Low Dose of IL-2 Normalizes Hypertension and Mitochondrial Function in the RUPP Rat Model of Placental Ischemia

IL-2 is a cytokine released from CD4+T cells with dual actions and can either potentiate the inflammatory response or quell a chronic inflammatory response depending on its circulating concentration. IL-2 is elevated in many chronic inflammatory conditions and is increased during preeclampsia (PE). PE is characterized by new-onset hypertension during pregnancy and organ dysfunction and increasing evidence indicates that proinflammatory cytokines cause hypertension and mitochondrial (mt) dysfunction during pregnancy. The reduced uterine perfusion pressure (RUPP) model of placental ischemia is a rat model of PE that we commonly use in our laboratory and we have previously shown that low doses of recombinant IL-2 can decrease blood pressure in RUPP rats. The objective of this study was to determine the effects of a low dose of recombinant IL-2 on multi-organ mt dysfunction in the RUPP rat model of PE. We tested our hypothesis by infusing recombinant IL-2 (0.05 ng/mL) into RUPP rats on GD14 and examined mean arterial pressure (MAP), renal, placental and endothelial cell mt function compared to control RUPP. MAP was elevated in RUPP rats (n = 6) compared to controls (n = 5) (122 ± 5 vs. 102 ± 3 mmHg, p < 0.05), but was reduced by administration of LD recombinant IL-2 (107 ± 1 vs. 122 ± 5 mmHg, n = 9, p < 0.05). Renal, placental and endothelial mt ROS were significantly increased in RUPP rats compared to RUPP+ IL-2 and controls. Placental and renal respiration rates were reduced in RUPP rats compared to control rats but were normalized with IL-2 administration to RUPPs. These data indicate that low-dose IL-2 normalized multi-organ mt function and hypertension in response to placental ischemia.

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Abstract P320: Proliferationof Endogenous T-regs Improves the Pathophysiology Associated with Placental Ischemia of Pregnancy

Hypertension ◽

10.1161/hyp.68.suppl_1.p320 ◽

2016 ◽

Vol 68 (suppl_1) ◽

Author(s):

Tarek Ibrahim ◽

Lukasz Przybyl ◽

Ashlyn C Harmon ◽

Denise C Connelius ◽

Mark W Cunningham ◽

...

Keyword(s):

Blood Pressure ◽

Inflammatory Cytokines ◽

Perfusion Pressure ◽

Treg Cells ◽

Proinflammatory Response ◽

Regulatory Interactions ◽

Uterine Perfusion ◽

Placental Ischemia ◽

Pro Inflammatory Cytokines ◽

New Onset

Preeclampsia (PE), new onset hypertension during pregnancy, is associated with pro-inflammatory cytokines and decreased regulatory immune mechanisms such as Tregs, IL-10 and IL-4. We believe this decrease in immune regulatory mechanisms leads to an uncontrolled proinflammatory response which contributes to most of the pathophysiology associated with PE. The Reduced Uterine Perfusion Pressure, RUPP, rat model of induced placental ischemia exhibits similar characteristics as women with PE including high blood pressure, elevated pro-inflammatory cytokines and cells and decreased Tregs, IL-4 and IL-10. Therefore, we hypothesized that stimulating Tregs by administration of a superagonist (SA) would increase the Treg profile in the RUPP rats which could reduce pro-inflammatory cytokines and blood pressure. The RUPP procedure was performed at gestation day 14 (GD14); SA was administered intraperitoneally at GD15, GD18 carotid catheters inserted, and GD19 MAP and pup weight, serum and tissues were collected. MAP in NP rats was 98.6 mmHg ± 4.71, 122.2 mmHg ± 1.84 in RUPPs which was improved to 110.789mmHg ± 1.23 in RUPP+SA. Circulating FoxP3+ Treg cells were 5.987% ± 1.69% of total T-cells population in NP, 0.77% ± 0.49% in RUPP rats but increased to 11.218% ± 2.9% in RUPP+SA; Circulating IL-6 levels were 41.008 ± 4.79 pg/mL in NP, 108.26 ± 25.99 pg/mL in RUPP, and 40.37 ± 4.49 pg/mL in RUPP+SA, Administration of the SA to the NP rats did not affect IL-6 Levels in comparison to NP at 36.79 ± 3.9 pg/mL. Plasma IL-10 Levels were at 58.399 ± 9.527 pg/mL in NP rats, these levels were significantly decreased in the RUPP rats, 26.298 ± 4.33 pg/mL, and treatment of the RUPPs with the SA significantly increased plasma IL-10 levels to 51.5486 ± 3.329 pg/mL. When the SA was given to NP rats, the levels for IL-10 were significantly higher compared to any of the other groups at 85.5207 ± 9.067 pg/mL. Placental Pre-pro Endothelin-1 (PPET-1) was increased 44.42 ± 0.269 fold in RUPP compared to NP 1 ± 0.255, but was decreased to 18.78 ± 0.48 in RUPP+SA. These data suggest an important role for up-regulating Treg cells to enhance the immune regulatory interactions and lower the hypertension without causing further reduction in fetal weight in response to placental ischemia during pregnancy.

