Effects of long-term hypoxia and pro-survival cocktail in bone marrow-derived stromal cell survival.

The goal of this study was to determine whether a pro-survival cocktail (PSC, consisting of IGF-1, Bcl-XL, and Caspase-I Inhibitor) and long-term hypoxia (LTH) enhance survival and functional properties of bone marrow-derived stromal stem cells (BMSCs), in response to stress conditions. PSC-treated cells retained BMSC surface markers and protected cells from apoptosis under serum starvation and ischemic (1% O2 and 100 μM H2O2) conditions. LTH promoted osteogenesis, while suppressing adipogenesis.

Enhanced homing permeability and retention of bone marrow stromal cells by noninvasive pulsed focused ultrasound.

Bone marrow stromal cells (BMSCs) have shown significant promise in the treatment of disease, but their therapeutic efficacy is often limited by inefficient homing of systemically administered cells, which results in low number of cells accumulating at sites of pathology. BMSC home to areas of inflammation where local expression of integrins and chemokine gradients is present. We demonstrated that nondestructive pulsed focused ultrasound (pFUS) exposures that emphasize the mechanical effects of ultrasound-tissue interactions induced local and transient elevations of chemoattractants (i.

Self-assembling nanocomplexes by combining ferumoxytol, heparin and protamine for cell tracking by magnetic resonance imaging.

We report on a new straightforward magnetic cell-labeling approach that combines three US Food and Drug Administration (FDA)-approved drugs--ferumoxytol, heparin and protamine--in serum-free medium to form self-assembling nanocomplexes that effectively label cells for in vivo magnetic resonance imaging (MRI). We observed that the ferumoxytol-heparin-protamine (HPF) nanocomplexes were stable in serum-free cell culture medium. HPF nanocomplexes show a threefold increase in T2 relaxivity compared to ferumoxytol.

Investigation of cellular and molecular responses to pulsed focused ultrasound in a mouse model.

Continuous focused ultrasound (cFUS) has been widely used for thermal ablation of tissues, relying on continuous exposures to generate temperatures necessary to induce coagulative necrosis. Pulsed FUS (pFUS) employs non-continuous exposures that lower the rate of energy deposition and allow cooling to occur between pulses, thereby minimizing thermal effects and emphasizing effects created by non-thermal mechanisms of FUS (i.e.

Circulating CD133+CD34+ progenitor cells inversely correlate with soluble ICAM-1 in early ischemic stroke patients.

Background And Purpose: Both endothelial progenitor cells (EPC) and markers of neuroinflammation are candidate biomarkers for stroke severity and outcome prediction. A relationship between EPC and neuroinflammatory markers in early stroke is not fully elucidated. The objectives were to investigate correlations between EPC and neuroinflammation markers (adhesion molecules ICAM-1, VCAM-1, E-selectin, tumor necrosis factor (TNF)-α, interleukin (IL)-6, endothelin (ET)-1, markers of tissue injury (matrix metalloproteinases (MMP)-9 and tissue inhibitor of matrix metalloproteinases (TIMP)-1) in early stroke patients.

Sigma-2 receptor as potential indicator of stem cell differentiation.

Purpose: The sigma-2 (σ(2)) receptor is a potential biomarker of proliferative status of solid tumors. Specific synthetic probes using N-substituted-9-azabicyclo [3.3.

Stromal-derived factor-1[alpha] correlates with circulating endothelial progenitor cells and with acute lesion volume in stroke patients.

Background And Purpose: Endothelial progenitor cells (EPC) are important participants of neovascularization and are mobilized through signaling with stromal-derived factor (SDF-1α), vascular endothelial growth factor (VEGF), granulocyte colony-stimulating factor, and stem cell factor. The association between EPC levels and these growth factors (GF) in acute stroke has not been previously established. We aimed to determine the association between EPC and these GF, and to elucidate a relationship between these GF and stroke severity in acute stroke patients.

Superparamagnetic iron oxide nanoparticles labeling of bone marrow stromal (mesenchymal) cells does not affect their "stemness".

