Fig. 6.

Alcohol injury in microfluidic hepatocyte spheroid cultures. A: a representative microfluidic cell culture device outfitted with polydimethylsiloxane caps to prevent evaporation of ethanol (EtOH) and culture media. B and C: expression of alcohol dehydrogenase (ADH)1 and cytochrome P450 2E1 (CYP2E1), enzymes responsible for alcohol metabolism, was measured by RT-PCR. These enzymes were expressed at high basal level in microfluidic spheroid (3D) cultures compared with tissue culture polystyrene (TCPS). Induction of these enzymes was observed in the presence of EtOH in microfluidic cultures. Welch’s t test was used to establish statistical significance for both ADH1 and CYP2E1 expression. D and E: scanned electron images showing topography of uninjured spheroids (D) and those exposed to alcohol (E). Scale bar: 5 µm. F: caspase activity assay used to assess apoptosis in standard TCPS cultureware and in small-volume spheroid cultures of hepatocytes exposed to 100 mM EtOH. Treatment with 10 ng/mL IL-22 protects hepatocytes against apoptosis. Mann–Whitney test was used to determine statistical significance. *P < 0.05.