Mesenchymal Stem Cells

Researchers discover that delayed hypoxia treatment can enhance bone healing in a mouse model

The generation of an miRNA-mRNA interaction map in cells that make up the bone marrow niche allows regulatory pathways for signalling factors to be understood.

Alterations in the Cellular Immune Compartment of Patients Treated with Third-Party Mesenchymal Stromal Cells Following Allogeneic Hematopoietic Stem Cell Transplantation

From Stem Cells

Allogeneic hematopoietic stem cell transplantation is often complicated by graft-versus-host disease (GVHD) mediated by the donors immune cells (Ferrara et al) and novel intervention strategies are highly sought after.   Mesenchymal stem cells (MSCs) are known to have immunoregulatory properties and have been applied in clinical trials (Le Blanc et al), although few reports have shed light on the effects of MSCs on the patient's immune system (Dander et al).   Now, in a study published in Stem Cells, researchers from the laboratory of Katarina Le Blanc at the Karolinska University Hospital, Stockholm, Sweden have investigated the alterations in the immune system caused by third-party (i.e. from an unrelated source) MSC treatment to aid in the design of future clinical studies and to establish novel monitoring procedures (Jitschin and Mougiakakos et al).

“Natriuretic Peptide Receptor A Signaling Regulates Stem Cell Recruitment and Angiogenesis: A Model to Study Linkage Between Inflammation and Tumorigenesis”

Natriuretic peptide receptor A (NPRA) is expressed on cells in inflamed or injured tissues and in tumours (Kong et al and Wang et al) and through cGMP-dependent protein kinase (PKG) signalling (Airhart et al and Chen et al), it upregulates genes affecting cell proliferation and inflammation, although a greater level of detail remains to be uncovered. Researchers from the group of Subhra Mohapatra at the University of South Florida, Tampa, Florida, USA have previously shown that NPRA is an early biomarker for human prostate cancer (Wang et al) as well as recently establishing NPRA as a biomarker for melanoma, colon, and pancreatic cancer, and have reasoned that NPRA signaling may promote tumourigenesis by influencing recruitment of immune and progenitor cells, thereby fostering angiogenesis. In their newest study, published in Stem Cells, the group use NPRA-knock out (NPRA-KO) mice as a model and find that that NPRA signaling is indeed linked to angiogenesis partially through progenitor cell recruitment (Mallela et al).

"Comparison of Drug and Cell-Based Delivery: Engineered Adult Mesenchymal Stem Cells Expressing Soluble Tumor Necrosis Factor Receptor II Prevent Arthritis in Mouse and Rat Animal Models"

Tumor necrosis factor-α (TNFα) is a cytokine that mediates normal homeostatic mammalian processes (Schaible et al and Wajant et al) but has been linked to the systemic autoimmune disease Rheumatoid Arthritis (RA), where a TNFα induced cytokine cascade causes inflammation and joint destruction. Blocking TNFα function would therefore seem a viable means to treat RA. Etanercept, a TNF receptor (TNFR) linked to the immunoglobin Fc fragment and two monoclonal antibodies, infliximab and adalimumab are three TNFα inhibitors approved in the United States (Mazza et al), while TNFα blockers certolizumab pegol and golimumab are also utilised (Wallis and Scallon et al). However, the necessity for systemic delivery leads to certain unwanted side-effects, and so site-specific drug action is being sought after. To this end, in a report in Stem Cells Translational Medicine, researchers led by Joseph D. Mosca at Osiris Therapeutics, Inc., Baltimore, Maryland, USA have published the results of their studies on the potential use of mesenchymal stem cell (MSC)-based TNFR delivery and the efficacy of this treatment compared to the use of etanercept (Liu et al).

 “Autologous Bone Marrow-Derived Mesenchymal Stromal Cells for the Treatment of Allograft Rejection After Renal Transplantation”

From Stem Cells Translational Medicine

New means of improving for long-term survival of transplanted kidneys have been searched for unsuccessfully (Pascual et al), but mesenchymal stromal cells (MSCs), which have anti-inflammatory and antifibrotic properties (Franquesa et al, Ninichuk et al and Tolar et al) and prevent renal injury in preclinical models (Casiraghi et al, Ge et al, Inoue et al and Morigi et al) may constitute a new therapeutic option. A relative lack of information (Perico et al and Tan et al), led the group of Ton J. Rabelink at Leiden University Medical Center, Netherlands, in a study published in Stem Cells Translational Medicine, to perform a safety and feasibility study in kidney allograft recipients receiving intravenous infusions of autologous bone marrow (BM) MSCs. Overall they report that this is clinically feasible and safe, and the findings are suggestive of systemic immunosuppression (Reinders et al).

