Studies of purification and biological action of synergistic factor from WEHI-3B conditioned medium

Deposited with permission of the author. © Dr. Ian K. McNieceMedia conditioned by a murine myelomonocytic leukemic cell line (WEHI-3B) have been found to produce a haemopoietic growth factor, synergistic factor (SF), which in combination with a source of macrophage-colony stimulating factor (M-CSF), acts on a primitive macrophage progenitor cell to promote the growth of large colonies in agar. These progenitor cells are referred to as high proliferative potential colony forming cells (HPP-CFC) and have been detected in bone marrow from normal mice and mice which have been treated with 5-fluorouracil. The production of SF from WEHI-3B (S SFW) by a variety of methods has been investigated and the highest concentrations of SFW have been obtained by conditioning serum free medium with WEHI-3B cells which have been maintained by transplantation as an ascites tumour in BALB/c mice. The SFW activity was unaffected by storage at 4°C and -20°C, was stable between pH 2.0 and 10.6 and to heat up to 50°C but not above. However, the SFW was unstable to trypsin digestion, 8 M urea at pH 8.0 with and without Mercaptoethanol (ME, 4 mM), and to ME alone at pH 8.0. The SFW has an apparent molecular weight of 25,000 (determined by gel filtration chromatography), it has an isoelectric point in the range of pH 4.0 to 6.5 and does not bind to Con-A Sepharose. A number of separative techniques were investigated in an attempt to purify the SFW from the WEHI-3B CM. A four step purification schedule was devised consisting of anion exchange chromatography, phenyl sepharose chromatography, gel filtration on Sephadex G-100 and mono-0 anion exchange on high pressure liquid chromatography. This schedule resulted in approximately a 128 fold increase in the specific activity with a recovery of approximately 4% of the initial SFW activity. (For full summary open document

The Role of Microenvironment Stromal Cells in Regenerative Medicine

Regenerative medicines offer the potential for treatment and possibly cure of debilitating diseases including heart disease, diabetes, Parkinson's disease and liver failure. Approaches using stem cells from various sources are in pre clinical and clinical testing. The goal of these studies is to deliver cellular products capable of replacing damaged tissue and/or cells. However, the balance between cellular proliferation and differentiation is a carefully controlled process involving a range of growth factors and cytokines produced in large part by tissue stromal cells. These stromal cells make up the tissue microenvironment and appear to be essential for normal homeostasis. We hypothesize that tissue damage in many instances involves damage to the microenvironment resulting in a lack of signals through growth factor networks necessary to maintain survival and proliferation of tissue specific stem cells and progenitor cells. Therefore, optimal repair of disease tissue must account for the damage to the stromal environment. We propose that optimal cellular therapies for regenerative medicine will require combination cellular products consisting of a stromal cell population to reconstitute the microenvironment and to support the survival, proliferation and differentiation of the tissue specific stem cells or progenitor cells

Mesenchymal stem cell therapy for cardiac repair

Stem cell therapy for repair of damaged cardiac tissue is an attractive option to improve the health of the growing number of heart failure patients. Mesenchymal stem cells (MSCs) possess unique properties that may make them a better option for cardiac repair than other cell types. Unlike other adult stem cells, they appear to escape allorecognition by the immune system and they have immune-modulating properties, thus making it possible to consider them for use as an allogeneic cell therapy product. There is a large and growing body of preclinical and early clinical experience with MSC therapy that shows great promise in realizing the potential of stem cell therapy to effect repair of damaged cardiac tissue. This review discusses the mechanism of action of MSC therapy and summarizes the current literature in the field

Genetically modified mesenchymal stem cells (MSCs) promote axonal regeneration and prevent hypersensitivity after spinal cord injury

Neurotrophins and the transplantation of bone marrow-derived stromal cells (MSCs) are both candidate therapies targeting spinal cord injury (SCI). While some studies have suggested the ability of MSCs to transdifferentiate into neural cells, other SCI studies have proposed anti-inflammatory and other mechanisms underlying established beneficial effects. We grafted rat MSCs genetically modified to express MNTS1, a multineurotrophin that binds TrkA, TrkB and TrkC, and p75NTR receptors or MSC-MNTS1/p75− that binds mainly to the Trk receptors. Seven days after contusive SCI, PBS-only, GFP-MSC, MSC-MNTS1/GFP or MSC-MNTS1/p75−/GFP were delivered into the injury epicenter. All transplanted groups showed reduced inflammation and cystic cavity size compared to control SCI rats. Interestingly, transplantation of the MSC-MNTS1 and MSC-MNTS1/p75−, but not the naïve MSCs, enhanced axonal growth and significantly prevented cutaneous hypersensitivity after SCI. Moreover, transplantation of MSC-MNTS1/p75− promoted angiogenesis and modified glial scar formation. These findings suggest that MSCs transduced with a multineurotrophin are effective in promoting cell growth and improving sensory function after SCI. These novel data also provide insight into the neurotrophin-receptor dependent mechanisms through which cellular transplantation leads to functional improvement after experimental SCI. •Genetically modified mesenchymal stem cells (MSCs) enhance axonal growth after SCI.•MSCs transduced to produce a multineurtrophin reduce cutaneous hypersensitivity.•Cellular treatment results in angiogenesis and modification of the glial scar.•Cellular treatments targeting neurotrophins are potential therapeutic agents