Rexhaj E, Pireva A, Paoloni-Giacobino A, Allemann Y, Cerny D, Dessen P, Sartori C, Scherrer U, Rimoldi SF. Prevention of vascular dysfunction and arterial hypertension in mice generated by assisted reproductive technologies by addition of melatonin to culture media. Am J Physiol Heart Circ Physiol 309: H1151-H1156, 2015. First published August 14, 2015; doi:10.1152/ajpheart.00621.2014.-Assisted reproductive technologies (ART) induce vascular dysfunction in humans and mice. In mice, ART-induced vascular dysfunction is related to epigenetic alteration of the endothelial nitric oxide synthase (eNOS) gene, resulting in decreased vascular eNOS expression and nitrite/nitrate synthesis. Melatonin is involved in epigenetic regulation, and its administration to sterile women improves the success rate of ART. We hypothesized that addition of melatonin to culture media may prevent ART-induced epigenetic and cardiovascular alterations in mice. We, therefore, assessed mesenteric-artery responses to acetylcholine and arterial blood pressure, together with DNA methylation of the eNOS gene promoter in vascular tissue and nitric oxide plasma concentration in 12-wk-old ART mice generated with and without addition of melatonin to culture media and in control mice. As expected, acetylcholine-induced mesenteric-artery dilation was impaired (P ϭ 0.008 vs. control) and mean arterial blood pressure increased (109.5 Ϯ 3.8 vs. 104.0 Ϯ 4.7 mmHg, P ϭ 0.002, ART vs. control) in ART compared with control mice. These alterations were associated with altered DNA methylation of the eNOS gene promoter (P Ͻ 0.001 vs. control) and decreased plasma nitric oxide concentration (10.1 Ϯ 11.1 vs. 29.5 Ϯ 8.0 M) (P Ͻ 0.001 ART vs. control). Addition of melatonin (10 Ϫ6 M) to culture media prevented eNOS dysmethylation (P ϭ 0.005, vs. ART ϩ vehicle), normalized nitric oxide plasma concentration (23.1 Ϯ 14.6 M, P ϭ 0.002 vs. ART ϩ vehicle) and mesentery-artery responsiveness to acetylcholine (P Ͻ 0.008 vs. ART ϩ vehicle), and prevented arterial hypertension (104.6 Ϯ 3.4 mmHg, P Ͻ 0.003 vs. ART ϩ vehicle). These findings provide proof of principle that modification of culture media prevents ART-induced vascular dysfunction. We speculate that this approach will also allow preventing ART-induced premature atherosclerosis in humans. STUDIES IN ANIMALS AND HUMANS demonstrate that adverse events during early life induce vascular dysfunction that may predispose to premature cardiovascular morbidity and mortality (1,2,10,19,24). Assisted reproductive technologies (ART) represent a recent important example of this problem, since ART induces vascular and cardiac dysfunction in children (26,33,34) and causes premature vascular aging and arterial hypertension that are associated with a shortened life span in mice (20). Consistent with observations in humans suggesting that decreased nitric oxide [nitrate/nitrite (NOx)] bioavailability contributes to vascular dysfunction in the offspring of ART (22), data in ART mice indicate that epigenetic alterations of the endotheli...

In humans assisted reproductive technologies (ART) induce generalized vascular dysfunction in children. In line with this observation, ART induces vascular dysfunction and arterial hypertension in mice that is related to an epigenetic mechanism, but the long term consequences are unknown. To address this problem, we compared the long term survival of ART and control mice fed a normal chow diet (NC) or challenged with a high‐fat diet (HFD).80 male FVB mice generated by ART and 80 control mice born and raised in our animal facility were observed in these studies. Three to four animals were placed in a cage in the clean conventional mouse facility. 6 ART and 7 control mice had to be sacrificed because of injuries related to fighting. 32 ART and 20 control mice were fed NC, 42 ART mice and 53 control mice were fed a HFD (49.5% fat, 31.5% protein and 0% carbohydrate). Kaplan‐Meier survival curves were constructed using known birth and death dates and the log‐rank test was used to evaluate statistical differences between groups.We found that in mice fed with NC the life span was similar in the two groups. In contrast, HFD, while not having a detectable effect on life span in control mice, reduced the survival in ART‐mice by roughly 25%(P<0.0001).ART is associated with a marked reduction of the life span in normal mice challenged with a Western style high‐fat diet.

In mice, restrictive diet pregnancy (RDP), a model mimicking preeclampsia in humans, induces vascular dysfunction in the offspring that is related to decreased vascular nitric oxide (NO) bioavailability. There is abundant evidence that NO plays an important role in the regulation of insulin sensitivity in animals and humans. We speculated that offspring of RDP mice are insulin‐resistant.We, therefore, assessed insulin sensitivity (euglycemic‐hyperinsulinemic clamp studies) in offspring of RDP and control mice fed with high‐fat diet (HFD) for 8 wks. The main new finding was that HFD induced much more severe insulin resistance in offspring of RDP than in control mice, as evidenced by a markedly smaller glucose infusion rate to maintain euglycemia (77.4±10.7 vs. 96.7±12.2, P<.001) in offspring of RDP than in control mice. Insulin resistance was not related to an intrinsic defect of skeletal muscle because muscle glucose uptake was comparable in the 2 groups. In analogy to other NO‐deficient states, this problem is probably related to vascular dysfunction resulting in impaired insulin stimulation of blood flow and substrate delivery to skeletal muscle tissue. Preeclampsia‐induced vascular dysfunction has also been found in humans. We speculate that preeclampsia represents a novel risk factor facilitating diet‐induced insulin resistance in humans.Grant support: Swiss National Science Foundation and Swiss Society of Hypertension