Methods for amplifying and differentiating pancreatic cells, and application thereof
An amplifying method of pancreatic cells is provided. The amplifying method includes performing digestion, resuspension, discontinuous density gradient centrifugation treatment and amplifying treatment sequentially. The mammalian pancreatic duct is used as the source of pancreatic precursor-like cells in the amplifying method, and islet cells and acinar cells in the cell clusters obtained by the discontinuous density gradient centrifugation treatment are removed. It is beneficial to improve the yield of the pancreatic precursor-like cells availably, and avoid the ethical restrictions and possible carcinogenic risks caused by using the embryonic stem cells. The amplifying medium used comprises a reprogramming substance composed of several small molecule compounds. It can avoid the risks of non-specific and off-target deletion that are easily caused by the use of the gene-editing methods to change the gene sequence. Also provided is a differentiation method and an application of the pancreatic precursor-like cells obtained by the amplifying method.
1 . An amplifying method of pancreatic cells, comprising:
S1: obtaining pancreatic tissue, derived from a mammalian pancreatic duct;
S2: performing digestion, resuspension, and discontinuous density gradient centrifugation treatment to the pancreatic tissue in sequence, collecting the cell clusters at each density gradient junction, and then removing islet cells and acinar cells in the cell clusters to obtain primary cells;
S3: performing an amplifying and adhering treatment to the primary cells with an amplifying medium to induce reprogramming of the primary cells to obtain pancreatic precursor-like cells;
wherein a period of the amplifying treatment was at least 72 hours, and the amplifying medium was replaced every 48 hours after the cells are adhered to a culture dish by the adhering treatment;
wherein the amplifying medium comprising a reprogramming substance composed of several small molecule compounds, and the reprogramming substance comprises growth factor, Rock signal pathway inhibitor, WNT signal pathway agonist and TGF-β signal pathway inhibitor,
in the step S2, at least three demixing agents with different densities are used to perform the discontinuous density gradient centrifugation treatment, the adjacent demixing agents are a low-density demixing agent and a high-density stratification, and the density of the low-density demixing agent is decreased by 0.1-3% relative to the density of the high-density demixing agent, and wherein
the highest density of the demixing agents is not higher than 1.1 g/ml, and the lowest density of the demixing agents is not less than 1.03 g/ml;
wherein the pancreatic precursor like cells are formed in a single cell layer by adhering to the culture dish in the adhering treatment, and the pancreatic precursor like cells of the single cell layer can be proliferated until the 10th generation and be still in an exponential growth phase.
2 . The amplifying method of claim 1 , wherein the pancreatic tissue is derived from a human pancreatic duct.
3 . The amplifying method of claim 1 , wherein the growth factor comprises at least one of epidermal growth factor, hepatocyte growth factor, and fibroblast growth factor, wherein a content of any one of the epidermal growth factor, the hepatocyte growth factor, and the fibroblast growth factor is 5-100 ng/ml in the amplifying medium.
4 . The amplifying method of claim 1 , wherein a content of the Rock signal pathway inhibitor is 2-15 μmol/L, a content of the WNT signal pathway agonist is 2-10 μmol/L, and a content of the TGF-β signal pathway inhibitor is 0.5-20 μmol/L in the amplifying medium.
5 . The amplifying method of claim 4 , wherein the Rock signal pathway inhibitor is at least one of Y27632, Fasudil, Thiazovivin, and SB-772077-B; the WNT signal pathway agonist is at least one of recombinant WNT protein, recombinant R-spondin protein, and glycogen synthase kinase 3β inhibitor; the glycogen synthase kinase 3β inhibitor is at least one of BIO, CHIR99021, and TWS119; the TGF-β signal pathway inhibitor is at least one of A83-01, RepSox, and SB431542.
6 . The amplifying method of claim 1 , wherein the amplifying medium further comprises a basic medium, serum, and serum-free neuron supplement; in the amplifying medium, the total volume of the serum and the serum-free neuron supplement is not higher than 15%, and the volume percentage of the serum is 2% to 10%.
7 . The amplifying method of claim 6 , wherein the reprogramming substance further comprise a lipid signal substance having a content of 0.5-10 μmol/L in the amplifying medium.
8 . The amplifying method of claim 7 , wherein the lipid signal substance is at least one of sphingosine-1-phosphate and lysophosphatidic acid.
9 . The amplifying method of claim 6 , wherein the basic medium is at least one of MEM, DMEM, BME, DMEM/F12, RPMI1640, CMRL1066, WilliamE, Neurobasal, and Fischers medium; the serum is fetal bovine serum; and the serum-free neuron supplement is at least one of N2 supplement and B27 supplement.