We have demonstrated that vascular endothelial growth factor (VEGF) is expressed in capillary pericytes of the developing corpus luteum (CL) and others have shown that basic fibroblast growth factor (FGF2) and angiopoietins (ANGPT) are present in the CL. VEGF and FGF2 target endothelial cells to initiate angiogenesis and stimulate nitric oxide (NO) production. Conversely, NO may increase VEGF expression by vascular smooth muscle cells and pericytes. To investigate the relationship between these angiogenic factors and NO in the CL, microvascular pericytes and endothelial cells were isolated from CL collected from superovulated ewes (n ≤ 5) on d 9 of the estrous cycle. Pericytes were identified by their morphology in culture and by immunofluorescent staining for smooth muscle cell actin. Pericytes were incubated with or without varying doses of the NOdonor DETA-NO for 8 h. Then, total cellular RNA was extracted from the cells and evaluated for expression of mRNA for VEGF, FGF2, ANGPT1, ANGPT2, and NO receptor, guanylate cyclase 1, soluble β3 (GUCY1B3), using real-time quantitative RT-PCR. NO caused a dosedependent increase in VEGF (p < 0.001), FGF2 (p < 0.001), ANGPT2 (p < 0.06), and GUCY1B3 (p < 0.03) mRNA expression. Expression of mRNA for ANGPT1 in luteal pericytes was not affected by the NO treatment. These data provide further evidence of the role of the luteal pericyte and NO in angiogenic factor expression, and of the potential interactions of pericytes with endothelial cells via NO production.
Bibliographical noteFunding Information:
The authors would like to acknowledge the kind assistance of Dr. Ronald R. Magness and Ms. Gladys Lopez, Perinatal Research Laboratories, University of Wisconsin– Madison, for performing the NO analysis for our preliminary studies. Thank you to Disha Pant, Dr. Justin Luther, Corrie Redmer, Kimberly Petry, Ewa Borowczyk, Dr. Jerzy J. Bilski, James Kirsch, Kim Kraft, Robert Weigl and other members of our laboratory for their technical assistance in establishing the luteal cell lines, and to Dr. Chainarong Navanukraw and Julie Berg for their assistance in preparing the manuscript. Supported, in part, by a USDA Grant 2002-35203-12246 to D.A. Redmer and L.P. Reynolds, and an NSF Science Bound Fellowship and a NASA Undergraduate Research Grant to J.D. Beckman.
- Corpus luteum
- Nitric oxide