Vascular and metabolic profiles in offspring born to pregnant mice with metabolic syndrome treated with inositols.

BACKGROUND: Inositols (INOs) supplementation during pregnancy, specifically the combination of myo-inositol (MI) and D-chiro-inositol (DCI), has been reported to improve vascular parameters in women with gestational diabetes mellitus. We demonstrated previously that offspring born to pregnant mice lacking the endothelial nitric oxide synthase (eNOS+/-) gene have hypertension (HTN) as adults and, when fed a high-fat diet (HFD), develop a metabolic syndrome (MS) phenotype. OBJECTIVE: Our aim was to evaluate whether INOs treatment in pregnancy complicated by MS improves the vascular and metabolic profile in mice offspring programmed in utero to develop HTN and MS. MATERIALS AND METHODS: Heterozygous eNOS+/- mice fed an HFD manifest a MS phenotype. Female eNOS+/- mice with MS were bred with a wild-type (WT) male. On gestational day 1, pregnant females were randomly allocated to receive either a mixture of INOs (MI/DCI: 7.2/0.18 mg/mL) or water as placebo until delivery. The female offspring obtained were genotyped and categorized as: WT (genetically normal, with eNOS gene) and eNOS+/- offspring (genetically modified, heterozygous for eNOS gene). Both offspring developed in an abnormal uterine environment due to maternal MS. At 9-10 weeks of age, the offspring underwent a glucose tolerance test (GTT) and systolic blood pressure (SBP) measurement. The mice were then sacrificed, and the carotid arteries were isolated for evaluation of vascular responses. Responses to phenylephrine (PE), in the presence and absence of a nonspecific nitric oxide inhibitor (N-nitro-L-arginine methyl ester [L-NAME]), the vasodilator acetylcholine (ACh), and sodium nitroprusside (SNP) were assessed. RESULTS: The GTT showed lower glucose levels in both eNOS+/-INOs (P = .03) and WT-INOs (P = .05) offspring born to MS dams on INOs supplementation compared to offspring born to untreated dams. SBP was higher in eNOS+/- offspring compared to WT (169 ± 7 vs 142 ± 9 mm Hg, respectively, P = .04) and INOs treatment decreased SBP in WT-INOs (110 ± 10 mm Hg, P = .01) but not in eNOS+/-INOs offspring. Maximal (%Max) contractile response to PE was higher in eNOS+/- offspring born to MS dams and was decreased in those born to MS dams treated with INOs (%Max, eNOS+/-, 123 ± 7 vs eNOS+/-INOs, 82 ± 11 mm Hg, P = .007). No differences were seen in PE contractile responses in WT offspring born to MS dams treated or not treated with INOs (WT, 92 ± 4 vs WT-INOs, 75 ± 7). The L-NAME response was decreased in eNOS+/-INOs and WT-INOs offspring compared to untreated ones. The ACh vasorelaxation was impaired in eNOS+/- and WT offspring born to MS dams, and maternal INOs treatment improved offspring vascular relaxation in both offspring (P = .01 and P = .03, respectively). No differences were seen in response to SNP. CONCLUSION: Inositols supplementation improved glucose tolerance, SBP, and vascular responses in adult eNOS+/- and WT offspring born to dams with MS. Interestingly, WT born to MS dams show an altered vascular profile similar to eNOS+/- offspring and exhibit an improved response to INOs treatment. Our findings suggest that the benefits of INOs treatment are more pronounced in offspring exposed to environmental factors in utero, and less likely in those due to genetic factors.

Sildenafil treatment in a nonsevere hypertensive murine model lowers blood pressure without reducing fetal growth.

