleviated, at least in part, by more efficient immunosuppression and escalated cell doses. As an alternative to myoblast transplantation, stem cells such as mesoangioblasts and CD133+ progenitors administered through blood circulation have recently shown great potential to regenerate dystrophic muscle.
Author(s): Peault B, Rudnicki M, Torrente Y, Cossu G, Tremblay JP, Partridge T, Gussoni E, Kunkel LM, Huard J.
Title: Stem and Progenitor Cells in Skeletal Muscle Development, Maintenance, and Therapy
Summary: Satellite cells are dormant progenitors located at the periphery of skeletal myofibers that can be triggered to proliferate for both self-renewal and differentiation into myogenic cells. In addition to anatomic location, satellite cells are typified by markers such as M-cadherin, Pax7, Myf5, and neural cell adhesion molecule-1. The Pax3 and Pax7 transcription factors play essential roles in the early specification, migration, and myogenic differentiation of satellite cells. In addition to muscle-committed satellite cells, multi-lineage stem cells encountered in embryonic, as well as adult, tissues exhibit myogenic potential in experimental conditions. These multi-lineage stem cells include side-population cells, muscle-derived stem cells (MDSCs), and mesoangioblasts. Although the ontogenic derivation, identity, and localization of these non-conventional myogenic cells remain elusive, recent results suggest their ultimate origin in blood vessel walls. Indeed, purified pericytes and endothelium-related cells demonstrate high myogenic potential in culture and in vivo. Allogeneic myoblasts transplanted into Duchenne muscular dystrophy (DMD) patients have been, in early trials, largely inefficient owing to immune rejection, rapid death, and limited intramuscular migration-all obstacles that are now being alleviated, at least in part, by more efficient immunosuppression and escalated cell doses. As an alternative to myoblast transplantation, stem cells such as mesoangioblasts and CD133+ progenitors administered through blood circulation have recently shown great potential to regenerate dystrophic muscle.
Author(s): Thomas W. Gilbert, Michael S. Sacks, Jonathan S. Grashow, Savio L.-Y. Woo, Stephen F. Badylak, Michael B. Chancellor
Title: Fiber Kinematics of Small Intestinal Submucosa Under Biaxial and Uniaxial Stretch
Summary: Improving our understanding of the design requirements of biologically derived collagenous scaffolds is necessary for their effective use in tissue reconstruction. In the present study, the collagen fiber kinematics of small intestinal submucosa (SIS) was quantified using small angle light scattering (SALS) while the specimen was subjected to prescribed uniaxial or biaxial strain paths. A modified biaxial stretching device based on Billiar and Sacks (J. Biomech., 30, pp. 753–7, 1997) was used, with a real-time analysis of the fiber kinematics made possible due to the natural translucency of SIS. Results indicated that the angular distribution of collagen fibers in specimens subjected to 10% equibiaxial strain was not significantly different from the initial unloaded condition, regardless of the loading path _p=0.31_. Both 10% strip biaxial stretch and uniaxial stretches of greater than 5% in the preferred fiber direction led to an increase in the collagen fiber alignment along the same direction, while 10% strip biaxial stretch in the cross preferred fiber direction led to a broadening of the distribution. While an affine deformation model accurately predicted the experimental findings for a biaxial strain state, uniaxial stretch paths were not accurately predicted. Nonaffine structural models will be necessary to fully predict the fiber kinematics under large uniaxial strains in SIS.
Author(s): Manuela Tavian, Bo Zheng, Estelle Oberlin, Mihaela Crisan, Bin Sun, Johnny Huard, and Bruno Peault
Title: The Vascular Wall as a Source of Stem Cells
Summary: We have characterized the emerging hematopoietic system in the human embryo and fetus. Two embryonic organs, the yolk sac and aorta, support the primary emergence of hematopoietic stem cells (HSCs), but only the latter contributes lymphomyeloid stem cells for definitive, adult-type hematopoiesis. A common feature of intra- and extraembryonic hematopoiesis is that in both locations hematopoietic cells emerge in close vicinity to vascular endothelial cells. We have provided evidence that a population of angiohematopoietic mesodermal stem cells, marked by the expression of flk-1 and the novel BB9/ACE antigen, migrate from the paraaortic splanchnopleura into the ventral part of the aorta, where they give rise to hemogenic endothelial cells and, in turn, hematopoietic cells. HSCs also appear to develop from endothelium in the embryonic liver and fetal bone marrow, albeit at a much lower frequency. This would imply that the organism does not function during its whole life on a stock of hematopoietic stem cells established in the early embryo, as is usually accepted. We next examined whether the vessel wall can contribute stem cells for other cell lineages, primarily in the model of adult skeletal muscle regeneration. By immunohistochemistry and flow cytometry, we documented the existence in skeletal muscle, besides genuine endothelial and myogenic cells, of a subset of satellite cells that coexpress endothelial cell markers. This suggested the existence of a continuum of differentiation from vascular cells to endothelial cells that was confirmed in long-term culture. The regenerating capacity of these cells expressing both myogenic and endothelial markers is being investigated in skeletal and cardiac muscle, and the results are being compared with those generated by satellite cells. Altogether, these results point to a generalized progenitor potential of a subset of endothelial, or endothelium-like, cells in blood vessel walls, in pre- and postnatal life.
