Barriers in contribution of human mesenchymal stem cells to murine muscle regeneration.

Aim: To study regeneration of damaged human and murine muscle implants and the contribution of added xenogeneic mesenchymal stem cells (MSCs).

Methods: Minced human or mouse skeletal muscle tissues were implanted together with human or mouse MSCs subcutaneously on the back of non-obese diabetic/severe combined immunodeficient mice. The muscle tissues (both human and murine) were minced with scalpels into small pieces (< 1 mm(3)) and aliquoted in portions of 200 mm(3).

Prospects and challenges of induced pluripotent stem cells as a source of hematopoietic stem cells.

Many life-threatening hematological diseases are now treated by bone marrow transplantations, i.e., infusion of hematopoietic stem cells (HSCs).

Pressure ulcers: description of a new model and use of mesenchymal stem cells for repair.

Background: Pressure ulcers (PUs) still represent a heavy burden on many patients and nursing institutions. Our understanding of the pathophysiology and development of new treatments are hampered by the scarcity of suitable animal models.

Objective: Evaluation of the translational value of an easily accessible mouse model.

Myogenic properties of human mesenchymal stem cells derived from three different sources.

Mesenchymal stem cells (MSCs) of mammals have been isolated from many tissues and are characterized by their aptitude to differentiate into bone, cartilage, and fat. Differentiation into cells of other lineages like skeletal muscle, tendon/ligament, nervous tissue, and epithelium has been attained with MSCs derived from some tissues. Whether such abilities are shared by MSCs of all tissues is unknown.

Exploitation of herpesvirus immune evasion strategies to modify the immunogenicity of human mesenchymal stem cell transplants.

Background: Mesenchymal stem cells (MSCs) are multipotent cells residing in the connective tissue of many organs and holding great potential for tissue repair. In culture, human MSCs (hMSCs) are capable of extensive proliferation without showing chromosomal aberrations. Large numbers of hMSCs can thus be acquired from small samples of easily obtainable tissues like fat and bone marrow.

Long-term contribution of human bone marrow mesenchymal stromal cells to skeletal muscle regeneration in mice.

Mesenchymal stromal cells (MSCs) are attractive for cellular therapy of muscular dystrophies as they are easy to procure, can be greatly expanded ex vivo, and contribute to skeletal muscle repair in vivo. However, detailed information about the contribution of bone marrow (BM)-derived human MSCs (BM-hMSCs) to skeletal muscle regeneration in vivo is very limited. Here, we present the results of a comprehensive study of the fate of LacZ-tagged BM-hMSCs following implantation in cardiotoxin (CTX)-injured tibialis anterior muscles (TAMs) of immunodeficient mice.

Anomer-equilibrated streptozotocin solution for the induction of experimental diabetes in mice (Mus musculus).

Streptozotocin is widely used to induce diabetes in laboratory animals through multiple low-dose or single high-dose intraperitoneal injections. HPLC analysis has shown that the composition of the solution may change considerably during the first 2 h after dissolution due to equilibration of the 2 anomers (alpha and beta) of streptozotocin. Because of the drug's alleged instability in solution, the typical recommendation is to administer streptozotocin within 10 min after dissolution.

Phenotypic and functional reversal within the early human hematopoietic compartment.

The fate of phenotypically defined human hematopoietic stem cells (hHSCs) in culture and the link between their surface marker expression profile and function are still controversial. We studied these aspects of hHSC biology by relating the expression of the early lineage markers (ELM) CD33, CD38, and CD71 on the surface of human umbilical cord blood (UCB) CD34(+) cells to their long-term nonobese diabetic/severe combined immunodeficient (NOD/SCID) mouse repopulation activity (LT-SRA). In uncultured UCB samples, LT-SRA was largely confined to the small CD34(+)ELM(-) cell fraction.

Transfer of the full-length dystrophin-coding sequence into muscle cells by a dual high-capacity hybrid viral vector with site-specific integration ability.

Duchenne muscular dystrophy (DMD) is caused by mutations in the DMD gene, making it a potential target for gene therapy. There is, however, a scarcity of vectors that can accommodate the 14-kb DMD cDNA and permanently genetically correct muscle tissue in vivo or proliferating myogenic progenitors in vitro for use in autologous transplantation. Here, a dual high-capacity adenovirus-adeno-associated virus (hcAd/AAV) vector with two full-length human dystrophin-coding sequences flanked by AAV integration-enhancing elements is presented.

