The effects of sildenafil citrate on urinary podocin and nephrin mRNA expression in an L-NAME model of pre-eclampsia

Upregulation of SEMP1 Contributes to Improving the Biological Functions of Trophoblast via the PI3K/AKT Pathway in Preeclampsia

Disturbance of extravillous trophoblast infiltration is associated with preeclampsia (PE), a severe condition of pregnancy characterized by hypertension and proteinuria. Senescence-associated epithelial membrane protein 1 (SEMP1), an integral membrane protein, is a vital component of tight junction strands in epithelial or endothelial cells, with no clear function reported in PE. Gene Expression Omnibus (GEO) datasets showed that SEMP1 expression was downregulated in the placental tissues of PE patients, which was confirmed by assessing SEMP1 levels in placental samples collected in our hospital. Furthermore, less SEMP1 was detected in cytokeratin 7 positive trophoblast cells in the spiral arteries of rat placentas post L-arginine methyl ester hydrochloride (L-NAME) treatment. Trophoblast cells acquired robust ability of proliferation, migration, and invasion when SEMP1 was overexpressed. Such capability was weakened in SEMP1-silenced cells. Trophoblast cells overexpressing SEMP1 secreted more vascular endothelial growth factor A (VEGFA), which facilitated the tube formation of human umbilical vein endothelial cells. Blockade of PI3K/AKT signaling transduction with LY294002 dampened the effects of SEMP1 on trophoblast cells. Collectively, we firstly indicated that SEMP1 inhibition is a potential driver for PE, which may be associated with the deactivation of the PI3K/AKT pathway.

Pre-eclampsia

Pre-eclampsia is a life-threatening disease of pregnancy unique to humans and a leading cause of maternal and neonatal morbidity and mortality. Women who survive pre-eclampsia have reduced life expectancy, with increased risks of stroke, cardiovascular disease and diabetes, while babies from a pre-eclamptic pregnancy have increased risks of preterm birth, perinatal death and neurodevelopmental disability and cardiovascular and metabolic disease later in life. Pre-eclampsia is a complex multisystem disease, diagnosed by sudden-onset hypertension (>20 weeks of gestation) and at least one other associated complication, including proteinuria, maternal organ dysfunction or uteroplacental dysfunction. Pre-eclampsia is found only when a placenta is or was recently present and is classified as preterm (delivery <37 weeks of gestation), term (delivery ≥37 weeks of gestation) and postpartum pre-eclampsia. The maternal syndrome of pre-eclampsia is driven by a dysfunctional placenta, which releases factors into maternal blood causing systemic inflammation and widespread maternal endothelial dysfunction. Available treatments target maternal hypertension and seizures, but the only 'cure' for pre-eclampsia is delivery of the dysfunctional placenta and baby, often prematurely. Despite decades of research, the aetiology of pre-eclampsia, particularly of term and postpartum pre-eclampsia, remains poorly defined. Significant advances have been made in the prediction and prevention of preterm pre-eclampsia, which is predicted in early pregnancy through combined screening and is prevented with daily low-dose aspirin, starting before 16 weeks of gestation. By contrast, the prediction of term and postpartum pre-eclampsia is limited and there are no preventive treatments. Future research must investigate the pathogenesis of pre-eclampsia, in particular of term and postpartum pre-eclampsia, and evaluate new prognostic tests and treatments in adequately powered clinical trials.

Physiological characterization of an arginine vasopressin rat model of preeclampsia

