Bone Marrow Cells ; cytology ; physiology ; Humans ; Immunity ; Mesenchymal Stromal Cells ; cytology ; physiology

Mesenchymal stem cells (MSC) are thought to be multi-potent cells that have the potential to differentiate into lineages of mesenchymal tissues, including bone, cartilage, tendon, fat, muscle, and marrow stroma during embryo morphogenesis. In recent years, cells that have the characteristics of mesenchymal stem cells were isolated from marrow aspirates of human and a few animals. It was found that these cells retain the characteristics of stem cells in vitro and could be induced to differentiate exclusively into the osteocytic, chondrocytic, myoblastic and adipocytic lineages. It was demonstrated that MSC could heal clinically significant bone and cartilage defects in animal models. The role of MSC in repairing tendon defect was also testified. In addition, for its multi-potential to differentiate into lineages of mesenchymal tissues, MSC could be used as gene vehicle for gene therapy of trauma care.
Animals ; Bone Marrow Cells ; physiology ; Bone Marrow Transplantation ; Bone and Bones ; injuries ; surgery ; Cartilage ; injuries ; surgery ; Cell Differentiation ; Cells, Cultured ; Stem Cells ; physiology ; Tissue Engineering

OBJECTIVETo investigate the therapeutic effectiveness of intracoronary implantation of autologous bone marrow mononuclear cells (BM-MNC) in miniswine model of reperfused myocardial infarction.

METHODSSixteen miniswine myocardial ischemic reperfusion injury models made by ligation of the distal one third segment of left anterior descending artery for 90 minutes were randomized into 2 groups. In BM-MNC group (n = 9), (3.54 +/- 0.90) X 10(8) BM-MNC were intracoronary injected, and in the control group (n = 7), phosphate buffered saline was injected by the same way. Echocardiographic and hemodynamic results, vessel density, and myocardial infarction size were evaluated and compared before and 4 weeks after cell transplantation.

RESULTSIn BM-MNC group, there were no differences between before and 4 weeks after transplantation in aspects of left ventricular ejection fraction (LVEF), interventricular septal thickness, left ventricular lateral and anterior septal wall thickness, cardiac output, or +dp/dtmax. In control group, LVEF, interventricular septal thickness, left ventricular lateral and anterior septal wall thickness, cardiac output, and +dp/dtmax decreased significantly 4 weeks after transplantation (P < 0.05). Left ventricular end-diastolic pressure and -dp/dtmax, did not change significantly before and after cell transplantation in both groups. Capillary density in BM-MNC group was greater than that in control group [(13.39 +/- 6.96)/high power field vs. (3.50 +/- 1.90)/high power field, P < 0.05]. Infarction area assessed by tetrazolium red staining and the infarction percentage decreased in BM-MNC group compared with those in control group (P < 0.05).

CONCLUSIONSTransplantation of BM-MNC into myocardium with ischemic reperfusion injury increases capillary density and decreases infarction area. It has significantly beneficial effect on cardiac systolic function rather than on diastolic function.

Animals ; Bone Marrow Cells ; cytology ; physiology ; Bone Marrow Transplantation ; Capillaries ; physiology ; Echocardiography ; Heart ; anatomy & histology ; physiology ; physiopathology ; Hemodynamics ; Myocardial Ischemia ; Random Allocation ; Swine ; Systole ; physiology ; Transplantation, Autologous ; physiology

To explore the effects of bone marrow cells expanded under different conditions on hematopoietic reconstitution, in the liquid expanded cultural system with several cytokines and/or bone marrow stromal cell layers, the BMMNC of mice were expanded for 5 days. Then the expanded cells were transplanted into the lethal-dose irradiated mice via the caudal vein. The hematopoietic reconstitution of transplanted mice were evaluated by detecting the number of bone marrow nuclear cells and various colony forming cells. The results showed that ex vivo expansion of bone marrow mononuclear cells mediated with cytokines under cultural conditions could not improve the hematopoietic engraftment in post-irradiated mice, but the expansion supported by bone marrow stromal cells could benefit the reconstruction significantly regardless of addition with cytokines. In conclusion, the ex vivo hematopoietic cell expansion supported by bone marrow stromal cells can maintain the properties of the hematopoietic stem/progenitor cells for hematopoietic reconstitution.
Animals ; Bone Marrow Cells ; cytology ; Bone Marrow Transplantation ; mortality ; Female ; Hematopoiesis ; Male ; Mice ; Mice, Inbred BALB C ; Stromal Cells ; physiology