BACKGROUND: Treatment of nonsevere hypertension during pregnancy is controversial. Sildenafil is a phosphodiesterase inhibitor that potentiates nitric oxide by promoting vasodilation. Nitric oxide plays a vital role in mediating the vascular adaptations during pregnancy. OBJECTIVE: The objective of the study was to determine whether treatment with sildenafil during pregnancy would lower maternal systolic blood pressure without adversely affecting fetal growth. STUDY DESIGN: Females with nonsevere hypertension (endothelial nitric oxide synthase(+/-)) were cross-bred with normotensive wild-type males. At gestational day 1, pregnant dams were randomized to either sildenafil (0.4 mg/mL per day, comparable dose used in human pregnancy) or water for 3 weeks. Four groups were then generated: wild type (n = 7), wild type-sildenafil (n = 11), endothelial nitric oxide synthase(+/-) (n = 8), and endothelial nitric oxide synthase(+/-)sildenafil (n = 7). On gestational day 18, systolic blood pressure was measured. Dams were killed, fetal and placental weights were obtained, and carotid arteries were dissected to measure in vitro vascular reactivity with a wire-myography system. Responses to phenylephrine, L-NG-nitroarginine methyl ester, acetylcholine, and sodium nitroprusside were studied. RESULTS: Mean systolic blood pressure was elevated in the endothelial nitric oxide synthase(+/-) dams compared with wild-type controls (P = .03). Treatment with sildenafil decreased systolic blood pressure in the endothelial nitric oxide synthase(+/-)-treated dams compared with nontreated endothelial nitric oxide synthase(+/-) dams (P = .03). No differences were seen in the wild-type dams with or without sildenafil (P = .47). Fetuses from endothelial nitric oxide synthase(+/-) dams were smaller compared with wild-type controls (P < .001); however, when these endothelial nitric oxide synthase(+/-) dams were treated with sildenafil, fetal weight increased compared with the nontreated endothelial nitric oxide synthase(+/-) group (P < .001). No difference were seen in wild-type groups treated or not treated with sildenafil (P = .41). Placental weights were not significantly different among groups (endothelial nitric oxide synthase(+/-)sildenafil vs endothelial nitric oxide synthase(+/-) [P = .48]; wild-type-sildenafil vs wild type [P = .52]). Maximal vascular contraction induced by phenylephrine was blunted in endothelial nitric oxide synthase(+/-) dams treated with sildenafil compared with nontreated endothelial nitric oxide synthase(+/-) dams (P < .01). No change in contractile response was seen in wild-type groups treated or not treated (P = .53). When vessels were preincubated with L-NG-nitroarginine methyl ester, the contractile responses were similar among all groups (P = .54). In addition, maximal vascular relaxation induced by acetylcholine was improved in the endothelial nitric oxide synthase(+/-) dams treated with sildenafil compared with endothelial nitric oxide synthase(+/-) nontreated dams (P < .01). No change in relaxation response was seen in wild-type groups treated or not treated (P = .62). Sodium nitroprusside did not change the contractile response in any of the groups (P = .31). CONCLUSION: Pregnant dams deficient in endothelial nitric oxide synthase, a nonsevere hypertensive murine model, treated with sildenafil had lower maternal systolic blood pressure, increased fetal growth, and improvement in vascular reactivity. Treatment with sildenafil may be beneficial in pregnancies complicated by nonsevere hypertension.

Endothelial growth factor therapy improves preeclampsia-like manifestations in a murine model induced by overexpression of sVEGFR-1.

This study examines the effects of VEGF-121 therapy in an animal model of preeclampsia induced by overexpression of soluble VEGF receptor 1 (sVEGFR-1). At day 8 of gestation, CD-1 mice were implanted with subcutaneous osmotic pumps containing either VEGF-121 or vehicle and fitted with telemetric blood pressure (BP) catheters for continuous BP monitoring (days 8-18 of gestation). On day 9, the animals in the VEGF-121 group were randomly allocated for injection with adenovirus carrying sVEGFR-1 or the murine immunoglobulin G2α Fc fragment (mFc) as virus control (Adv-sVEGFR-1; Adv-mFc). Animals in the vehicle group were injected with Adv-sVEGFR-1. On day 18, mice were euthanized, placentas and pups weighted, carotid arteries isolated, and their responses studied in vitro using a wire myograph for isometric tension recording. In mice overexpressing sVEGFR-1, treatment with VEGF-121 significantly reduced BP from days 10 to 18 of gestation compared with that of vehicle. VEGF-sVEGFR-1 animals had significantly higher vasorelaxant response to sodium nitroprusside and significantly lower contractile response to the thromboxane agonist (U-46619) compared with that of the vehicle-sVEGFR-1 mice. Phenylephrine and acetylcholine responses did not significantly vary between the VEGF-sVEGFR-1 and the vehicle-sVEGFR-1 mice. Average pup weight was significantly lower in the vehicle-sVEGFR-1 group compared with the VEGF-sVEGFR-1 and VEGF-mFc groups. In conclusion, VEGF-121 therapy attenuates vascular dysfunction and diminishes intrauterine growth abnormality in an animal model of preeclampsia induced by overexpression of sVEGFR-1. Modulation of VEGF pathway turns into a promising therapeutic approach of preeclampsia.

