Cellular observations enabled by microculture: paracrine signaling and population demographics

Abstract

The cellular microenvironment plays a critical role in shaping and directing the process of communication between the cells. Soluble signals are responsible for many cellular behaviors such as cell survival, proliferation and differentiation. Despite the importance of soluble signals, canonical methods are not well suited to the study of soluble factor interactions between multiple cell types. Macro-scale technology often puts cells into a convective environment that can wash away and dilute soluble signals from their targets, minimizing local concentrations of important factors. In addition, current methods such as transwells, require large numbers of cells and are limited to studying just two cell types. Here, we present data supporting the use of microchannels to study soluble factor signaling providing improved sensitivity as well as the ability to move beyond existing co-culture and conditioned medium paradigms. In addition, we present data suggesting that microculture can be used to unmask effects of population demographics. In this example the data support the hypothesis that a growth promoting subpopulation of cells exists in the mouse mammary gland.

Expanding the Available Assays: Adapting and Validating In-Cell Westerns in Microfluidic Devices for Cell-Based Assays

“…The possibility to perform assays in more complex microenvironments such as in gradients of soluble factors or in a coculture with multiple cell types could potentially expand our ability to study how cells respond to stimuli and environments beyond what is currently possible using traditional techniques. [2][3][4][5][6][7][8] While the designs and functionalities of microfluidic devices are diverse, methods for analysis of cellular responses to microenvironments and experimental conditions are not as numerous. One issue that prevents microfluidic assays from being integrated as a tool for in vitro assays, which this article aims to address, is the lack of simple, quantitative readouts.…”

Cellular Microenvironment Dictates Androgen Production by Murine Fetal Leydig Cells in Primary Culture1

“…Transwell systems are not always optimal for co-culture because soluble factors are diluted in relatively large culture volumes. In contrast, microfluidic co-culture methods offer increased sensitivity over transwell systems due to higher surface area-to-volume ratios and reduced diffusion distances between culture compartments [29,30]. Importantly, here we also demonstrated an additional advantage of microco-culture in the ability to design culture compartments with surface areas tuned to reflect the relative proportion of fetal Leydig cells and supporting cells.…”

“…To overcome the problem of working with a small population of cells, we developed microfluidic devices that enabled high cell density culture conditions. A key feature of the platform was the ability to compartmentalize small populations of cells in controlled microenvironments that could better reflect physiological conditions and enable cell-cell interaction studies [29,30]. Microchannel culture is also well suited for studying steroidogenesis [31].…”

On‐chip integrated labelling, transport and detection of tumour cells

“…The overall Electrophoresis 2011, 32, 3188-3195 mobility of these cells showed no difference from that observed in initial experiments characterising the flow system with the K562 cell line. Agarose hydrogel is mechanically similar to ECM and supports the cells in motion, preventing settling out, while permitting continued paracrine interactions via soluble signalling factors [18,47,48].…”