Attenuation of hyperglycemia-induced apoptotic signaling and anti-angiogenic milieu in cultured cytotrophoblast cells

ABSTRACT

Objective: Preeclampsia (preE) is a hypertensive disorder that occurs 20% in diabetic pregnancy. We have shown that hyperglycemia impairs cytotrophoblast cell (CTB) function. In this study, we assess apoptotic and anti-angiogenic signaling in excess glucose-induced CTBs. Study Design: Human extravillous CTBs (Sw. 71) were treated with 100, 150, 200, 300, or 400 mg/dL glucose for 48 h. Some cells were pretreated with a p38 inhibitor (SB203580) or a peroxisome proliferator-activated receptor gamma (PPARγ) ligand (rosiglitazone) or with D-mannitol. Cell lysates were utilized to measure p38 MAPK phosphorylation, PPARγ, Bcl-2-associated-X protein (Bax), anti-apoptotic Bcl-2, caspase-9, and cyclooxygenase-2 (Cox-2) expression by western blot. Levels of the vascular endothelial growth factor (VEGF), placental growth factor (PlGF), soluble fms-like tyrosine kinase-1 (sFlt-1), soluble endoglin (sEng), and interleukin 6 (IL-6) were measured in culture media using ELISA kits. Statistical comparisons were performed using analysis of variance with Duncan’s post hoc test. Results: p38 phosphorylation and PPARγ were upregulated (p < 0.05) in CTBs treated with ≥150 mg/dL glucose compared to basal (100 mg/dL). Expressions of Bax/Bcl-2, Cox-2, and caspase-9 were upregulated (p < 0.05) in CTBs treated with ≥150 mg/dL glucose. Secretion of sFlt-1, sEng, and IL-6 was increased while VEGF and PIGF were decreased in CTB-treated ≥150 mg/dl of glucose (*p < 0.01 for each). SB203580 or rosiglitazone pretreatment significantly attenuated hyperglycemia-induced apoptotic and anti-angiogenic signaling. D-Mannitol had no effect. Conclusion: Hyperglycemia induced apoptotic and anti-angiogenic signaling in CTBs. The observed diminution of hyperglycemia-induced signaling by SB203580 or rosiglitazone pretreatment suggests the involvement of apoptotic and anti-angiogenic signaling in CTB dysfunction.

KEYWORDS:

• Anti-angiogenic
• apoptotic
• cytotrophoblast cells
• diabetes
• preeclampsia
• pregnancy

Acknowledgments

The CTB cell line Sw-71 was kindly provided by Dr. Gil G. Mor at Yale University School of Medicine, New Haven, CT, USA. The authors thank Glen Cryer for assistance with manuscript preparation.

Declaration of interest

The authors report no conflicts of interest.

Funding

Funding for this work was provided by Scott, Sherwood and Brindley Foundation and Department of Obstetrics and Gynecology (MNU) and the Noble 205 Centennial Endowment for Research in Obstetrics and Gynecology (TJK), Scott & White Healthcare, Temple, Texas.

Additional information

Funding

Funding for this work was provided by Scott, Sherwood and Brindley Foundation and Department of Obstetrics and Gynecology (MNU) and the Noble 205 Centennial Endowment for Research in Obstetrics and Gynecology (TJK), Scott & White Healthcare, Temple, Texas.