Proceedings of The Physiological Society

Physiology 2016 (Dublin, Ireland) (2016) Proc Physiol Soc 37, PCA324

Poster Communications

Metabolic programming of human foetal umbilical artery smooth muscle cells from gestational diabetic pregnancies

L. Li1, G. Jenkins2, R. C. Siow1, G. E. Mann1

1. Faculty of Life Sciences & Medicine, Cardiovascular Division, King's College London, London, United Kingdom. 2. Life Science, Unilever R&D Colworth, Sharnbrook, Bedford, United Kingdom.

Gestational diabetes mellitus (GDM) is defined as glucose intolerance with first recognition during pregnancy (Lappas et al., 2011). Offspring from GDM pregnancies have a higher risk of cardiovascular diseases in later life, most likely as a consequence of foetal programming (Lappas et al., 2011, Barker et al., 2002) . Previously we have reported that Nrf2 regulated redox signaling in foetal umbilical vein endothelial cells is impaired as a result of increased oxidative stress in GDM (Cheng et al., 2013). In the present study, redox phenotype and gene expression were characterised using human umbilical artery smooth muscle cells (HUASMC) isolated from normal (n=63) and GDM (n=32) pregnancies. Proliferation of GDM HUASMC was slower than normal HUASMC (n=5 normal and 4 GDM donors), while the cellular redox status, as determined by mitochondrial superoxide generation, intracellular glutathione (GSH) and basal protein carbonylation, were similar in normal and GDM cells (n= 5-11 normal and 5-11 GDM donors). A microarray analysis of gene expression from normal (n=9) and GDM (n=7) HUASMC cultures identified 176 differentially expressed genes, associated with in utero embryonic development, lipid metabolism, proliferation, cellular responses to stresses, proteolysis, chromatin organisation, RNA processing, transcription, and other intracellular signalling pathways. Notably, as validated by qPCR, the expression of an imprinted gene cyclin-dependent kinase inhibitor 1C (CDKN1C), an inhibitor of cell proliferation and with important function in foetal growth, was increased by 3-fold in GDM HUASMC (P<0.005, Mann-Whitney U test). In addition, validation of microarray findings by qPCR identified a 1.5-fold upregulation (P<0.05) of glutathione-S-transferase A4 (GSTA4), the key enzyme responsible for the detoxification of 4-hydroxynonenal (HNE), a lipid peroxidation product increased in GDM. Moreover, accumulation of HNE protein adducts after HNE treatment (20μM, 4h) was significantly elevated in GDM HUASMC (221 ± 74 μg/mg protein, n=5) compared to normal HUASMC (125 ± 37 μg/mg protein, n=5, mean ± S.E.M., P<0.01, two-way ANOVA), while induction of the antioxidant stress protein heme-oxygenase 1 by HNE (20 μM, 4h-8h) was lower in GDM HUASMC (P<0.05). Furthermore, a pathological concentration of HNE (100 μM, 24h) caused apoptosis in normal HUASMC (13 ± 3 %, n=6), which was significantly enhanced in GDM HUASMC (32 ± 9 %, n=6, P<0.05). The present study provides the first evidence that GDM alters gene expression and the phenotype of foetal vascular smooth muscle cells, providing valuable insights for the developmental origin of health and diseases in offspring from pregnancies associated with oxidative stress.

Where applicable, experiments conform with Society ethical requirements