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Progesterone induced blocking factor improves blood pressure, inflammation and pup weight in response to reduced uterine perfusion pressure (RUPP)

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.00152.2020 ◽

2021 ◽

Author(s):

Jesse N Cottrell ◽

Alexis Witcher ◽

Kyleigh M Comley ◽

Mark W Cunningham ◽

Tarek Ibrahim ◽

...

Keyword(s):

Blood Pressure ◽

Nk Cells ◽

Rat Model ◽

Perfusion Pressure ◽

Normal Pregnancy ◽

Th2 Cells ◽

Arterial Blood ◽

Blocking Factor ◽

Uterine Perfusion ◽

New Onset

Preeclampsia (PE) is characterized by new onset hypertension in association with elevated natural killer (NK) cells and inflammatory cytokines which are likely culprits for decreased fetal weight during PE pregnancies. As progesterone increases during normal pregnancy, it stimulates Progesterone Induced Blocking Factor (PIBF). PIBF has been shown to decrease inflammation and cytolytic NK cells, both of whichare increased during PE. We hypothesized that PIBF reduces inflammation as a mechanism to improve hypertension in the preclinical RUPP rat model of PE. PIBF (2.0 µg/mL) was administered intraperitoneally on gestational day 15 to either RUPP or normal pregnant (NP) rats. On day 18 carotid catheters were inserted. Mean arterial blood pressure (MAP) and samples were collected on day 19. MAP in NP rats (n=11) was 100±2 mmHg and 105±3 in NP+PIBF (n=8), 122±1 in RUPP rats (n=10), which improved to 110±2 mmHg in RUPP+PIBF rats (n=11), p<0.05. Pup weight was 2.4±0.1 grams (g) in NP, 2.5±0.1 g in NP+PIBF, 1.9±0.1 g in RUPP and improved to 2.1±0.1gin RUPP+PIBF rats. Circulating and placental cytolytic NK cells, IL-17 and IL-6 were significantly reduced while IL-4 and TH2 cells were significantly increased in RUPP rats after PIBF administration. Importantly, vasoactive pathways preproendothelin-1, nitric oxide and sFlt-1 were normalized in RUPP+PIBF rats compared to RUPP rats, p<0.05. Our findings suggest that PIBF normalized IL-4/TH2 cells which was associated with improved inflammation, fetal growth restriction and blood pressure in the RUPP rat model of PE.

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Serelaxin improves the pathophysiology of placental ischemia in the reduced uterine perfusion pressure rat model of preeclampsia

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.00192.2016 ◽

2016 ◽

Vol 311 (6) ◽

pp. R1158-R1163 ◽

Cited By ~ 19

Author(s):

Jose A. Santiago-Font ◽

Lorena M. Amaral ◽

Jessica Faulkner ◽

Tarek Ibrahim ◽

Venkata Ramana Vaka ◽

...

Keyword(s):

