Hypoxic behavior in cells under controlled microfluidic environment

- A model is presented for cells experiencing hypoxia in a microfluidic chip.
- Change in extracellular parameters considerably alters intracellular hypoxic response.
- Control of prolyl hydroxylase domains can be potent in controlling hypoxic response.
- A simplified mathematical model for cellular ascorbate uptake is also proposed.

BackgroundDepleted oxygen levels, known as hypoxia, causes considerable changes in the cellular metabolism. Hypoxia-inducible factors (HIF) act as the major protagonist in orchestrating manifold hypoxic responses by escaping cellular degradation mechanisms. These complex and dynamic intracellular responses are significantly dependent on the extracellular environment. In this study, we present a detailed model of a hypoxic cellular microenvironment in a microfluidic setting involving HIF hydroxylation.MethodsWe have modeled the induction of hypoxia in a microfluidic chip by an unsteady permeation of oxygen from the microchannel through a porous polydimethylsiloxane channel wall. Extracellular and intracellular interactions were modeled with two different mathematical descriptions. Intracellular space is directly coupled to the extracellular environment through uptake and consumption of oxygen and ascorbate similar to cells in vivo.ResultsOur results indicate a sharp switch in HIF hydroxylation behavior with changing prolyl hydroxylase levels from 0.1 to 4.0 μM. Furthermore, we studied the effects of extracellular ascorbate concentration, using a new model, to predict its accumulation inside the cell over a relevant physiological range. In different hypoxic conditions, the cellular environment showed a significant dependence on oxygen levels in resulting intracellular response.ConclusionsChange in hydroxylation behavior and nutrient supplementation can have significant potential in designing novel therapeutic interventions in cancer and ischemia/reperfusion injuries.General significanceThe hybrid mathematical model can effectively predict intracellular behavior due to external influences providing valuable directions in designing future experiments.