The effect of tempol administration on the aortic contractile responses in rat preeclampsia model

Mito-targeted antioxidant prevents cardiovascular remodelling in spontaneously hypertensive rat by modulation of energy metabolism

Hypertension induced left ventricular hypertrophy (LVH) augments the risk of cardiovascular anomalies. Mitochondrial alterations result in oxidative stress, accompanied by decrease in fatty acid oxidation, leading to the activation of the hypertrophic program. Targeted antioxidants are expected to reduce mitochondrial reactive oxygen species more effectively than general antioxidants. This study was designed to assess whether the mito-targeted antioxidant, Mito-Tempol (Mito-TEMP) is more effective than the general oxidant, Tempol (TEMP) in reduction of hypertension and hypertrophy and prevention of shift in cardiac energy metabolism. Spontaneously hypertensive rats were administered either TEMP (20 mg/kg/day) or Mito-TEMP (2 mg/kg/day) intraperitoneally for 30 days. Post treatment, animals were subjected to 2D-echocardiography. Myocardial lysates were subjected to RPLC - LTQ-Orbitrap-MS analysis. Mid-ventricular sections were probed for markers of energy metabolism and fibrosis. The beneficial effect on cardiovascular structure and function was significantly higher for Mito-TEMP. Increase in mitochondrial antioxidants and stimulation of fatty acid metabolism; with significant improvement in cardiovascular function was apparent in spontaneously hypertensive rats (SHR) treated with Mito-TEMP. The study indicates that Mito-TEMP is superior to its non- targeted isoform in preventing hypertension induced LVH, and the beneficial effects on heart are possibly mediated by reversal of metabolic remodelling.

Comparison of steroid hormones in three different preeclamptic models

Preeclampsia (PE) is a complication of pregnancy and is characterized by hypertension and proteinuria, threatening both the mother and the fetus. However, the etiology of PE has not yet been fully understood. Since the imbalance of steroid hormones is associated with the pathogenesis of PE, investigating steroidogenic mechanisms under various PE conditions is essential to understand the entire spectrum of pregnancy disorders. Therefore, the current study established three PE in vitro and in vivo models, and compared the levels of steroid hormones and steroidogenic enzymes within them. In cellular PE models induced by hypoxia, N‑nitro‑L‑arginine methyl ester hydrocholride (L‑NAME) and catechol‑o‑methyltransferase inhibitor, the levels of steroid hormones, including pregnenolone (P5), progesterone (P4), dehydroepiandrosterone (DHEA) and testosterone tended to decrease during steroidogenesis. Injection of L‑NAME in pregnant rats led to a reduction in the levels of estradiol and P4 through regulation of cholesterol side‑chain cleavage enzyme (CYP11A1) and 3β‑hydroxysteroid dehydrogenase/δ5 4‑isomerase type 1 (HSD3B1), whereas rats treated with COMT‑I exhibited elevated levels of P5 and DHEA by regulation of the CYP11A1 and aromatase cytochrome P450 (CYP19A1) in the placenta and plasma. The reduced uterine perfusion pressure operation decreased CYP11A1 and increased CYP19A1 expression in placental tissues, whereas steroid hormone levels were not altered. In conclusion, the results of the present study suggest that the induction of PE conditions dysregulates the steroid hormones via regulation of steroidogenic enzymes, depending on specific PE symptoms. These findings can contribute to the development of novel diagnostic and therapeutic modalities for PE, by monitoring and supplying appropriate levels of steroid hormones.

Açaí (Euterpe oleracea Mart) seed extract protects against maternal vascular dysfunction, hypertension, and fetal growth restriction in experimental preeclampsia

Objective: To investigate whether Euterpe oleracea Mart. (açaí) seed extract (ASE) prevents maternal cardiovascular changes and intrauterine growth restriction (IUGR) in experimental preeclampsia (PE).Methods: ASE administration (200 mg/kg/day) during mid to late pregnancy in a rat model of L-NAME-induced PE.Results: ASE impaired the maternal hypertension and microalbuminuria as well as the lower fetal and placental weight in experimental PE. ASE also prevented the maternal vascular dysfunction and lipoperoxidation in this model.Conclusion: ASE protected against maternal cardiovascular changes and IUGR in the L-NAME-induced PE. The protective effect of ASE may be partly explained by its antioxidant property.