Author(s): Ryosuke Kuroda, Arvydas Usas, Seiji Kubo, Karin Corsi, Hairong Peng, Tim Rose, James Cummins, Freddie H. Fu, Johnny Huard
Title: Cartilage repair using bone morphogenetic protein 4 and muscle-derived stem cells
Summary: Objective: Muscle-derived stem cells (MDSCs) isolated from mouse skeletal muscle exhibit long-time proliferation, high self-renewal, and multipotent differentiation. This study was undertaken to investigate the ability of MDSCs that were retrovirally transduced to express bone morphogenetic protein 4 (BMP-4) to differentiate into chondrocytes in vitro and in vivo and enhance articular cartilage repair. Methods: Using monolayer and micromass pellet culture systems, we evaluated the in vitro chondrogenic differentiation of LacZ- and BMP-4-transduced MDSCs with or without transforming growth factor 1 (TGF1) stimulation. We used a nude rat model of a full-thickness articular cartilage defect to assess the duration of LacZ transgene expression and evaluate the ability of transplanted cells to acquire a chondrocytic phenotype. We evaluated cartilage repair macroscopically and histologically 4, 8, 12, and 24 weeks after surgery, and performed histologic grading of the repaired tissues. Results: BMP-4-expressing MDSCs acquired a chondrocytic phenotype in vitro more effectively than did MDSCs expressing only LacZ; the addition of TGF1 did not alter chondrogenic differentiation of the BMP-4-transduced MDSCs. LacZ expression within the repaired tissue continued for up to 12 weeks. Four weeks after surgery, we detected donor cells that coexpressed -galactosidase and type II collagen. Histologic scoring of the defect sites 24 weeks after transplantation revealed significantly better cartilage repair in animals that received BMP-4-transduced MDSCs than in those that received MDSCs expressing only LacZ. Conclusion: Local delivery of BMP-4 by genetically engineered MDSCs enhanced chondrogenesis and significantly improved articular cartilage repair in rats.
Author(s): Li-Ying Sung1, 6, Shaorong Gao1, 6, Hongmei Shen2, Hui Yu2, Yifang Song2, Sadie L Smith1, Ching-Chien Chang1, Kimiko Inoue1, Lynn Kuo3, Jin Lian4, Ao Li5, X Cindy Tian1, David P Tuck5, Sherman M Weissman4, Xiangzhong Yang1 & Tao Cheng2
1-Center for Regenerative Biology and Department of Animal Science, University of Connecticut, Storrs, Connecticut 06269, USA.
2-Cancer Stem Cell Program, University of Pittsburgh Cancer Institute and Department of Radiation Oncology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213, USA.
3-Department of Statistics, University of Connecticut, Storrs, Connecticut 06269, USA.
4-Department of Genetics, Yale University School of Medicine, New Haven, Connecticut 06510, USA.
5-Department of Pathology, Yale University School of Medicine, New Haven, Connecticut 06510, USA.
6-These authors contributed equally to this work.
