To address the role of PKC isoforms in hyperglycemia-induced apoptosis and malformations in the embryos of diabetic pregnancies, expression of PKCα, β1, β 2, γ, δ, ε, and ζ was examined in the neural tube of rat embryos and showed to overlap with the regions of increased apoptosis. Levels of activated (phosphorylated) PKCα , β2, and δ were increased in the embryos of diabetic dams whereas those of PKCε and ζ were decreased when compared with those in control groups. Cytosolic phospholipase A2 (cPLA2) was also activated. Blocking the activity of PKCα , β2, and δ using isoform-specific inhibitors in embryos cultured in hyperglycemia (40 mM) reduced malformation rates when compared with those in untreated hyperglycemic and euglycemic (8.3 mM) groups. These observations demonstrate that PKCα, β2, and δ play an essential role in diabetic embryopathy. Activation of cPLA2 was also decreased, suggesting that PKCs mediate the hyperglycemic effects through the cPLA2-phospholipid peroxidation pathway.
Mills JLMalformations in infants of diabetic mothers. Teratology. 1982;25:385-394.
2.
Zhao Z., Reece EAExperimental mechanisms of diabetic embryopathy and strategies for developing therapeutic interventions. J Soc Gynecol Investig. 2005;12:549-557.
3.
Loeken MRCurrent perspectives on the causes of neural tube defects resulting from diabetic pregnancy. Am J Med Genet C Semin Med Genet. 2005;135:77-87.
4.
Reece EA, Eriksson UJThe pathogenesis of diabetes-associated congenital malformations. Obstet Gynecol Clin North Am. 1996;23:29-45.
5.
Colas JF, Schoenwolf GCTowards a cellular and molecular understanding of neurulation. Dev Dyn. 2001;221:117-145.
6.
Fine EL, Horal M., Chang TI, Fortin G., Loeken MREvidence that elevated glucose causes altered gene expression, apoptosis, and neural tube defects in a mouse model of diabetic pregnancy. Diabetes. 1999;48:2454-2462.
7.
Forsberg H., Eriksson UJ, Welsh N.Apoptosis in embryos of diabetic rats. Pharmacol Toxicol. 1998;83:104-111.
8.
Reece EA, Homko CJ, Wu YK, Wiznitzer A.The role of free radicals and membrane lipids in diabetes-induced congenital malformations. J Soc Gynecol Investig. 1998 ;5:178-187.
9.
Sakamaki H., Akazawa S., Ishibashi M., et al. Significance of glutathione-dependent antioxidant system in diabetes-induced embryonic malformations. Diabetes. 1999;48:1138-1144.
10.
Wiznitzer A. , Furman B., Mazor M., Reece EAThe role of prostanoids in the development of diabetic embryopathy. Semin Reprod Endocrinol. 1999;17:175-181.
11.
Cederberg J. , Basu S., Eriksson UJIncreased rate of lipid peroxidation and protein carbonylation in experimental diabetic pregnancy. Diabetologia . 2001;44:766-774.
12.
Wentzel P., Welsh N., Eriksson UJDevelopmental damage, increased lipid peroxidation, diminished cyclooxygenase-2 gene expression, and lowered prostaglandin E2 levels in rat embryos exposed to a diabetic environment. Diabetes. 1999;48:813-820.
13.
Morrow JD, Hill KE, Burk RF, Nammour TM, Badr KF, Roberts LJA series of prostaglandin F2-like compounds are produced in vivo in humans by a non-cyclooxygenase, free radical-catalyzed mechanism. Proc Nat Acad Sci U S A. 1990; 87:9383-9387.
14.
Morrow JDThe isoprostanes: their quantification as an index of oxidant stress status in vivo. Drug Metab Rev. 2000; 32:377-385.
15.
Kudo I., Murakami M.Regulatory functions of prostaglandin E2 synthases. Adv Exp Med Biol. 2003;525:103-106.
16.
Wentzel P., Eriksson UJAntioxidants diminish developmental damage induced by high glucose and cyclooxygenase inhibitors in rat embryos in vitro. Diabetes. 1998;47:677-684.