Nitric Oxide ◽

Rat Model ◽

Perfusion Pressure ◽

Resistance Index ◽

Hypertensive Disorder ◽

Pregnant Rats ◽

Tnf Α ◽

Uterine Perfusion ◽

Placental Ischemia ◽

Nitric Oxide Bioavailability

Preeclampsia is a hypertensive disorder of pregnancy that has limited therapeutic options. In healthy pregnancy, relaxin plays an important vasodilatory role to maintain vascular compliance; however, currently, there is no preclinical evidence to support the use of relaxin during preeclampsia. Therefore, the goal of this study was to test the hypothesis that recombinant human relaxin-2 (Serelaxin, Novartis; RLX) could reduce mean arterial pressure (MAP) and improve uterine artery resistance index (UARI) and nitric oxide bioavailability, and/or decrease prepro-endothelin-1 (PPET-1), soluble fms-like tyrosine kinase-1 (sFlt-1), and TNF-α) in the reduced uterine perfusion pressure (RUPP) model of preeclampsia. On day 14 of gestation (GD14), pregnant rats were assigned to normal pregnant (NP), RUPP, RUPP+RLX, or NP+RLX groups. Treated rats received RLX at 0.4 μg/h or RLX2 4 μg/h RLX via minipump implanted on GD14. On GD18, carotid arterial catheters were inserted, and on GD19, MAP and tissues were collected. MAP was increased in RUPP rats compared with NP but was lowered with either dose of RLX. UARI and sFlt-1 were significantly improved in both treated RUPP groups. Total circulating nitrate-nitrite improved and placental PPET-1 and TNF-α were significantly decreased with the higher dose of RLX. Renal cortex PPET-1 was reduced with both doses of RLX. In conclusion, Serelaxin improved blood pressure, sFlt-1, TNF-α, UARI, and nitric oxide bioavailability and PPET-1 in a rat model of preeclampsia, thereby suggesting a potential therapeutic role for RLX in maintaining maternal health and prolonging pregnancy in the face of placental ischemia.

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Abstract P267: Placental Ischemia Causes Cardiac Structural and Functional Abnormalities in the Reduced Uterine Perfusion Pressure Rat Model

Hypertension ◽

10.1161/hyp.70.suppl_1.p267 ◽

2017 ◽

Vol 70 (suppl_1) ◽

Author(s):

Bhavisha Bakrania ◽

Joey P Granger

Keyword(s):

Rat Model ◽

Perfusion Pressure ◽

Left Ventricular ◽

Inflammatory Factors ◽

Left Ventricular Ejection ◽

Maternal Circulation ◽

Ventricular Ejection Fraction ◽

Uterine Perfusion ◽

The Impact ◽

Placental Ischemia

Preeclampsia (PE) is a disorder prevalent in 5-7% of pregnancies. It is characterized by maternal hypertension and endothelial dysfunction. While it has been shown that systolic and diastolic function is impaired in women with PE, the exact mechanisms responsible for the cardiac dysfunction in PE have yet to be fully elucidated. PE is thought to develop in response to placental ischemia and ultimately the release of anti-angiogenic and pro-inflammatory factors into the maternal circulation. However, the impact of placental ischemia on cardiac function is unclear. Therefore the aim of this study was to assess cardiac structure and function in response to placental ischemia utilizing the Reduced Uterine Perfusion Pressure (RUPP) rat model. Briefly in this model, silver clips are placed on the abdominal aorta and branches of the ovarian arteries on gestational day (GD) 14 to induce placental ischemia. For this study, the RUPP ( n =8) group underwent surgery on GD 14, and both normal pregnant (NP, n =8) and RUPP rats had carotid catheters placed on GD 18. Blood pressure and echocardiography measurements, and tissue harvest were performed on GD 19. The RUPP group had significantly increased mean arterial pressure compared to the NP group on GD 19 (123±3 vs. 97±2 mmHg, P<0.01). RUPP rats had lower mean left ventricular ejection fraction (60±2 vs. 78±2 %, P<0.01) and fractional shortening (46±3 vs. 56±1 %, P=0.05), in addition to cardiac hypertrophy (0.97±0.04 vs. 0.91±0.02 g, P=0.02). These data were accompanied by increased cardiomyocyte surface area (348±36 vs. 289±23 μm 2 , P=0.03). In conclusion, this study shows that the RUPP rat develops cardiac structural and functional abnormalities after only five days of placental ischemia. Furthermore, these data suggest that the RUPP model could be useful in investigating and understanding the mechanisms which underpin these cardiac changes in PE patients.