Bone marrow stem cells (BMSC), known for its multipotency to differentiate into various mesenchymal cells such as chodrocyte, osteoblasts, adipocytes, etc, have been actively applied in tissue engineering. BMSC have been successfully isolated from bone marrow aspirate and bone marrow scraping from patients of various ages (13-56 years) with as little as 2ml to 5ml aspirate. BMSC isolated from our laboratory showed the presence of a heterogenous population that showed varying prevalence of surface antigens and the presence of telomerase activity albeit weak. Upon osteogenic induction, alkaline phosphatase activity and mineralization activity were observed.
Bone Marrow Cells/cytology ; *Bone Marrow Transplantation ; Bone Regeneration/physiology ; *Bone Transplantation ; Cell Differentiation/physiology ; *Mesenchymal Stem Cell Transplantation ; Telomerase/metabolism ; *Tissue Engineering

Bone marrow macrophage is an important component of bone marrow microenvironment, which is closely related to hematopoietic regulation and hematopoietic stem cell transplantation(HSCT). Recent studies have shown that bone marrow macrophage is an important part of hematopoietic stem cell niche, which can help regulate the mobilization and function of hematopoietic stem/progenitor cells. After HSCT, the microenvironment of bone marrow is damaged and a large number of macrophages infiltrate into the bone marrow. Regulating the macrophage-related signal pathways can promote the recovery of hematopoiesis and the reconstruction of hematopoietic function. Co-culture of macrophages and hematopoietic stem cells (HSC) in vitro significantly increased the number of HSCs and their ability of clone formation, which suggests that macrophages play an important role in the regulation of hematopoiesis in the hematopoietic microenvironment of bone marrow. This paper reviews the recent research progress on the role of macrophages in bone marrow hematopoietic microenvironment.
Humans ; Bone Marrow/metabolism* ; Hematopoietic Stem Cells/physiology* ; Hematopoiesis/physiology* ; Stem Cell Niche ; Macrophages/metabolism*

Matrix metalloproteinases (MMPs) are endocellular proteolytic enzymes. They are so named because they need Ca2+, Zn2+ and other metal ions as their cofactors. MMPs play an important biological role in regulating the formation, remodeling and degradation of extracellular matrix and participate in various physiological and pathological processes of cells. Bone marrow-derived mesenchymal stem cells (BMSCs) are a kind of pluripotent stem cell which has the ability to self-renew and differentiate into functional cells. Meanwhile, they can respond to the damage signals and migrate to injured site for tissue repair and regeneration. MMPs and their inhibitors TIMPs affect the differentiation and migration of BMSCs. This article reviews the roles of MMPs in differentiation and migration of BMSCs.
Bone Marrow Cells ; cytology ; Cell Differentiation ; physiology ; Cell Movement ; physiology ; Humans ; Matrix Metalloproteinases ; physiology ; Mesenchymal Stromal Cells ; cytology

