1 research outputs found
Effect of Microculture on Cell Metabolism and Biochemistry: Do Cells Get Stressed in Microchannels?
Microfluidics is emerging as a promising platform for
cell culture,
enabling increased microenvironment control and potential for integrated
analysis compared to conventional macroculture systems such as well
plates and Petri dishes. To advance the use of microfluidic devices
for cell culture, it is necessary to better understand how miniaturization
affects cell behavior. In particular, microfluidic devices have significantly
higher surface-area-to-volume ratios than conventional platforms,
resulting in lower volumes of media per cell, which can lead to cell
stress. We investigated cell stress under a variety of culture conditions
using three cell lines: parental HEK (human embryonic kidney) cells
and transfected HEK cells that stably express wild-type (WT) and mutant
(G601S) <i>human ether-a-go-go related gene</i> (hERG) potassium
channel protein. These three cell lines provide a unique model system
through which to study cell-type-specific responses in microculture
because mutant hERG is known to be sensitive to environmental conditions,
making its expression a particularly sensitive readout through which
to compare macro- and microculture. While expression of WT-hERG was
similar in microchannel and well culture, the expression of mutant
G601S-hERG was reduced in microchannels. Expression of the endoplasmic
reticulum (ER) stress marker immunoglobulin binding protein (BiP)
was upregulated in all three cell lines in microculture. Using BiP
expression, glucose consumption, and lactate accumulation as readouts
we developed methods for reducing ER stress including properly increasing
the frequency of media replacement, reducing cell seeding density,
and adjusting the serum concentration and buffering capacity of culture
medium. Indeed, increasing the buffering capacity of culture medium
or frequency of media replacement partially restored the expression
of the G601S-hERG in microculture. This work illuminates how biochemical
properties of cells differ in macro- and microculture and suggests
strategies that can be used to modify cell culture protocols for future
studies involving miniaturized culture platforms