Exploring a New Natural Treating Agent for Primary Hypertension: Recent Findings and Forthcoming Perspectives

Primary hypertension describes abnormally-high systolic/diastolic blood pressure in a resting condition caused by various genetic or environmental risk factors. Remarkably, severe complications, such as ischemic cardiovascular disease, stroke, and chronic renal disease have led to primary hypertension becoming a huge burden for almost one-third of the total population. Medication is the major regimen for treating primary hypertension; however, recent medications may have adverse effects that attenuate energy levels. Hence, the search for new hypotensive agents from folk or traditional medicine may be fruitful in the discovery and development of new drugs. This review assembles recent findings for natural antihypertensive agents, extracts, or decoctions published in PubMed, and provides insights into the search for new hypotensive compounds based on blood-pressure regulating mechanisms, including the renin-angiotensin-aldosterone system and the sympathetic/adrenergic receptor/calcium channel system.

siRNA-mediated NCAM1 gene silencing suppresses oxidative stress in pre-eclampsia by inhibiting the p38MAPK signaling pathway

Pre-eclampsia (PE), whose pathophysiology and etiology remain undefined, represents a leading consequence of fetal and maternal mortality and morbidity. Oxidative stress (OS) is recognized to involve in this disorder. In this study, we hypothesized that neural cell adhesion molecule 1 (NCAM1) gene silencing would suppress the OS in the pregnancy complicated by PE. Initially, clinical samples were collected for determination of NCAM1 expression in placental tissues and levels of OS products in blood. To assess the regulatory mechanism of NCAM1 knockdown on OS, we used small interfering RNA (siRNA) to silence NCAM1 expression in human umbilical vein endothelial cells (HUVECs). Next, cells were treated with or without hypoxia/reoxygenation to observe the level changes of OS products and p38 mitogen-activated protein kinase (p38MAPK) pathway-related genes. Finally, an evaluation of HUVEC migration and invasion abilities was conducted by wound-healing and transwell assays. Placenta of pregnancy with PE presented significantly increased NCAM1 expression in comparison to placenta of normal pregnancy. Meanwhile, enhanced OS in blood of pregnant women with PE was observed relative to women with normal pregnancy. siRNA-mediated knockdown of NCAM1 gene could inhibit the p38MAPK signaling pathway, repress OS, and promote cell migration and invasion in HUVECs, indicating that NCAM1 inhibition could reduce the influence of PE. Importantly, blocking the p38MAPK signaling pathway reversed the inhibitory role of NCAM1 gene silencing on PE. Collectively, this study defines potential role of NCAM1 gene silencing as a therapeutic target in PE through inhibiting OS and enhancing HUVEC migration and invasion by disrupting the p38MAPK signaling pathway.

A potential role of Baicalin to inhibit apoptosis and protect against acute liver and kidney injury in rat preeclampsia model

The incidence of acute liver and kidney injury in pregnancy is companied by Preeclampsia (PE), which has remained a major cause of maternal and fetal morbidity, and mortality. Therefore, a significant treatment to protect against liver and kidney injury of PE requires new drugs to develop potential therapeutic benefits to the clinic. Baicalin played protection role on inhibition of cell apoptosis which is a potential drug for keep liver and kidney from acute injury on PE patients. In this study, we made PE rat disease model with liver and kidney acute injury, and then used low-, medium-, and high-dose of Baicalin to treat PE rat, respectively. We found that Baicalin attenuated acute injury symptoms and inhibited apoptosis of rat liver and kidney tissues. The intervention of Baicalin increased the expression of anti-apoptotic protein XIAP and Bcl-2, reduced the expression of apoptotic protein Caspase-9 in rat liver; and similarly, Baicalin increased the expression of Bcl-2, while inhibited Caspase-9 and AT1 in rat kidney. Interestingly, Baicalin intervention with medium dose showed a better function for inhibiting apoptosis. Our data suggests that Baicalin is a potentially therapeutic candidate for preventing liver and kidney damage, which shed a light on therapeutic benefit for PE rat models.

Differential responses of mesenteric arterial bed to vasoactive substances in L-NAME-induced preeclampsia: Role of oxidative stress and endothelial dysfunction

To investigate the systemic and placental oxidant status as well as vascular function in experimental preeclampsia (PE) induced by nitro-L-arginine methyl ester (L-NAME). Fetal parameters and maternal blood pressure, proteinuria, mesenteric arterial bed (MAB) reactivity, and systemic and placental oxidative stress were compared between four groups: pregnant rats receiving L-NAME (60 mg/kg/day, orally) (P + L-NAME) or vehicle (P) from days 13 to 20 of pregnancy and nonpregnant rats receiving L-NAME (NP + L-NAME) or vehicle (NP) during 7 days. L-NAME administration during pregnancy induced some hallmarks of PE, such as hypertension and proteinuria. The P + L-NAME group presented lower weight gain and placental mass as well as reduced number and weight of live fetuses than P group. The vasodilator effect induced by acetylcholine (ACh) and angiotensin II (Ang II) was lower in the perfused MAB from NP + L-NAME and P + L-NAME than in control groups. Otherwise, the nitroglycerine-induced vasodilation and the phenylephrine- and Ang II-induced vasoconstriction were higher in MAB from NP + L-NAME and P + L-NAME groups than in the respective controls. Systemic and placental oxidative damage, assessed by malondialdehyde and carbonyl levels, was increased and activities of the antioxidant enzymes superoxide dismutase and glutathione peroxidase were reduced in P + L-NAME and NP + L-NAME groups compared to controls. The present data suggest that the oxidative stress and reduced bioavailability of nitric oxide may contribute to attenuation of vasodilator responses to ACh and Ang II, and hyperreactivity to Ang II in the mesentery of preeclamptic rat, which may contribute to the increased peripheral vascular resistance and BP, as well as intrauterine growth restriction in L-NAME-induced PE.

