In this issue

Proliferation and Death Through Generations

Akbarian, Wang, and Audet describe an experimental and computational approach to perform quantitative carboxyfluorescein diacetate succinimidyl ester (CFSE) cell-division tracking in cultures of red blood cell progenitors. They used a dynamic model of proliferation based on the Smith-Martin representation of the cell cycle to extract proliferation rates and death rates from CFSE time-series. They found that generation-specific rate parameters were necessary to accurately represent the cell population dynamics. The generation-specific rates of proliferation and death were extracted for 6 generations and they revealed that, although stem cell factor (SCF) alone or erythropoietin (EPO) alone supported similar total cell outputs in culture, stimulation with EPO resulted in significantly higher proliferation rates and higher death rates in most cell generations compared with SCF. This study highlights the usefulness of CFSE cell-division tracking in the development of new erythropoiesis-stimulating agents for in vitro and in vivo use.

In this issue, page 382

Cellular interactions in human vasculature ex vivo

The importance of the interplay between vascular endothelium, mechanical forces and circulating blood components in cardiovascular disease is well established, but current in vitro models utilizing isolated human cells in static culture fail to address the complexity. In order to develop a more physiological model, Holtom and coworkers developed an ex vivo co-culture model using human whole blood as the perfusate through intact inflamed human umbilical artery at arterial flow rate, and used this to investigate microparticle production from each of the interacting cell types, by flow cytometry. They demonstrated that the combination of flow and presence of an inflamed endothelium lead to significantly increased production of microparticles from both platelet and non-platelet sources, and furthermore, they induced significantly enhanced levels of reactive oxygen species, known to contribute to vascular dysfunction. This system provides a highly tractable model to study cellular interactions in human vasculature ex vivo.

In this issue: page 390

Flow cytometric analysis for ischemic brain tissues

Histologic assessment in experimental stroke is dominated by the use of traditional brain sections staining for the damage to neuronal perikarya and labeling for DNA breaks. It is challenging to use flow cytometric examinations to define necrotic and apoptotic cell deaths following ischemic brain damage because a large amount of non-cellular (infarct) tissue debris needs to be removed prior to the FC analysis. Juan and coworkers demonstrate the application of flow cytometry to detect the extent and maturation as well as relative phenotypes of apoptotic/necrotic brain damage. They found that neurons were more vulnerable to apoptosis than glia, whereas both cellular phenotypes were compatible in their susceptibility to necrotic cell death. The authors highlighted the use of Percoll at low percentages so as to facilitate the removal of tissue debris and to improve membrane integrity preservation for the injured neurons.

In this issue: page 400