In vitro metabolic activation of vitamin D3 by using a multi-compartment microfluidic liver-kidney organ on chip platform

Sci Rep. 2019 Mar 15;9(1):4616. doi: 10.1038/s41598-019-40851-9.


Organ-on-chip platforms provide models that allow the representation of human physiological processes in cell-based miniaturized systems. Potential pre-clinical applications include drug testing and toxicity studies. Here we describe the use of a multi-compartment micro-fluidic chip to recapitulate hepatic vitamin D metabolism (vitamin D to 25-hydroxyvitamin D) and renal bio-activation (25-hydroxyvitamin D to 1,25-dihydroxyvitamin D) in humans. In contrast to cultivation in conventional tissue culture settings, on-chip cultivation of HepG2 and RPTEC cells in interconnected chambers, used to mimic the liver and kidneys, respectively, resulted in the enhanced expression of vitamin D metabolizing enzymes (CYP2R1, CYP27B1 and CYP24A1). Pump-driven flow of vitamin D3-containing medium through the microfluidic chip produced eluate containing vitamin D3 metabolites. LC-MSMS showed a strong accumulation of 25-hydroxyvitamin D. The chip eluate induced the expression of differentiation markers in HL-60 (acute myeloid leukemia) cells, assessed by qPCR and FACS analysis, in a manner similar to treatment with reference standards indicating the presence of fully activated 1,25 dihydroxyvitamin D, although the latter was not detected in the eluate by LC-MSMS. Interestingly, 25-hydroxyvitamin D by itself led to weak activation of HL-60 cells suggesting that 25-hydroxyvitamin D is also an active metabolite. Our experiments demonstrate that complex metabolic interactions can be reconstructed outside the human body using dedicated organ-on-chip platforms. We therefore propose that such systems may be used to mimic the in vivo metabolism of various micronutrients and xenobiotics.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 25-Hydroxyvitamin D3 1-alpha-Hydroxylase / metabolism
  • Activation, Metabolic / physiology
  • Animals
  • Cell Line
  • Cholecalciferol / metabolism*
  • Cytochrome P-450 Enzyme System / metabolism
  • HL-60 Cells
  • Hep G2 Cells
  • Humans
  • Kidney / metabolism*
  • Lab-On-A-Chip Devices
  • Liver / metabolism*
  • Microchip Analytical Procedures / methods
  • Microfluidic Analytical Techniques / methods
  • Microfluidics / methods
  • Vitamin D / analogs & derivatives
  • Vitamin D / metabolism
  • Vitamins / metabolism


  • Vitamins
  • Vitamin D
  • Cholecalciferol
  • Cytochrome P-450 Enzyme System
  • 25-hydroxyvitamin D
  • 25-Hydroxyvitamin D3 1-alpha-Hydroxylase