Author(s): Satdarshan P.S. Monga*, Mariah S. Hout, Matt J. Baun, Amanda Micsenyi*, Peggy Muller*, Lekha Tummalapalli*, Aarati R. Ranade, Jian-Hua Luo*, Stephen C. Strom* and Jörg C. Gerlach¶
From the Departments of Pathology,* Medicine (Gastroenterology), and Surgery and Bioengineering, McGowan Institute for Regenerative Medicine, and the Department of Pharmacy, University of Pittsburgh, Pittsburgh, Pennsylvania; and the Department of Surgery,¶ Charité-Campus Virchow, Humboldt University, Berlin, Germany
Summary: By integrating mesoscale models for hydrodynamics and micromechanics, we examine the fluid-driven motion of pairs of capsules on a compliant, adhesive substrate. The capsules, modeled as fluid filled elastic shells, represent ex vivo cells or polymeric microcapsules. We show that both the relative and the average velocities of two closely spaced, rolling capsules depends on the elasticity of the capsules, the adhesive interaction between the capsules and the substrate, and the compliance of the substrate. We first focused on a stiff surface and found that pairs of rigid capsules always separate from each other, while for deformable capsules, the dynamic behavior depends critically on the strength of the adhesive interaction. For strong adhesion to the substrate, the capsules again roll away from each other, while for a relatively weak adhesion, the capsules actually approach each other. In the case of soft substrates, any significant deformations of the surface that are caused by the capsules give rise to a force that propels the particles to move rapidly apart. Thus, in the case of strong adhesion between the capsules and the soft substrates, both rigid and flexible capsules are driven to separate. On the other hand, for weak adhesion, the elastic particles approach each other, similar to the behavior on stiff surfaces. These findings reveal that the interactions between the capsules are mediated by the nature of the underlying layer. We can harness this information to design surfaces that actively control the relative separation between the capsules. This could be utilized to regulate the motion of biological cells, as well as polymeric microcapsules, and thus, could prove to be useful in various biological assays or tissue engineering studies.
Author(s): Paul V. Kochupura, MD; Evren U. Azeloglu, MS; Damon J. Kelly, MS; Sergey V. Doronin, PhD; Stephen F. Badylak, MD, PhD, DVM; Irvin B. Krukenkamp, MD; Ira S. Cohen, MD, PhD; Glenn R. Gaudette, PhD
From the Departments of Surgery (P.V.K., I.B.K., G.R.G.) and Biomedical Engineering (E.U.A., D.J.K., I.B.K., G.R.G.), Stony Brook University, Stony Brook, New York; the McGowan Institute for Regenerative Medicine (S.F.B.), Pittsburgh, Pa; the Institute of Molecular Cardiology (S.V.D., I.B.K., I.S.C., G.R.G.), Stony Brook, New York; and the Department of Surgery (G.R.G.), University of Massachusetts Medical School, Worcester, Mass.
Author(s): Srikanth Ranganathan (1), Eric Williams (2), Philip Ganchev (2), Vanathi Gopalakrishnan (2), David Lacomis (3), Leo Urbinelli (4), Kristyn Newhall (4), Merit E. Cudkowicz (4), Robert H. Brown Jr. (5) and Robert Bowser (1)
1) Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
2) Center for Biomedical Informatics, University of Pittsburgh, Pittsburgh, PA, USA
3) Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
4) Neurology Clinical Trials Unit, Massachusetts General Hospital East, Charlestown, MA, USA
5) Day Neuromuscular Research Laboratory, Massachusetts General Hospital East, Charlestown, MA, USA
Author(s): Hideki Oshima, Thomas R. Payne, Kenneth L. Urish, Tetsuro Sakai, Yiqun Ling, Burhan Gharaibeh, Kimimasa Tobita, Bradley B. Keller, James H. Cummins, and Johnny Huard
Title: Differential Myocardial Infarct Repair with Muscle Stem Cells Compared to Myoblasts
Summary: Myoblast transplantation for cardiac repair has generated beneficial results in both animals and humans; however, poor viability and poor engraftment of myoblasts after implantation in vivo limit their regeneration capacity. We and others have identified and isolated a subpopulation of skeletal muscle-derived stem cells (MDSCs) that regenerate skeletal muscle more effectively than myoblasts.
Title: Migfilin and its binding partners: from cell biology to human diseases
Summary: Links between the plasma membrane and the actin cytoskeleton are essential for maintaining tissue integrity and for controlling cell morphology and behavior. Studies over the past several decades have identified dozens of components of such junctions. One of the most recently identified is migfilin, a widely expressed protein consisting of an N-terminal filamin-binding domain, a central proline-rich domain and three C-terminal LIM domains. Migfilin is recruited to cell-matrix contacts in response to adhesion and colocalizes with beta-catenin at cell-cell junctions in epithelial and endothelial cells. Migfilin also travels from the cytoplasm into the nucleus, a process that is regulated by RNA splicing and calcium signaling. Through interactions with multiple binding partners, including Mig-2, filamin and VASP, migfilin links the cell adhesion structures to the actin cytoskeleton. It regulates actin remodeling, cell morphology and motility. In nuclei, migfilin interacts with the cardiac transcriptional factor CSX/NKX2-5 and promotes cardiomyocyte differentiation. It probably functions as a key regulator both at cell adhesion sites and nuclei, coordinating multiple cellular processes, and is implicated in the pathogenesis of several human diseases.