Rodent models have contributed greatly to our understanding of preeclampsia (PE) progression in humans, however to-date no model has been able to effectively replicate the clinical presentation of the disease. This study aimed to provide a thorough physiological characterization of the arginine vasopressin (AVP)-induced rat model of PE to determine its applicability in studying the pathophysiology of PE. Female Sprague Dawley rats (n = 24) were separated into four groups (n = 6 per group) viz., pregnant AVP, pregnant saline, non-pregnant AVP, and non-pregnant saline. All animals received a continuous dose of either AVP (150 ng/h) or saline via subcutaneous mini osmotic pumps for 18 days. Full physiological characterization of the model included measuring systolic and diastolic blood pressure, and collecting urine and blood samples for biochemical analysis. AVP infusion significantly increased blood pressure and urinary protein levels in the pregnant rats (p < 0.05). Biochemical markers measured, differed significantly in the AVP-treated vs the pregnant saline groups (p < 0.05). Placental and individual pup weight decreased significantly in the pregnant AVP vs pregnant saline group (p < 0.05). The physiological and hematological data confirm the usefulness of this rat model in the study of PE, since AVP-induced vasoconstriction increases peripheral resistance and successfully mimics the pathological changes associated with PE development in humans.Abbreviations: PE: preeclampsia; AVP: arginine vasopressin; ISSHP: International Society for the Study of Hypertension in Pregnancy; ACOG: American College of Obstetricians and Gynecologists; RUPP: reduced uterine perfusion pressure; sFlt-1: soluble fms-like tyrosine kinase; VEGF: vascular endothelial growth factor; PlGF: placental growth factor; AVP: arginine vasopressin; PAVP: pregnant AVP-treated; PS: pregnant saline; GD: gestational day; ALT: alanine transaminase; NAVP: non-pregnant AVP-treated; NS: non-pregnant saline; AST: aspartate aminotransferase; HDL: high-density lipoprotein; RBC: red blood cell; RAAS: renin-angiotensin aldosterone system; HELLP: hemolysis, elevated liver enzymes, low platelet.

Juglanin protects against high fat diet-induced renal injury by suppressing inflammation and dyslipidemia via regulating NF-κB/HDAC3 signaling

Obesity is an important factor implicated in chronic kidney disease (CKD). Juglanin (Jug) is a natural compound extracted from the crude Polygonumaviculare, showing anti-inflammatory and anti-diabetic effects. However, whether Jug has protective effects against obesity-induced renal injury, little has been investigated. Herein, we attempted to explore the potential of Jug in mediating obesity-induced kidney disease in high fat diet (HFD)-challenged mice. Our results suggested that chronic HFD feeding markedly increased the body weights of mice compared to the ones fed with normal chow diet (NCD), along with significant glucose intolerance and insulin resistance. However, these metabolic disorders induced by HFD were effectively alleviated by Jug treatments in a dose-dependent manner. Moreover, HFD-challenged mice showed apparent histopathological changes in renal tissues with significant collagen accumulation, which were attenuated by Jug supplementation. In addition, Jug treatment decreased the expression levels of kidney injury molecule-1 (KIM-1), while increased nephrin and podocin expression levels in kidney of HFD-challenged mice, improving the renal dysfunction. Furthermore, HFD led to lipid deposition in kidney samples of mice by enhancing abnormal lipid metabolism. In addition, HFD promoted the releases of circulating pro-inflammatory cytokines, and enhanced the renal inflammation by activating nuclear factor-kappa B/histone deacetylase 3 (NF-κB/HDAC3) signaling. HFD-induced dyslipidemia and inflammation were considerably abrogated by Jug administration in mice. The protective effects of Jug against renal injury were confirmed in palmitate (PA)-stimulated HK2 cells in vitro mainly through suppressing the nuclear translocation of NF-κB and HDAC3, repressing inflammation and lipid accumulation eventually. Hence, Jug could ameliorate HFD-induced kidney injury mainly through blocking the NF-κB/HDAC3 nuclear translocation.

Fibroblast Growth Factor Type 2 (FGF2) Administration Attenuated the Clinical Manifestations of Preeclampsia in a Murine Model Induced by L-NAME

Background: In preeclampsia, a hypertensive disorder of pregnancy, the poor remodeling of spiral arteries leads to placental hypoperfusion and ischemia, provoking generalized maternal endothelial dysfunction and, in severe cases, death. Endothelial and placental remodeling is important for correct pregnancy evolution and is mediated by cytokines and growth factors such as fibroblast growth factor type 2 (FGF2). In this study, we evaluated the effect of human recombinant FGF2 (rhFGF2) administration in a murine model of PE induced by NG-nitro-L-arginine methyl ester (L-NAME) to test if rhFGF2 administration can lessen the clinical manifestations of PE.

Methods: Pregnant rats were administrated with 0.9% of NaCl (vehicle), L-NAME (60 mg/kg), FGF2 (666.6 ng/kg), L-NAME+FGF2 or L-NAME + hydralazine (10 mg/kg) from the 10th to 19th days of gestation. Blood pressure (BP), urine protein concentrations and anthropometric values both rat and fetuses were assessed. Histological evaluation of organs from rats delivered by cesarean section was carried out using hematoxylin and eosin staining.

