Generation of brown adipose tissue from pluripotent stem cells in vitro
A population of Brown adipose tissue (BAT) cells generated from embryonic stem cells (ES) or induced pluripotent stem cells (iPS), called iBAT, the use thereof, methods to obtain iBAT by directed differentiation of ES/iPS, and media compositions to obtain iBAT.
1. An in vitro method of generating an induced Brown Adipose Tissue (iBAT) cell, the method comprising:
providing a paraxial mesoderm (PAM) cell that expresses at least one of pair box gene 3 (Pax3), myogenic factor 5 (Myf5), and pair box gene 7 (Pax7);
culturing the PAM cell in conditions comprising:
(i) medium comprising effective amounts of each of an hepatocyte growth factor (HGF) signaling pathway activator, an insulin-like growth factor (IGF) signaling pathway activator, a fibroblast growth factor (FGF) signaling pathway activator, and a bone morphogenetic (BMP) signaling pathway inhibitor for at least one day, followed by culturing in a medium comprising an HGF signaling pathway activator and an IGF signaling pathway activator but lacking a FGF signaling pathway activator; or
(ii) medium comprising an FGF signaling pathway inhibitor and a Retinoic acid signaling pathway activator for two to six days, followed by an adipocyte differentiation medium;
under conditions and for a time sufficient for the cells to differentiate into iBAT cells that express uncoupling protein 1 (UCP-1).
2. The method of claim 1 , wherein the adipocyte differentiation medium comprises a serum replacement supplement; Insulin-Transferin-Selenium; isobutylmethylxanthine (IBMX); indomethacin, triiodothreonine (T3); dexamethasone; and rosiglitazone.
3. The method of claim 1 , wherein the iBAT cell is a multilocular fat cell with a dark or brown coloration in brightfield imaging; adherent or in suspension; has circular compacted nuclei; is enriched for mitochondria; and is enriched in lipid droplets of various sizes ranging from 0.1 μm2 to 1000 μm2 in surface area according to a rectilinear parallel projection, or ranging from 1 μm3 to thousands of μm3 in volume.
4. The method of claim 1 , wherein an iBAT cell generated according to condition (i) of claim 1 comprises numerous lipid droplets of sizes ranging from 0.5 μm2 to 1000 μm2 in surface area according to a rectilinear parallel projection, or ranging from 5 μm3 to 10,000 of μm3 in volume.
5. The method of claim 1 , wherein an iBAT cell generated according to condition (ii) of claim 1 contains numerous lipid droplets of sizes ranging from 0.1 μm2 to 50 μm2 in surface area according to a rectilinear parallel projection, or ranging from 1 μm3 to 100 μm3 in volume.
6. The method of claim 1 , further comprising culturing the iBAT cells under conditions sufficient for proliferation to occur.