High glucose increase cell cycle regulatory proteins level of mouse embryonic stem cells via PI3-K/Akt and MAPKs signal pathways.

This study examined the effects of high glucose on cell proliferation and its related signal pathways using mouse embryonic stem (ES) cells. Here, we showed that high glucose level significantly increased [3H]thymidine incorporation, BrdU incorporation, the number of cells, [3H]leucine, and [3H]proline incorporation in a time-( >3 hr) and dose-(> 25 mM) dependent manner. Moreover, high glucose level increased the cellular reactive oxygen species (ROS), Akt, and mitogen-activated protein kinases (MAPKs) phosphorylation. Subsequently, these signaling molecules involved in high glucose-induced increase of [3H]thymidine incorporation. High glucose level also increased cyclin D1, cyclin E, cyclin-dependent kinase (CDK) 2, and CDK 4 protein levels, which is cell cycle regulatory proteins acting in G1-S phase of cell cycle. Inhibition of phosphatidylinositol 3-kinase (PI3-K) (LY 294002: PI3-kinase inhibitor, 10(-6) M), Akt (Akt inhibitor, 10(-5) M), and p44/42 MAPKs (PD 98059: MEK inhibitor, 10(-5) M) decreased these proteins. High glucose level phosphorylated the RB protein, which was decreased by inhibition of PI3-K and Akt. In conclusion, high glucose level stimulates mouse ES cell proliferation via the PI3-K/Akt and MAPKs pathways.

Kim YH ，Heo JS ，Han HJ 《JOURNAL OF CELLULAR PHYSIOLOGY》

High glucose regulates cyclin D1/E of human mesenchymal stem cells through TGF-beta1 expression via Ca2+/PKC/MAPKs and PI3K/Akt/mTOR signal pathways.

The elucidation of factors that support human mesenchymal stem cells (hMSCs) growth has remained unresolved partly because of the reliance of many researchers on ill-defined, proprietary medium formulation. Thus, we investigated the effects of high glucose (D-glucose, 25 mM) on hMSCs proliferation. High glucose significantly increased [(3)H]-thymidine incorporation and cell-cycle regulatory protein expression levels compared with 5 mM D-glucose or 25 mM L-glucose. In addition, high glucose increased transforming growth factor-beta1 (TGF-beta(1)) mRNA and protein expression levels. High glucose-induced cell-cycle regulatory protein expression levels and [(3)H]-thymidine incorporation, which were inhibited by TGF-beta(1) siRNA transfection and TGF-beta(1) neutralizing antibody treatment. High glucose-induced phosphorylation of protein kinase C (PKC), p44/42 mitogen-activated protein kinases (MAPKs), p38 MAPK, Akt, and mammalian target of rapamycin (mTOR) in a time-dependent manner. Pretreatment of PKC inhibitors (staurosporine, 10(-6) M; bisindolylmaleimide I, 10(-6) M), LY 294002 (PI3 kinase inhibitor, 10(-6) M), Akt inhibitor (10(-5) M), PD 98059 (p44/42 MAPKs inhibitor, 10(-5) M), SB 203580 (p38 MAPK inhibitor, 10(-6) M), and rapamycin (mTOR inhibitor, 10(-8) M) blocked the high glucose-induced cellular proliferation and TGF-beta(1) protein expression. In conclusion, high glucose stimulated hMSCs proliferation through TGF-beta(1) expression via Ca(2+)/PKC/MAPKs as well as PI3K/Akt/mTOR signal pathways.

Ryu JM ，Lee MY ，Yun SP ，Han HJ ... -  《-》

ATP stimulates mouse embryonic stem cell proliferation via protein kinase C, phosphatidylinositol 3-kinase/Akt, and mitogen-activated protein kinase signaling pathways.

Heo JS ，Han HJ 《STEM CELLS》

Zinc chloride stimulates DNA synthesis of mouse embryonic stem cells: involvement of PI3K/Akt, MAPKs, and mTOR.

Ryu JM ，Lee MY ，Yun SP ，Han HJ ... -  《-》

High glucose induced translocation of Aquaporin8 to chicken hepatocyte plasma membrane: involvement of cAMP, PI3K/Akt, PKC, MAPKs, and microtubule.

Suh HN ，Lee SH ，Lee MY ，Heo JS ，Lee YJ ，Han HJ ... -  《-》