Stem cell transplantation for autoimmune disorders. Preclinical experiments.

The clinical use of autologous stem cell transplants for the treatment of refractory severe autoimmune diseases was preceded by convincing proof of its underlying principle in animal models. The various categories of experimental autoimmune disease in laboratory rodents are briefly described here, and the rationale that was used in the selection of suitable experimental autoimmune diseases for translational research is explained. The two models that provided the bulk of the data needed for designing the initial clinical treatment protocols were adjuvant arthritis (AA) and experimental allergic encephalomyelitis (EAE), which were both induced in Buffalo rats.

Phylogenetic aspects of tissue regeneration: role of stem cells. A concise overview.

Many different forms of regeneration are known among the members of the animal kingdom. Invertebrates commonly generate new individuals by sprouting and splitting off of body parts, so that the processes of asexual reproduction and of regeneration as a response to injury can hardly be distinguished. Among the adult vertebrates, regeneration of lost body parts has become exceptional rather than the rule.

Pharmacogenetic heterogeneity of transgene expression in muscle and tumours.

Background: Recombinant adenoviruses are employed to deliver a therapeutic transgene in the liver, muscle or tumour tissue. However, to rationalise this delivery approach, the factors of variation between individuals need to be identified. It is assumed that differences between inbred strains of laboratory animals are considered to reflect differences between patients.

Experimental basis for the treatment of autoimmune diseases with autologous hematopoietic stem cell transplantation.

Preclinical research with autologous bone marrow transplantation has been performed in two models of autoimmune disease using Buffalo rats. In this strain, adjuvant arthritis develops as a chronic progressive systemic type of arthritis and experimental allergic encephalomyelitis as a chronic remitting relapsing disease. In these models, the influence of various treatment parameters was studied, among them the conditioning regimen, the composition of the graft and the effect of reimmunization of cured animals.

Genetic heterogeneity in response to adenovirus gene therapy.

Background: After intravenous delivery of the adenoviral vector into rats or mice, 95-99% of the encoded protein is produced in the hepatocytes. We observed, as have others, that the early expression levels of the vector encoded protein vary, greatly, within a species, from one animal strain to another. This study was initiated to determine the molecular mechanism causing the difference: hepatic transfection, transcription or translation.

Experimental basis of hematopoietic stem cell transplantation for treatment of autoimmune diseases.

Experiments with animal models of autoimmune disease provided the rational and stimulus for the current, clinical studies of autologous stem cell transplantation for the treatment of a variety of severe, refractory, autoimmune diseases. The discoveries that led to the recognition of the key role of hematopoietic stem cells and the successful treatment of autoimmune diseases with bone marrow transplants are reviewed. The relevance of spontaneous and induced autoimmune disease models for the development of clinical treatment regimens is discussed.

A comparison of efficacy and toxicity between electroporation and adenoviral gene transfer.

Background: Electroporation of skeletal muscle after injection of naked DNA was shown by others to increase transgene expression. Information regarding tissue damage caused by electroporation is conflicting. It is also not well known how plasmid electroporation compares with transfection by adenoviral vectors.

Adenoviral gene transfer of angiostatic ATF-BPTI inhibits tumour growth.

Background: The outgrowth of new vessels--angiogenesis--in the tumour mass is considered to be a limiting factor of tumour growth. To inhibit the matrix lysis that is part of the tumour angiogenesis, we employed the chimeric protein mhATF-BPTI, composed of the receptor binding part of the urokinase (ATF) linked to an inhibitor of plasmin (BPTI).

Methods: For delivery, recombinant adenovirus encoding the transgene of interest was injected intravenously or locally into the tumour.

Immune ablation and stem-cell therapy in autoimmune disease. Experimental basis for autologous stem-cell transplantation.

Treatment of rats suffering from florid chronic progressive systemic arthritis or from chronic remitting/relapsing encephalomyelitis with autologous bone marrow transplantation (BMT) is highly effective. This finding was unexpected as the genotype of the bone marrow largely determines the susceptibility of both spontaneous and induced autoimmune diseases in rodents. The success of autologous stem-cell transplantation depends on the completeness of eradication of the effectors of autoimmune disease, in other words activated and memory T lymphocytes.