Superparamagnetic iron oxide nanoparticles (SPION) are increasingly used to label human bone marrow stromal cells (BMSCs, also called "mesenchymal stem cells") to monitor their fate by in vivo MRI, and by histology after Prussian blue (PB) staining. SPION-labeling appears to be safe as assessed by in vitro differentiation of BMSCs, however, we chose to resolve the question of the effect of labeling on maintaining the "stemness" of cells within the BMSC population in vivo. Assays performed include colony forming efficiency, CD146 expression, gene expression profiling, and the "gold standard" of evaluating bone and myelosupportive stroma formation in vivo in immuncompromised recipients.

In vivo transfer of intracellular labels from locally implanted bone marrow stromal cells to resident tissue macrophages.

Intracellular labels such as dextran coated superparamagnetic iron oxide nanoparticles (SPION), bromodeoxyuridine (BrdU) or green fluorescent protein (GFP) are frequently used to study the fate of transplanted cells by in vivo magnetic resonance imaging or fluorescent microscopy. Bystander uptake of labeled cells by resident tissue macrophages (TM) can confound the interpretation of the presence of intracellular labels especially during direct implantation of cells, which can result in more than 70% cell death. In this study we determined the percentages of TM that took up SPION, BrdU or GFP from labeled bone marrow stromal cells (BMSCs) that were placed into areas of angiogenesis and inflammation in a mouse model known as Matrigel plaque perfusion assay.

In vitro model of bromodeoxyuridine or iron oxide nanoparticle uptake by activated macrophages from labeled stem cells: implications for cellular therapy.

There is increasing interest in using exogenous labels such as bromodeoxyuridine (BrdU) or superparamagnetic iron oxide nanoparticles (SPION) to label cells to identify transplanted cells and monitor their migration by fluorescent microscopy or in vivo magnetic resonance imaging (MRI), respectively. Direct implantation of cells into target tissue can result in >80% cell death due to trauma or apoptosis. Bystander uptake of labeled cells by activated macrophages (AM) can confound the interpretation of results.

Cyclopamine-mediated hedgehog pathway inhibition depletes stem-like cancer cells in glioblastoma.

Brain tumors can arise following deregulation of signaling pathways normally activated during brain development and may derive from neural stem cells. Given the requirement for Hedgehog in non-neoplastic stem cells, we investigated whether Hedgehog blockade could target the stem-like population in glioblastoma multiforme (GBM). We found that Gli1, a key Hedgehog pathway target, was highly expressed in 5 of 19 primary GBM and in 4 of 7 GBM cell lines.

Hedgehog signaling promotes medulloblastoma survival via Bc/II.

Activation of the Hedgehog (Hh) pathway has been identified in several cancers, including medulloblastoma, but the mechanisms by which this pathway affects tumor survival and growth are incompletely understood. We investigated whether Hedgehog might promote survival of medulloblastoma cells via up-regulation of BclII. We found that mRNA levels of the Hedgehog pathway effector Gli1 were significantly associated with BclII expression in medulloblastoma and that Gli1 and BclII are both present in regions of decreased apoptosis in nodular medulloblastoma.

c-myc overexpression causes anaplasia in medulloblastoma.

Both anaplasia and increased c-myc gene expression have been shown to be negative prognostic indicators for survival in medulloblastoma patients. myc gene amplification has been identified in many large cell/anaplastic medulloblastoma, but no causative link between c-myc and anaplastic changes has been established. To address this, we stably overexpressed c-myc in two medulloblastoma cell lines, DAOY and UW228, and examined the changes in growth characteristics.

Increased p53 immunopositivity in anaplastic medulloblastoma and supratentorial PNET is not caused by JC virus.

Background: p53 mutations are relatively uncommon in medulloblastoma, but abnormalities in this cell cycle pathway have been associated with anaplasia and worse clinical outcomes. We correlated p53 protein expression with pathological subtype and clinical outcome in 75 embryonal brain tumors. The presence of JC virus, which results in p53 protein accumulation, was also examined.

Retina-specific expression of PDGF-B versus PDGF-A: vascular versus nonvascular proliferative retinopathy.

Purpose: Platelet-derived growth factor (PDGF) has been implicated in vascular proliferative retinopathies, such as diabetic retinopathy, and in nonvascular retinopathies, such as proliferative vitreoretinopathy. Traction retinal detachment is a central feature of both types of disease. Hemizygous rhodopsin promoter/PDGF-B (rho/PDGF-B) transgenic mice exhibit proliferation of vascular cells, glia, and retinal pigmented epithelial (RPE) cells, resulting in traction retinal detachment.