Results: A PE-like model was established, and it included phenotypes such as maternal hypertension, proteinuria, and fetal growth delay. Compared to the groups treated with L-NAME, the L-NAME + FGF2 group was similar to vehicle: the BP remained stable and the rats did not develop enhanced proteinuria. Both the fetuses and placentas from rats treated with L-NAME + FGF2 had similar values of weight and size compared with the vehicle.

Conclusion: The intravenous administration of rhFGF2 showed beneficial and hypotensive effects, reducing the clinical manifestations of PE in the evaluated model.

Downregulation of Cullin 3 Ligase Signaling Pathways Contributes to Hypertension in Preeclampsia

Background: Preeclampsia (PE) is a leading cause of maternal and perinatal morbidity and mortality; however, its etiology and pathophysiology remain obscure. PE is initiated by inadequate spiral artery remodeling and subsequent placental ischemia/hypoxia, which stimulates release of bioactive factors into maternal circulation, leading to hypertension and renal damage. Methods and Results: Abundance of key components of cullin 3-ring ubiquitin ligase (CRL3), including cullin 3 (CUL3) and its neddylated modification, and adaptors including Kelch-like 2 (KLHL2) and Rho-related BTB domain containing protein 1 was all decreased in spiral arteries and placentas of PE patients. Similar changes were found in aortic tissues and renal distal tubules of pregnant mice treated with Nω-nitro-l-arginine methyl ester hydrochloride. The downregulation of CRL3 function led to accumulation of with-no-lysine kinases, phosphodiesterase 5, and RhoA in vessels and renal distal tubules, which promoted vasoconstriction and Na-Cl cotransporter activation in the distal convoluted tubule (DCT), as well as vascular and DCT structure remodeling. Proton pump inhibitor esomeprazole partially restored CRL3 function. In vitro studies have shown that increased abundance of JAB1, a component of the COP9 signalosome, inhibited CUL3 neddylation and promoted the expression of hypoxia-inducible factor 1α, which downregulated peroxisome proliferator-activated receptor γ and further promoted CUL3 inactivation. KLHL3/2 was degraded by increased autophagy. Conclusion: These findings support that the downregulation of CRL3 function disrupts the balance of vasoconstriction and vasodilation and aggravates excess reabsorption of sodium in PE.

Impact of Melatonin on Full-Term Fetal Brain Development and Transforming Growth Factor-β Level in a Rat Model of Preeclampsia

Preeclampsia (PE) is a leading cause of stroke and cognitive impairment in the offspring. Melatonin is involved in the outcome of normal pregnancy. Its receptors are widespread in the embryo. This study aimed to investigate the fetal neuroprotective effect of melatonin in experimentally induced PE. After induction of pregnancy in 18 female rats, they were divided into three equal groups. PE was induced in groups II and III by injection of deoxycorticosterone acetate and drinking isotonic saline. Melatonin was supplied to group III orally (10 mg/kg body weight) throughout pregnancy. Pregnancy was terminated on day 20, and macroanatomical investigation of three fetuses from each pregnant rat and their placentae was performed. Placental and brain homogenates were analyzed for malondialdehyde (MDA), placental growth factor (PLGF), tumor necrosis factor-α (TNF-α), and brain transforming growth factor-β (TGF-β). Histopathological analysis of fetal brain sections was performed. Melatonin improved placental, fetal, and brain weight; significantly reduced fetal death rate; significantly increased PLGF, placental and brain superoxide dismutase, and brain TGF-β; and significantly decreased placental TNF-α and brain MDA. Brain micromorphological study found normal glial cells and neuropil in the melatonin-treated group and a loss of neuronal cell outlines with an accumulation of cellular debris in the untreated group. In conclusion, melatonin approximately showed a neuroprotective activity by managing PE-induced oxidative stress in the placenta and fetal cerebral cortex of rats.

Apocynin inhibits placental TLR4/NF-κB signaling pathway and ameliorates preeclampsia-like symptoms in rats

OBJECTIVE

We aimed to investigate the potency of apocynin in ameliorating preeclampsia and explore the underlying mechanisms.

