Cells Isolated from Cadaveric Bone Marrow are Safe for Use in Bone Healing and Effective at Promoting Osteogenic Re-construction

The efficacy and immune-modulation of mesenchymal stem cells is well documented. The issue of obtaining mesenchymal stem cells without patient risk, extensive intra-operative procedure, cell manipulation or exposure of cells to harmful reagents remains an issue. This study was designed to test the viability, composition and osteogenic potential of cells derived from cadaveric bone marrow by a new process. Vertebral bone from cadavers was collected within 24 hours of death, processed by a new procedure of tumbling and collection, and evaluated for viability, marker expression, cell composition, and inflammatory properties at various stages of the isolation process and following cryopreservation. Viability was excellent in all fractions and at all stages of the study. Cell staining and microscopic observation showed increased erythrocyte content in the first tumble of bone for marrow extraction, as well as gross observation of debris. Cryopreservation favored the preservation of CD45-/CD105+ and GlycoA-/STRO-1+ mesenchymal stem cells at the expense of platelets, red blood cells, white blood cells and neutrophils. The resulting cell solution contains a percentage of mesenchymal stem cells far above that required for immune modulation. A mixed lymphocyte reaction assay showed no inflammatory response to this cell composition. The cells produced and preserved in this manner are viable, should elicit no immune response, suppress recipient immune responses and osteogenically differentiate

Complement C3 Deficiency Attenuates Chronic Hypoxia-Induced Pulmonary Hypertension in Mice

Background: Evidence suggests a role of both innate and adaptive immunity in the development of pulmonary arterial hypertension. The complement system is a key sentry of the innate immune system and bridges innate and adaptive immunity. To date there are no studies addressing a role for the complement system in pulmonary arterial hypertension. Methodology/Principal Findings: Immunofluorescent staining revealed significant C3d deposition in lung sections from IPAH patients and C57Bl6/J wild-type mice exposed to three weeks of chronic hypoxia to induce pulmonary hypertension. Right ventricular systolic pressure and right ventricular hypertrophy were increased in hypoxic vs. normoxic wild-type mice, which were attenuated in C3-/- hypoxic mice. Likewise, pulmonary vascular remodeling was attenuated in the C3-/- mice compared to wild-type mice as determined by the number of muscularized peripheral arterioles and morphometric analysis of vessel wall thickness. The loss of C3 attenuated the increase in interleukin-6 and intracellular adhesion molecule-1 expression in response to chronic hypoxia, but not endothelin-1 levels. In wild-type mice, but not C3-/- mice, chronic hypoxia led to platelet activation as assessed by bleeding time, and flow cytometry of platelets to determine cell surface P-selectin expression. In addition, tissue factor expression and fibrin deposition were increased in the lungs of WT mice in response to chronic hypoxia. These pro-thrombotic effects of hypoxia were abrogated in C3-/- mice. Conclusions: Herein, we provide compelling genetic evidence that the complement system plays a pathophysiologic role in the development of PAH in mice, promoting pulmonary vascular remodeling and a pro-thrombotic phenotype. In addition we demonstrate C3d deposition in IPAH patients suggesting that complement activation plays a role in the development of PAH in humans. © 2011 Bauer et al

The Relationship between Exosomes and Cancer: Implications for Diagnostics and Therapeutics

Exosomes are very small extracellular vesicles secreted by cells to local and distant tissues. These mini signal transporters elicit acute and chronic effects on recipient cells. Studies regarding exosomes and their relationship to disease, as well as healthy functions, are eliciting extraordinary excitement as data pours in from groups around the world. Reporting of exosome biogenesis, selective loading of cargo, directed release, and resulting changes in adjacent and distal cells are providing information that is changing the way we view cancer progression and treatment. As a result, the properties of exosomes are being exploited for diagnostic, prognostic, and therapeutic applications. First, by referring to the signaling molecules carried by exosomes, they are being tested as indicators of the presence of transformed cells in early stages of cancer. Secondly, the cargo of exosomes secreted from tumors have been linked to prognostic factors and metastatic properties. Thirdly, exosome-based therapies are being developed which utilize the inherent properties of these mini-transporters to affect and interfere with cancer. Exosome creation, loading, and release plays an important role in cancer formation, progression and organotropic metastasis. The developed and developing therapies should be considered with understanding of their advantages and pitfalls, as well as the various roles exosomes play in normal and pathogenic processes. The combination of previously discovered attributes of exosomes with new discoveries occurring daily provide valuable and additive relevant factors to be considered as we embark on the continued discovery of exosomes and their relationship to cancer diagnostics and therapeutics