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A model of preeclampsia in rats: the reduced uterine perfusion pressure (RUPP) model

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00117.2012 ◽

2012 ◽

Vol 303 (1) ◽

pp. H1-H8 ◽

Cited By ~ 98

Author(s):

Jing Li ◽

Babbette LaMarca ◽

Jane F. Reckelhoff

Keyword(s):

Intrauterine Growth Restriction ◽

Perfusion Pressure ◽

Trophoblast Invasion ◽

Maternal Circulation ◽

Pregnant Rats ◽

Renal Vasoconstriction ◽

Uterine Perfusion ◽

Placental Ischemia ◽

And Oxidative Stress ◽

New Onset

Preeclampsia is defined as new-onset hypertension with proteinuria after 20 wk gestation and is hypothesized to be due to shallow trophoblast invasion in the spiral arteries thus resulting in progressive placental ischemia as the fetus grows. Many animal models have been developed that mimic changes in maternal circulation or immune function associated with preeclampsia. The model of reduced uterine perfusion pressure in pregnant rats closely mimics the hypertension, immune system abnormalities, systemic and renal vasoconstriction, and oxidative stress in the mother, and intrauterine growth restriction found in the offspring. The model has been successfully used in many species; however, rat and primate are the most consistent in comparison of characteristics with human preeclampsia. The model suffers, however, from lack of the ability to study the mechanisms responsible for abnormal placentation that ultimately leads to placental ischemia. Despite this limitation, the model is excellent for studying the consequences of reduced uterine blood flow as it mimics many of the salient features of preeclampsia during the last weeks of gestation in humans. This review discusses these features.

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An increased population of regulatory T cells improves the pathophysiology of placental ischemia in a rat model of preeclampsia

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.00154.2015 ◽

2015 ◽

Vol 309 (8) ◽

pp. R884-R891 ◽

Cited By ~ 38

Author(s):

Denise C. Cornelius ◽

Lorena M. Amaral ◽

Ashlyn Harmon ◽

Kedra Wallace ◽

Alexia J. Thomas ◽

...

Keyword(s):

T Cells ◽

Regulatory T Cells ◽

Rat Model ◽

Perfusion Pressure ◽

Type I ◽

Pregnant Rats ◽

Tnf Α ◽

Uterine Perfusion ◽

Placental Ischemia ◽

One Way Anova

The reduced uterine perfusion pressure (RUPP) rat model of preeclampsia exhibits much of the pathology characterizing this disease, such as hypertension, inflammation, suppressed regulatory T cells (TRegs), reactive oxygen species (ROS), and autoantibodies to the ANG II type I receptor (AT1-AA) during pregnancy. The objective of this study was to determine whether supplementation of normal pregnant (NP) TRegs into RUPP rats would attenuate the pathophysiology associated with preeclampsia during pregnancy. CD4+/CD25+ T cells were isolated from spleens of NP and RUPP rats, cultured, and injected into gestation day (GD) 12 normal pregnant rats that underwent the RUPP procedure on GD 14. On GD 1, mean arterial pressure (MAP) was recorded, and blood and tissues were collected for analysis. One-way ANOVA was used for statistical analysis. MAP increased from 99 ± 2 mmHg in NP ( n = 12) to 127 ± 2 mmHg in RUPP ( n = 21) but decreased to 118 ± 2 mmHg in RUPP+NP TRegs ( n = 17). Circulating IL-6 and IL-10 were not significantly changed, while circulating TNF-α and IL-17 were significantly decreased after supplementation of TRegs. Placental and renal ROS were 339 ± 58.7 and 603 ± 88.1 RLU·min−1·mg−1 in RUPP and significantly decreased to 178 ± 27.8 and 171 ± 55.6 RLU·min−1·mg−1, respectively, in RUPP+NP TRegs; AT1-AA was 17.81 ± 1.1 beats per minute (bpm) in RUPP but was attenuated to 0.50 ± 0.3 bpm with NP TRegs. This study demonstrates that NP TRegs can significantly improve inflammatory mediators, such as IL-17, TNF-α, and AT1-AA, which have been shown to increase blood pressure during pregnancy.

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Reduced uterine perfusion pressure does not influence the endocannabinoid system (ECBS) transcripts in the rat model

Placenta ◽

10.1016/j.placenta.2013.06.083 ◽

2013 ◽

Vol 34 (9) ◽

pp. A27

Author(s):

Mauro Schenone ◽

Zorica Janjetovic ◽

Ramona Phinehas ◽

Brian Brocato ◽

Giancarlo Mari ◽

...