METHODS

Preeclampsia model was constructed in rats by administering 200 mg/kg/day L-NAME. Apocynin was given orally in drinking water. Systolic blood pressure and proteinuria were monitored during treatment. Survival rate rate of the pups and placental weight were assessed. Serum sFlt-1, PIGF, IL-6 and placental TLR4 levels were measured using ELISA or qRT-PCR.

RESULTS

Apocynin dose-dependently decreased systolic blood pressure and proteinuria during gestation. Survival rate of the pups and placental weight were improved by apocynin treatment. Apocynin ameliorated the imbalance of sFlt-1 and PIGF in serum and placenta of rats with preeclampsia. Apocynin attenuated serum inflammatory cytokine expression and placental inflammation most likely due to downregulation of the placental TLR4/NF-kB pathway in L-NAME treated rats.

CONCLUSIONS

Apocynin potently ameliorates the L-NAME-induced preeclampsia, which is achieved by re-balancing the sFlt-1 and PIGF levels, attenuating inflammation, and inhibiting TLR4/NF-κB p65 signaling.

Podocytes-The Most Vulnerable Renal Cells in Preeclampsia

Preeclampsia (PE) is a disorder that affects 3–5% of normal pregnancies. It was believed for a long time that the kidney, similarly to all vessels in the whole system, only sustained endothelial damage. The current knowledge gives rise to a presumption that the main role in the development of proteinuria is played by damage to the podocytes and their slit diaphragm. The podocyte damage mechanism in preeclampsia is connected to free VEGF and nitric oxide (NO) deficiency, and an increased concentration of endothelin-1 and oxidative stress. From national cohort studies, we know that women who had preeclampsia in at least one pregnancy carried five times the risk of developing end-stage renal disease (ESRD) when compared to women with physiological pregnancies. The focal segmental glomerulosclerosis (FSGS) is the dominant histopathological lesion in women with a history of PE. The kidney’s podocytes are not subject to replacement or proliferation. Podocyte depletion exceeding 20% resulted in FSGS, which is a reason for the later development of ESRD. In this review, we present the mechanism of kidney (especially podocytes) injury in preeclampsia. We try to explain how this damage affects further changes in the morphology and function of the kidneys after pregnancy.

Melatonin attenuates hypertension and oxidative stress in a rat model of L-NAME-induced gestational hypertension

Preeclampsia is a life-threatening multiorgan systemic disease with manifestations including gestational hypertension, oxidative stress, and vascular dysfunction. We aimed to evaluate the therapeutic effects of melatonin on an L-NAME (NLG-nitro-l-arginine methyl ester)-induced rat preeclampsia model. During gestation, L-NAME was added to drinking water at 50 mg/kg/day from gestation day (GD) 8. Rats received the combination of L-NAME with melatonin (10 mg/kg/day), or aspirin (1.5 mg/kg/day), and rats that received only L-NAME or no treatments were used as controls. Aspirin was mixed with rodent chow and melatonin was administered intraperitoneally. Blood pressure and urine protein content were monitored every 3 days. On GD19, blood samples were collected for biochemical analysis. Compared to untreated L-NAME rats, melatonin led to markedly lowered blood pressure and urine protein content, and recovery in the fetus alive ratio, fetal weight, and the fetal weight/placental weight ratio. Compared to untreated L-NAME rats, plasma antioxidant capacity and plasma malondialdehyde were increased and decreased by melatonin, respectively, in L-NAME rats. Melatonin treatment also reduced sFlt-1, increased PlGF, and decreased the sFlt-1/PlGF ratio. In the placenta, melatonin also reduced sFlt-1 levels and increased Nrf2, PlGF, and HO-1 levels. We have demonstrated in a rat model of preeclampsia that melatonin exerts significant protective effects through lowering blood pressure and reducing oxidative stress.

Current Concepts on the Reno-Protective Effects of Phosphodiesterase 5 Inhibitors in Acute Kidney Injury: Systematic Search and Review

