posted on 2018-03-29, 00:00authored bySebastian Martewicz, Giulia Gabrel, Marika Campesan, Marcella Canton, Fabio Di Lisa, Nicola Elvassore
Analyses of cellular responses to
fast oxygen dynamics are challenging
and require ad hoc technological solutions, especially when decoupling
from liquid media composition is required. In this work, we present
a microfluidic device specifically designed for culture analyses with
high resolution and magnification objectives, providing full optical
access to the cell culture chamber. This feature allows fluorescence-based
assays, photoactivated surface chemistry, and live cell imaging under
tightly controlled pO2 environments. The device has a simple
design, accommodates three independent cell cultures, and can be employed
by users with basic cell culture training in studies requiring fast
oxygen dynamics, defined media composition, and in-line data acquisition
with optical molecular probes. We apply this technology to produce
an oxygen/glucose deprived (OGD) environment and analyze cell mortality
in murine and human cardiac cultures. Neonatal rat ventricular cardiomyocytes
show an OGD time-dependent sensitivity, resulting in a robust and
reproducible 66 ± 5% death rate after 3 h of stress. Applying
an equivalent stress to human induced pluripotent stem cell-derived
cardiomyocytes (hiPS-CMs) provides direct experimental evidence for
fetal-like OGD-resistant phenotype. Investigation on the nature of
such phenotype exposed large glycogen deposits. We propose a culture
strategy aimed at depleting these intracellular energy stores and
concurrently activate positive regulation of aerobic metabolic molecular
markers. The observed process, however, is not sufficient to induce
an OGD-sensitive phenotype in hiPS-CMs, highlighting defective development
of mature aerobic metabolism in vitro.