Simvastatin Alleviates Pathology in a Rat Model of Preeclampsia Involving ERK/MAPK Pathway

Preeclampsia (PE) is a pregnancy-specific condition characterized by new-onset hypertension. There is evidence suggesting that imbalances of angiogenic factors, oxidative stress, and inflammation may be central to the pathogenesis of PE. We sought to investigate whether simvastatin would reduce mean arterial pressure, restore the angiogenic balance, and ameliorate inflammation and oxidative stress in a nitric oxide synthase inhibitor NG-nitro-l-arginine methyl ester (l-NAME)-induced rat model of PE. We found that blood pressure was significantly increased in the l-NAME group compared to normal pregnant dams ( P < .01), and simvastatin reduced this difference. In addition, dams from the l-NAME group showed lower vascular endothelial growth factor (VEGF) and interleukin (IL) 10 levels and higher plasma-soluble FMS-like tyrosine kinase 1 (sFlt-1), tumor necrosis factor α (TNF-α), and oxidative stress marker malondialdehyde (MDA) levels as compared to control dams ( P < .01, for all). Interestingly, simvastatin treatment significantly increased VEGF and IL-10 levels while decreased sFlt-1, TNF-α, and MDA levels compared to the untreated l-NAME group. Moreover, simvastatin treatment significantly upregulated protein expression of placental p-extracellular signal-regulated kinase (ERK1), p-p38 mitogen-activated protein kinase (MAPK), p-c-Jun N-terminal kinase, and p-protein kinase B compared to untreated l-NAME control. These results suggest that simvastatin treatment restores angiogenic balance and ameliorates inflammation and oxidative stress in a rat model of PE involving ERK/MAPK pathway.

Decitabine Improves the Clinical Manifestations of Rats With l-NAME-Induced Pre-eclampsia: A Potential Approach to Studying Pre-eclampsia

OBJECTIVE

Pre-eclampsia is a major cause of maternal mortality and morbidity. Conditions with low oxygen tension are regarded as a key factor. Decitabine can partly attenuate the effects of hypoxia. This research was designed to investigate the effects of decitabine in rats with NG-Nitro-L-arginine Methyl Eater (L-NAME) induced pre-eclampsia and to explore the molecular mechanisms.

METHODS

A Wistar rat model of pre-eclampsia was established by intraperitoneal injection of L-NAME, and the intervention reagent was decitabine. Blood pressure (BP) and 24-h urinary protein were monitored. The expression of Mammary Serine Protease Inhibitor (SERPINB5, maspin) in the placenta was detected by reverse transcriptase-polymerase chain reaction (RT-PCR) and western blotting.

RESULTS

Systolic BP in the tail artery of pregnant rats was increased by more than 30 mm Hg, and 24-h urinary protein was significantly increased after L-NAME was added. After decitabine treatment, blood pressure and 24-h urinary protein were significantly decreased. The expression of SERPINB5 in the placenta significantly increased after L-NAME was added. Decitabine significantly elevated the expression of SERPINB5 in the placenta of rats with L-NAME-induced preeclampsia.

CONCLUSION

Decitabine reduced 24-h urinary protein and partly decreased blood pressure of pre-eclampsia in late pregnancy in rats with L-NAME-induced pre-eclampsia and increased the expression of SERPINB5, but the molecular mechanism of decitabine's effect remains unknown. This research provided a potential approach to studying the pathogenesis, treatment and prevention of pre-eclampsia.

