Fibronectin synthesis by high glucose level mediated proliferation of mouse embryonic stem cells: Involvement of ANG II and TGF-beta1.
The role of individual supplements necessary for the long-term self-renewal of embryonic stem (ES) cells is poorly characterized in feeder/serum-free culture systems. This study sought to characterize the relationship between the effects of glucose on ES cell proliferation and fibronectin (FN) synthesis, and to assess the mechanisms responsible for these cellular effects of glucose. Treatment of the two ES cells (ES-E14TG2a and ES-R1) with 25 mM glucose (high glucose) increased the expression levels of FN mRNA and protein. In addition, high glucose and ANG II synergistically increased FN expression level, which coincident with data showing that high glucose increased the mRNA expression of angiotensin II (ANG II) type 1 receptor (AT(1)R), angiotensinogen, and FN, but not ANG II type 2 receptor. High glucose also increased the intracellular calcium (Ca(2+)) concentration and pan-protein kinase C (PKC) phosphorylation. Inhibition of the Ca(2+)/PKC pathway blocked high glucose-induced FN expression. High glucose or ANG II also synergistically increased transforming growth factor-beta1 (TGF-beta(1)) expression, while pretreatment with losartan abolished the high glucose-induced increase in TGF-beta(1) production. Moreover, TGF-beta(1)-specific small interfering RNA inhibited high glucose-induced FN expression and c-Jun N-terminal kinase (JNK) activation. The JNK inhibitor SP600125 blocked high glucose-induced FN expression and inhibited cell cycle regulatory protein expression induced by high glucose or TGF-beta(1). In this study, inhibition of AT(1)R, Ca(2+)/PKC, TGF-beta(1), JNK, FN receptor blocked the high glucose-induced DNA synthesis, increased the cell population in S phase, and the number of cells. It is concluded that high glucose increases FN synthesis through the ANG II or TGF-beta1 pathways, which in part mediates proliferation of mouse ES cells.
Kim
Yun Hee
YH
Department of Veterinary Physiology, Biotherapy Human Resources Center (BK 21), College of Veterinary Medicine, Chonnam National University, Gwangju 500-757, Korea.
Ryu
Jung Min
JM
Lee
Yu Jin
YJ
Han
Ho Jae
HJ
D000804:Angiotensin II / Q000378:metabolism* / Q000494:pharmacology; D047228:Angiotensin II Type 1 Receptor Blockers / Q000494:pharmacology; D000808:Angiotensinogen / Q000235:genetics; D000818:Animals; D020013:Calcium Signaling / Q000187:drug effects / Q000502:physiology; D002452:Cell Count; D049109:Cell Proliferation / Q000187:drug effects*; D004261:DNA Replication / Q000187:drug effects / Q000235:genetics; D053595:Embryonic Stem Cells / Q000187:drug effects / Q000378:metabolism*; D005353:Fibronectins / Q000096:biosynthesis* / Q000187:drug effects / Q000235:genetics; D005947:Glucose / Q000378:metabolism* / Q000494:pharmacology; D006943:Hyperglycemia / Q000235:genetics / Q000378:metabolism / Q000503:physiopathology; D048031:JNK Mitogen-Activated Protein Kinases / Q000187:drug effects / Q000378:metabolism; D019808:Losartan / Q000494:pharmacology; D051379:Mice; D010766:Phosphorylation / Q000187:drug effects; D011493:Protein Kinase C / Q000187:drug effects / Q000378:metabolism; D012333:RNA, Messenger / Q000187:drug effects / Q000378:metabolism; D044140:Receptor, Angiotensin, Type 1 / Q000235:genetics; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D053773:Transforming Growth Factor beta1 / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*
D047228:Angiotensin II Type 1 Receptor Blockers; D005353:Fibronectins; D012333:RNA, Messenger; D044140:Receptor, Angiotensin, Type 1; D053773:Transforming Growth Factor beta1; D000808:Angiotensinogen; D000804:Angiotensin II; D011493:Protein Kinase C; D048031:JNK Mitogen-Activated Protein Kinases; D005947:Glucose; D019808:Losartan