Method for producing naïve pluripotent stem cells

Abstract

To produce and/or maintain naïve pluripotent stem cells capable of highly expressing genes important for maintaining an undifferentiated state, which could not be achieved by known methods for producing pluripotent stem cells. The present invention can produce naïve pluripotent stem cells capable of maintaining an undifferentiated state by introducing and allowing transient expression of six genes (Oct3/4, Klf4, c-Myc, Sox2, Nanog, and Klf2) among the so-called initializing factors, and further performing culturing in a medium containing LIF, an MEK inhibitor, a GSK3 inhibitor, a cAMP production promoter, a TGF-β inhibitor and a PKC inhibitor. Thus, the problem of the present invention can be solved.

1 . A method for producing a naïve induced pluripotent stem cell, comprising allowing transient expression of the following six genes: Nanog, Klf2, Oct3/4, Klf4, c-Myc, and Sox2 in a somatic cell. 
     
     
         2 . The method for producing a naïve induced pluripotent stem cell according to  claim 1 , further comprising performing culturing in a medium containing LIF, an MEK inhibitor, a GSK3 inhibitor, a cAMP production promoter, a TGF-β inhibitor and a PKC inhibitor. 
     
     
         3 . The method for producing a naïve induced pluripotent stem cell according to  claim 1 , wherein the somatic cell is a human-derived somatic cell. 
     
     
         4 . The method for producing a naïve induced pluripotent stem cell according to  claim 2 , wherein the MEK inhibitor is PD0325901, the GSK3 inhibitor is CHIR99021, the cAMP production promoter is Forskolin, the TGF-β inhibitor is A83-01, and the PKC inhibitor is Go6983. 
     
     
         5 . The method for producing a naïve induced pluripotent stem cell according to  claim 2 , wherein the medium is an N2B27 medium. 
     
     
         6 . A method for maintaining a naïve pluripotent stem cell, comprising culturing the naïve pluripotent stem cell in a medium containing LIF, an MEK inhibitor, a GSK3 inhibitor, a cAMP production promoter, a TGF-β inhibitor and a PKC inhibitor. 
     
     
         7 . The method for maintaining a naïve pluripotent stem cell according to  claim 6 , wherein the naïve pluripotent stem cell is a naïve induced pluripotent stem cell or a naïve embryonic stem cell. 
     
     
         8 . The method for maintaining a naïve pluripotent stem cell according to  claim 6 , wherein the naïve pluripotent stem cell is a naïve human induced pluripotent stem cell or a naïve human embryonic stem cell. 
     
     
         9 . The method for maintaining a naïve pluripotent stem cell according to  claim 6 , wherein the naïve pluripotent stem cell is a naïve human induced pluripotent stem cell. 
     
     
         10 . The method for maintaining a naïve pluripotent stem cell according to  claim 6 , wherein the MEK inhibitor is PD0325901, the GSK3 inhibitor is CHIR99021, the cAMP production promoter is Forskolin, the TGF-β inhibitor is A83-01, and the PKC inhibitor is Go6983. 
     
     
         11 . The method for maintaining a naïve pluripotent stem cell according to  claim 6 , wherein the medium is an N2B27 medium.