17.
Piddington R. , Joyce J., Dhanasekaran P., Baker L.Diabetes mellitus affects prostaglandin E2 levels in mouse embryos during neurulation. Diabetologia. 1996;39:915-920.
18.
Clark JD, Schievella AR, Nalefski EA, Lin LLCytosolic phospholipase A2. J Lipid Mediat Cell Signal. 1995;12:83-117.
19.
Lin WW, Chen BCDistinct PKC isoforms mediate the activation of cPLA2 and adenylyl cyclase by phorbol ester in RAW264.7 macrophages. Br J Pharmacol . 1998;125:1601-1609.
20.
Dempsey EC, Newton AC, Mochly-Rosen D., et al. Protein kinase C isozymes and the regulation of diverse cell responses. Am J Physiol Lung Cell Mol Physiol. 2000;279:L429-L438.
21.
Shirai Y., Saito N.Activation mechanisms of protein kinase C: maturation, catalytic activation, and targeting. J Biochem. 2002;132:663-668.
22.
Sheetz MJ, King GLMolecular understanding of hyperglycemia's adverse effects for diabetic complications . JAMA. 2002;288:2579-2588.
23.
Way KJ, Katai N., King GLProtein kinase C and the development of diabetic vascular complications. Diabet Med. 2001;18:945-959.
24.
Gutterman DDVascular dysfunction in hyperglycemia: is protein kinase C the culprit? Circ Res. 2002;90:5-7.
25.
HiramatsuY,Sekiguchi N., Hayashi M., et al. Diacylglycerol production and protein kinase C activity are increased in a mouse model of diabetic embryopathy. Diabetes . 2002;51:2804-2810.
26.
Wentzel P., Wentzel CR, Gareskog MB, Eriksson UJInduction of embryonic dysmorphogenesis by high glucose concentration, disturbed inositol metabolism, and inhibited protein kinase C activity. Teratology. 2001;63:193-201.
27.
Gareskog M. , Wentzel P.Altered protein kinase C activation associated with rat embryonic dysmorphogenesis. Pediatr Res. 2004;56:849-857.
28.
Reece EA,Wu,YKZhao Z., Dhanasekaran D.Dietary vitamin and lipid therapy rescues aberrant signaling and apoptosis and prevents hyperglycemia-induced diabetic embryopathy in rats. Am J Obstet Gynecol. 2006;194:580-585.
29.
Reece EA, Ma XD, Zhao Z., Wu YK, Dhanasekaran D.Aberrant patterns of cellular communication in diabetes-induced embryopathy in rats: II, apoptotic pathways. Am J Obstet Gynecol. 2005;192:967-972.
30.
Reece EA, Wiznitzer A., Homko CJ, Hagay Z., Wu YKSynchronization of the factors critical for diabetic teratogenesis: an in vitro model. Am J Obstet Gynecol. 1996;174:1284-1288.
31.
Zhao Z., Reece EANicotine-induced embryonic malformations mediated by apoptosis from increasing intracellular calcium and oxidative stress. Birth Defects Res B Dev Reprod Toxicol. 2005;74:383-391.
32.
Reece EA, Pinter E., Leranth CZ, et al. Ultrastructural analysis of malformations of the embryonic neural axis induced by in vitro hyperglycemic conditions. Teratology . 1985;32:363-373.
33.
Zhao Z., Rivkees SAProgrammed cell death in the developing heart: regulation by BMP4 and FGF2 . Dev Dyn. 2000;217: 388-400.
34.
Gäreskog M. , Wentzel P.N-Acetylcysteine and α-cyano-4-hydroxycinnamic acid alter protein kinase C (PKC)-δ and PKC-ζ and diminish dysmorphogenesis in rat embryos cultured with high glucose in vitro. J Endocrinol . 2007;192:207-214.
35.
Eriksson UJ , Borg LA, Cederberg J., et al. Pathogenesis of diabetes-induced congenital malformations. UpsJMed Sci. 2000; 105:53-84.