Acute reactive oxygen species (ROS)-dependent effects of IL-1β, TNF-α, and IL-6 on the glomerular filtration barrier (GFB) in vivo

This study was performed to investigate the immediate actions of the proinflammatory cytokines IL-1β, TNF-α, and IL-6 on the permeability of the glomerular filtration barrier (GFB) in rats and to test whether these actions are dependent upon the release of reactive oxygen species (ROS). In anesthetized rats, blood access was achieved and the left ureter was cannulated for urine collection. Rats were continuously infused intravenously with either IL-1β (0.4 and 2 μg·kg(-1)·h(-1)), TNF-α (0.4 and 2 μg·kg(-1)·h(-1)), or IL-6 (4 and 8 μg·kg(-1)·h(-1)), together with polydisperse FITC-Ficoll-70/400 and inulin for 1 h. Plasma and urine samples were analyzed by high performance size exclusion chromatography (HPSEC) for determination of glomerular sieving coefficients (θ). The glomerular filtration rate (GFR) was also assessed (51Cr-EDTA). In separate experiments, the superoxide scavenger tempol (30 mg·kg(-1)·h(-1)) was given before and during cytokine infusions. IL-1β and TNF-α caused rapid, partly reversible increases in glomerular permeability to large molecules (Ficoll50-80Å), peaking at 5-30 min, while IL-6 caused a more gradual increase in permeability, leveling off at 60 min. Tempol almost completely abrogated the glomerular permeability effects of the cytokines infused. In conclusion IL-1β, TNF-α, and IL-6, when infused systemically, caused immediate and partly reversible increases in glomerular permeability, which could be inhibited by the superoxide scavenger tempol, suggesting an important role of ROS in acute cytokine-induced permeability changes in the GFB.

Assessment of therapeutic efficacy of miR-126 with contrast-enhanced ultrasound in preeclampsia rats

Preeclampsia is a pregnancy-specific syndrome characterized by high blood pressure and proteinuria, which has a pathophysiology of insufficient placental blood perfusion. MicroRNA-126 (miR-126), an angiogenesis-related miRNA, has been proved to play a significant role in endothelial cells response to ischemia in vitro and in vivo. However, whether miR-126 has therapeutic potential in vasculogenesis of preeclampsia placenta remains uncertain. In this study, we focused our attention on this unsolved problem. First, we established the preeclampsia animal model and over-expressed miR-126 in vivo using a specific agomir. Then we described the effects of miR-126 on placental vasculogenesis in preeclampsia rats, including the evaluation of placental blood perfusion using microbubbles-assisted contrast-enhanced ultrasonography (CEUS), placental histology, immunohistochemistry and pregnancy outcome. Finally, we investigated the possible target gene and pathway that miR-126 modulates. Together, our results showed that preeclampsia animal with over-expressed miR-126 had higher pup weight, placenta weight and proportion of live pups. Quantification of uteroplacental perfusion by CEUS and CD34 staining of placental tissue revealed that blood volume and microvessel density increased in miR-126 treated group. MiR-126 was related to PIK3R2 down-regulation and Akt activation within placenta, which had impacts on vascularization of placenta. Therefore, miR-126 may be an efficient gene therapy to promote angiogenesis and blood perfusion in preeclampsia placenta.

The synthetic triterpenoid RTA dh404 (CDDO-dhTFEA) restores endothelial function impaired by reduced Nrf2 activity in chronic kidney disease

Chronic kidney disease (CKD) is associated with endothelial dysfunction and accelerated cardiovascular disease, which are largely driven by systemic oxidative stress and inflammation. Oxidative stress and inflammation in CKD are associated with and, in part, due to impaired activity of the cytoprotective transcription factor Nrf2. RTA dh404 is a synthetic oleanane triterpenoid compound which potently activates Nrf2 and inhibits the pro-inflammatory transcription factor NF-κB. This study was designed to test the effects of RTA dh404 on endothelial function, inflammation, and the Nrf2-mediated antioxidative system in the aorta of rats with CKD induced by 5/6 nephrectomy. Sham-operated rats served as controls. Subgroups of CKD rats were treated orally with RTA dh404 (2 mg/kg/day) or vehicle for 12 weeks. The aortic rings from untreated CKD rats exhibited a significant reduction in the acetylcholine-induced relaxation response which was restored by RTA dh404 administration. Impaired endothelial function in the untreated CKD rats was accompanied by significant reduction of Nrf2 activity (nuclear translocation) and expression of its cytoprotective target genes, as well as accumulation of nitrotyrosine and upregulation of NAD(P)H oxidases, 12-lipoxygenase, MCP-1, and angiotensin II receptors in the aorta. These abnormalities were ameliorated by RTA dh404 administration, as demonstrated by the full or partial restoration of the expression of all the above analytes to sham control levels. Collectively, the data demonstrate that endothelial dysfunction in rats with CKD induced by 5/6 nephrectomy is associated with impaired Nrf2 activity in arterial tissue, which can be reversed with long term administration of RTA dh404.

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Endothelial dysfunction in rats with chronic kidney disease is associated with impaired aortic Nrf2 activity.

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Long-term administration of the Nrf2 activator RTA dh404 ameliorated downregulation of Nrf2 and vascular dysfunction induced by chronic kidney disease.

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Long-term administration of the Nrf2 activator RTA dh404 ameliorated chronic kidney disease-induced accumulation of nitrotyrosine and upregulation of NF-κB target genes.