To elucidate the effect of established primary bone marrow stromal layers on the gene transduction of human hematopoietic stem/progenitor cells (HSC/HPC), mononuclear cells (MNC) from adult bone marrow were isolated by centrifugation on Ficoll-Hypaque gradients and plated in stromal culture medium. The cells were incubated until passage 4 to establish primary stromal layers. The HSC/HPC prestimulated by cytokines were transduced by retroviral supernatant containing mdr1 gene in presence of irradiated stroma-contact support. Transduced cells were plated in a colony-forming unit assay with and without vincristine (VCR) to assess the efficiency of transduction. Individual colonies were also analyzed by polymerase chain reaction (PCR) for the presence of provirus. The results showed that the mixed adherent cell layers were formed when adult bone marrow stromal cells were incubated for four to six weeks, mainly being composed of fibroblasts. In the presence of stroma-contact support, the average of gene transduction efficiency in marrow-derived progenitors increased 2.1 to 3.3 folds measured by colony-forming assay and/or PCR, significantly higher than those without support of stroma. It is concluded that the presence of bone marrow stroma support in combination with cytokine facilitates augmenting the extent of retroviral-mediated gene transduction.
Bone Marrow Cells ; physiology ; Genes, MDR ; Hematopoietic Stem Cells ; metabolism ; Humans ; Retroviridae ; genetics ; Stromal Cells ; physiology ; Transduction, Genetic

BACKGROUNDNowadays bone marrow represents the main source of mesenchymal stem cells (MSCs). We identified a new population of MSCs derived from human placenta and compared its biological characterization with bone marrow derived MSCs.

METHODSMononucleated cells (MNC) were isolated from the human placenta tissue perfusate by density gradient fractionation. Individual colonies were selected and cultured in tissue dishes. At the same time, human bone marrow derived MSCs were identified. Culture-expanded cells were characterized by immune phenotyping and cultured under conditions promoting differentiation to osteoblasts or adipocytes. The hematopoietic cytokines were assayed using reverse transcriptase polymerase chain reaction (RT-PCR).

RESULTSHuman placental MSCs exhibited fibroblastoid morphology. Flow cytometric analyses showed that the placental MSC were CD29, CD44, CD73, CD105, CD166, HLA-ABC positive; but were negative for CD34, CD45, and HLA-DR. Functionally, they could be induced into adipocytes or osteocytes. Moreover, several hematopoietic cytokine mRNA was found in placenta-derived MSCs by RT-PCR analysis, including IL-6, M-CSF, Flt3-ligand and SCF. These results were consistent with the properties of bone marrow derived MSCs.

CONCLUSIONThese observations implicate the postpartum human placenta as an important and novel source of multipotent stem cells that could potentially be used for investigating mesenchymal differentiation and regulation of hematopoiesis.

Bone Marrow Cells ; physiology ; Cell Differentiation ; Cells, Cultured ; Female ; Humans ; Mesenchymal Stromal Cells ; physiology ; Placenta ; cytology ; Pregnancy

Tissue engineering allows the design of functionally active cells within supportive bio-scaffolds to promote the development of new tissues such as cartilage and bone for the restoration of pathologically altered tissues. However, all bone tissue engineering applications are limited by a shortage of stem cells. The adult bone marrow stroma contains a subset of nonhematopoietic cells referred to as bone marrow mesenchymal stem cells (BMSCs). BMSCs are of interest because they are easily isolated from a small aspirate of bone marrow and readily generate single-cell-derived colonies. These cells have the capacity to undergo extensive replication in an undifferentiated state ex vivo. In addition, BMSCs have the potential to develop either in vitro or in vivo into distinct mesenchymal tissues, including bone, cartilage, fat, tendon, muscle, and marrow stroma. Thus, BMSCs are an attractive cell source for tissue engineering approaches. However, BMSCs are not homogeneous and the quantity of stem cells decreases in the bone marrow in aged population. A sequential loss of lineage differentiation potential has been found in the mixed culture of bone marrow stromal cells due to a heterogenous population. Therefore, a number of studies have proposed that homogenous bone marrow stem cells can be generated from clonal culture of bone marrow cells and that BMSC clones have the greatest potential for the application of bone regeneration in vivo.
Adult Stem Cells ; physiology ; Bone Marrow Cells ; physiology ; Bone Regeneration ; physiology ; Cell Culture Techniques ; Cell Differentiation ; physiology ; Cell Lineage ; physiology ; Clone Cells ; physiology ; Humans ; Mesenchymal Stromal Cells ; physiology ; Osteogenesis ; physiology ; Tissue Engineering ; methods