Keyword(s):

Rat Model ◽

Perfusion Pressure ◽

Endocannabinoid System ◽

Uterine Perfusion

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Preeclampsia: From Inflammation to Immunoregulation

Clinical Medicine Insights: Blood Disorders ◽

10.1177/1179545x17752325 ◽

2018 ◽

Vol 11 ◽

pp. 1179545X1775232 ◽

Cited By ~ 37

Author(s):

Denise C Cornelius

Keyword(s):

T Cells ◽

Rat Model ◽

The United States ◽

Therapeutic Interventions ◽

Trophoblast Invasion ◽

Positive Effects ◽

Immune Balance ◽

Uterine Perfusion ◽

Immune Imbalance ◽

Placental Ischemia

Preeclampsia (PE) affects 5% to 7% of pregnant women each year worldwide, accounts for up to 18% of maternal deaths in the United States each year, and is the number 1 cause of premature births. Preeclampsia is associated with hypertension after the 20th week of gestation with or without proteinuria, in conjunction with fetal growth restriction, maternal endothelial dysfunction, and chronic immune activation. The mechanisms leading to the development of PE are unclear. However, it is thought that shallow trophoblast invasion and insufficient remodeling of uterine spiral arteries result in placental ischemia. Consequently, an immune imbalance characterized by increases in proinflammatory CD4+ T cells and cytokines along with decreases in regulatory T cells and anti-inflammatory cytokines occurs. This imbalance leads to chronic inflammation and ensuing oxidative stress, proinflammatory cytokines, and autoantibodies. Studies performed in our laboratories, using the Reduced Uterine Perfusion Pressure (RUPP) rat model of placental ischemia, have demonstrated a role for this immune imbalance to mediate PE pathophysiology and identified potential mechanisms of immunoregulation that may be of benefit in the treatment of PE. Therefore, the purpose of this commentary is to review studies demonstrating the positive effects of immunoregulatory factors in the RUPP rat model of PE. Restoration of the immune balance in PE may be a potential strategy for the development of therapeutic interventions that could improve maternal and fetal outcomes associated with this maternal syndrome.

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Abstract P174: 17-hydroxyprogesterone Caproate Improves Blood Pressures and Placental Cytolytic Nk Cells in Response to Placental Ischemia During Pregnancy

Hypertension ◽

10.1161/hyp.68.suppl_1.p174 ◽

2016 ◽

Vol 68 (suppl_1) ◽

Author(s):

Lorena M Amaral ◽

Jamil Elfarra ◽

Denise C Cornelius ◽

Mark W Cunningham ◽

Tarek Ibrahim ◽

...

Keyword(s):

Nk Cells ◽

Premature Births ◽

Fetal Demise ◽

Hydroxyprogesterone Caproate ◽

Blood Pressures ◽

17 Hydroxyprogesterone ◽

Uterine Perfusion ◽

Placental Ischemia ◽

Do So ◽

New Onset

Preeclampsia (PE), new onset hypertension, is characterized by decreased fetal weight, elevated cytolytic natural killer (NK) cells and placental ischemia during pregnancy. Cytolytic NK are thought to play a role in fetal demise as they have also been shown to be increased in patients suffering from miscarriage.Currently, there is no effective treatment for PE except for early delivery, making PE the leading cause for premature births worldwide. Multiple injections of 17-hydroxyprogesterone caproate (17-OHPC) is used for prevention of preterm labor, but not for management of PE. We have shown that injections of 17-OHPC to the RUPP rat model of PE improves some but not all facets of PE observed in this model. Therefore this study was designed to test the hypothesis that injections of 17-OHPC on both day 15 (GD15) and GD (18) improve outcomes of hypertension in response to placental ischemia. To do so, 17-OHPC (3.32mg/kg) was administered intraperitoneally on GD 15 and 18 to reduced uterine perfusion pressure (RUPP) rats, carotid catheters were inserted on GD 18 and blood pressure (MAP) andplacental cytolytic NK cells were measured on GD 19. MAP in normal pregnant (NP) rats (n=8) was 104±4,119± 5 in RUPP rats (n=5) and 102±5 mmHgin RUPP+17-OHPC GD15 &18 (n=4), p <0.05.Total number of placental NK cells was 8.5± 3 in NP, 20±2 in RUPP rats, which decreased to 4.7± 3 % in RUPP+17-OHPC GD15 &18, p<0.05. Activated placental NK cells was 3.4± 1.6 in NP, 10.5±2.3 in RUPP, which improved to 2.7± 2.7 % in RUPP+17-OHPCGD15 & 18, p <0.05.In conclusion, administration of 17-OHPC on days 15 and 18 decreased hypertension and NK cells that are associated with PE in the RUPP ratand should be considered for addition to the management of PE.

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