Long-term maternal cardiovascular function in a mouse model of sFlt-1-induced preeclampsia.

Our aim was to evaluate the long-term effects of preeclampsia on vascular function in a mouse model induced by sFlt-1 overexpression. CD-1 mice at day 8 of gestation were injected via the tail vein with adenovirus carrying sFlt1 (AdsFlt1), adenovirus carrying the murine IgG2alpha Fc fragment as the adenovirus control (AdmFc), or saline. Vascular function in the mothers was investigated 6-8 mo after delivery by recording blood pressure (BP) by telemetry (AdsFlt1 n = 8, AdmFc n = 6, saline n = 4) and exploring carotid artery reactivity in a wire myograph (AdsFlt1 n = 6, AdmFc n = 8, saline n = 4). sFlt-1 blood levels at 6-8 mo postpartum had returned to low levels and were comparable between the three groups (P = 0.808). There was no statistically significant difference in BP (P = 0.067) or vascular reactivity between the three groups of postpartum mice (phenylephrine P = 0.079, thromboxane P = 0.979, serotonin P = 0.659, acetylcholine P = 0.795, sodium nitroprusside P = 0.728, isoproterenol P = 0.370). Our results indicate that in a mouse model overexpression of sFlt-1 does not lead to increased in BP and altered vascular function in the absence of the pregnancy and has no long-term effect on BP and vascular function in the postpartum mothers. Our findings favor the hypothesis that increased cardiovascular diseases in women with history of preeclampsia are likely the result of preexisting risk factors common to preeclampsia and cardiovascular diseases.

Maternal hypercholesterolemia leads to activation of endogenous cholesterol synthesis in the offspring.

OBJECTIVE: The purpose of this study was to determine the effect of maternal hypercholesterolemia on hepatic cholesterol metabolism in the offspring in a mouse model. STUDY DESIGN: Male and female wild type and apoE(-/-KO) (knockout for the apoprotein E [apoE]) gene) mice were crossbred to obtain all 4 possible genetic offspring types. The litters were maintained on regular chow and sacrificed at 8 months of age. Liver samples were collected and the mRNA expression levels for SCAP, SREBP-1a, SREBP-2, HMGCR, and LDLR determined using real-time RT-PCR. RESULTS: We found a significant activation of the transcriptional activity of genes involved in endogenous cholesterol synthesis, as well as LDLR, in the liver of adult mice born to hypercholesterolemic dams. CONCLUSION: Reprogramming of hepatic cholesterol homeostasis may be the basis for an increased predisposition to hypercholesterolemia and atherosclerosis found in offspring of mice exposed to a high cholesterol environment during early life.

Characterization of a murine model of fetal programming of atherosclerosis.

OBJECTIVE: The objective of the study was to investigate the effect of fetal programming on the development of atherosclerosis in the offspring in a mouse model. STUDY DESIGN: Male and female mice of the wild type and the knockout for the apoprotein E (apoE) gene were cross-bred to obtain all 4 possible genetic offspring types. The offspring were kept on regular chow and killed at 8 months of age. Levels of total cholesterol and triglycerides were determined. The aortic arch was examined for the presence and severity of atherosclerosis. Kidney and liver sections were analyzed for pathologic changes. RESULTS: We found increased total cholesterol levels and incidence of atherosclerosis in offspring born to hypercholesterolemic mothers as compared with genomically similar animals born to wild-type mothers. These animals also showed kidney and liver lesions consistent with chronic hypercholesterolemia. CONCLUSIONS: There is a strong effect of fetal programming on the development of atherosclerosis in the apoE mouse model.