"Injection of Vessel-Derived Stem Cells Prevents Dilated Cardiomyopathy and Promotes Angiogenesis and Endogenous Cardiac Stem Cell Proliferation in mdx/utrn−/− but Not Aged mdx Mouse Models for Duchenne Muscular Dystrophy"

Duchenne muscular dystrophy (DMD) is an X-linked muscle wasting disease affecting approximately 1/3,500 male live births (Emery) and results from mutations in the dystrophin gene. While advances in care have alleviated some aspects of the disease, dilated cardiomyopathy (DCM) incidence has increased. Several pharmacological agents are used to target the symptoms but they do not address the underlying absence of dystrophin or the loss of cardiomyocytes. One potentially exciting avenue of exploration is the transplantation of exogenous stem cells, which can restore dystrophin expression (Berry et al and Sampaolesi et al). Fetal cardiomyocytes (Koh et al) and skeletal muscle-derived stem cells (MDSCs) (Payne et al) have both been investigated after injection directly into the heart. Now, in a study in Stem Cells Translational Medicine, researchers from the group of Suzanne E. Berry at the University of Illinois, USA have studied a role for adult-derived aorta-derived mesoangioblasts (ADMs) in the restoration of dystrophin expression and prevention/alleviation of cardiomyopathy in dystrophin-deficient mdx mice. In this study they show that ADMs induce cardiac marker expression and delayed the onset of DCM in young mice, but could not reverse symptoms in older mice (Chun et al).

"Coculture-Driven Mesenchymal Stem Cell-Differentiated Articular Chondrocyte-Like Cells Support Neocartilage Development"

Mesenchymal stem cells (MSCs) are an attractive source for repair and regeneration of tissue or organ defects. Transplantation of MSCs into defective knee joints to restore cartilage function has yielded some success, although they have yet to pass the pre-clinical and phase I stages towards proper therapeutic use (Koga et al.). A greater understanding of in vivo MSC differentiation mechanisms could aid the widespread use of MSCs through the precise control of cell lineage during in vitro differentiation. Several bioactive agents, such as transforming growth factor-b (TGF-b), insulin-like growth factor-1 (IGF-1), bone morphogenetic protein-2 (BMP-2), and basic fibroblast growth factor (FGF-2), are essential for the chondrogenic differentiation of MSCs (Heng et al.). The mode of delivery of these factors to MSCs has been scrutinised using gradual delivery through means such as gene therapy (Pagnotto et al.) and polymeric vehicles for molecule release (Macdonald et al. and Shah et al.) which have been posited to more closely replicate in vivo conditions (Macdonald et al.). However, an easier method may be the co-culture of MSCs with primary chondrocytes which would secrete proteins such as TGF-b, IGF-1, BMP-2 and FGF-2 slowly over time at physiological concentrations. This has now been studied in detail by researchers from the laboratory of Gilda A. Barabino at the Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, USA and published in Stem Cells Translational Medicine. The researchers found that co-culture mediated differentiation of MSCs with chondrocytes led to the development of robust neocartilage in a three-dimensional agarose system that resisted hypertrophic maturation and calcification (Yang, Lee and Barabino).

"Effects of Medium Supplements on Proliferation, Differentiation Potential, and In Vitro Expansion of Mesenchymal Stem Cells"

Mesenchymal stem cells (MSCs) are multipotent, self-renewing cells with the capacity to differentiate into cells of great therapeutic value (Pitteneger et al.) and are also relatively easy to isolate and cultivate in vitro. However, this long term growth may be detrimental to their overall therapeutic value and therefore optimal growth conditions are being sought. Towards this goal Gharibi and Hughes from King's College London, United Kingdom, in a study published in Stem Cells Translational Medicine, have carried out a comprehensive investigation into the effects of cytokines on the cultivation of MSCs in vitro and demonstrate that medium supplemented with fibroblast growth factor (FGF)-2, platelet-derived growth factor (PDGF)- BB, ascorbic acid (AA), and epidermal growth factor (EGF) leads to the enhancement of the in vitro expansion capacity of MSC cultures.

"Intranasal Delivery of Neural Stem/Progenitor Cells: A Non-invasive Passage to Target Intracerebral Glioma"

The use of neural stem cells and neural progenitor cells (NSPCs) for various central nervous system (CNS) diseases is an emerging therapy which benefits from these cells restorative potential and their ability to preferentially migrate to sites of disease and injury (Muller et al.). However, cellular integration after surgical implantation of allogenic cells derived from embryonic, fetal, or adult tissue is low, while intravascular administration risks intracerebral tumours and increases the risk of accumulation in peripheral organs. This has led researchers from the laboratory of Nils Ole Schmidt at the University Medical Center Hamburg-Eppendorf, Germany to investigate another method of delivery of NSPCs; intranasal administration. The intranasal cavity provides a direct passage to the intracerebral compartment along olfactory pathways and has been used for the administration of drugs and cells previously (Dhuria et al. and Danielyan et al.). In this study, Reitza et al. show the rapid and targeted migration of NSPCs via intranasally accessible pathways toward the intracerebral compartment in a mouse model of intracerebral glioma.