Acute kidney injury (AKI) is associated with increased morbidity, prolonged hospitalization, and mortality, especially in high risk patients. Phosphodiesterase 5 inhibitors (PDE5Is), currently available as first-line therapy of erectile dysfunction in humans, have shown a beneficial potential of reno-protection through various reno-protective mechanisms. The aim of this work is to provide a comprehensive overview of the available literature on the reno-protective properties of PDE5Is in the various forms of AKI. Medline was systematically searched from 1946 to November 2019 to detect all relevant animal and human studies in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement. In total, 83 studies were included for qualitative synthesis. Sildenafil is the most widely investigated compound (42 studies), followed by tadalafil (20 studies), icariin (10 studies), vardenafil (7 studies), zaprinast (4 studies), and udenafil (2 studies). Even though data are limited, especially in humans with inconclusive or negative results of only two clinically relevant studies available at present, the results of animal studies are promising. The reno-protective action of PDE5Is was evident in the vast majority of studies, independently of the AKI type and the agent applied. PDE5Is appear to improve the renal functional/histopathological alternations of AKI through various mechanisms, mainly by affecting regional hemodynamics, cell expression, and mitochondrial response to oxidative stress and inflammation.

Animal Models of Preeclampsia: Causes, Consequences, and Interventions

Preeclampsia is a common pregnancy complication, affecting 2% to 8% of pregnancies worldwide, and is an important cause of both maternal and fetal morbidity and mortality. Importantly, although aspirin and calcium are able to prevent preeclampsia in some women, there is no cure apart from delivery of the placenta and fetus, often necessitating iatrogenic preterm birth. Preclinical models of preeclampsia are widely used to investigate the causes and consequences of preeclampsia and to evaluate safety and efficacy of potential preventative and therapeutic interventions. In this review, we provide a summary of the published preclinical models of preeclampsia that meet human diagnostic criteria, including the development of maternal hypertension, together with new-onset proteinuria, maternal organ dysfunction, and uteroplacental dysfunction. We then discuss evidence from preclinical models for multiple causal factors of preeclampsia, including those implicated in early-onset and late-onset preeclampsia. Next, we discuss the impact of exposure to a preeclampsia-like environment for later maternal and progeny health. The presence of long-term impairment, particularly cardiovascular outcomes, in mothers and progeny after an experimentally induced preeclampsia-like pregnancy, implies that later onset or reduced severity of preeclampsia will improve later maternal and progeny health. Finally, we summarize published intervention studies in preclinical models and identify gaps in knowledge that we consider should be targets for future research.

Reductions of Circulating Nitric Oxide are Followed by Hypertension during Pregnancy and Increased Activity of Matrix Metalloproteinases-2 and -9 in Rats

Hypertensive pregnancy has been associated with reduced nitric oxide (NO), bioavailability, and increased activity of matrix metalloproteinases (MMPs). However, it is unclear if MMPs activation is regulated by NO during pregnancy. To this end, we examined activity of MMP-2 and MMP-9 in plasma, placenta, uterus and aorta, NO bioavailability, oxidative stress, systolic blood pressure (SBP), and fetal-placental development at the early, middle, and late pregnancy stages in normotensive and Nω-Nitro-L-arginine methyl-ester (L-NAME)-induced hypertensive pregnancy in rats. Reduced MMP-2 activity in uterus, placenta, and aorta and reduced MMP-9 activity in plasma and placenta with concomitant increased NO levels were found in normotensive pregnant rats. By contrast, increased MMP-2 activity in uterus, placenta, and aorta, and increased MMP-9 activity in plasma and placenta with concomitant reduced NO levels were observed in hypertensive pregnant rats. Also, elevated oxidative stress was displayed by hypertensive pregnant rats at the middle and late stages. These findings in the L-NAME-treated pregnant rats were also followed by increases in SBP and associated with fetal growth restrictions at the middle and late pregnancy stages. We concluded that NO bioavailability may regulate MMPs activation during normal and hypertensive pregnancy.

Hypertension, augmented activity of matrix metalloproteinases-2 and -9 and angiogenic imbalance in hypertensive pregnancy are attenuated by doxycycline

Preeclampsia is manifested as maternal hypertension and fetal growth restriction. Matrix metalloproteinases (MMPs) are involved in hypertension and doxycycline reduces blood pressure by inhibition of MMPs. Moreover, excessive levels of MMPs and reduced nitric oxide (NO) bioavailability have been related to preeclampsia. We investigated the involvement of MMPs in hypertension in pregnancy induced by Nω-Nitro-L-arginine methyl ester (L-NAME) in rats. To this end, zimography was performed to evaluate the activity of MMPs -2 and -9 in placenta, uterus and thoracic aorta, and systolic blood pressure, feto-placental development and metabolites of NO were evaluated. Also, plasma antioxidant capacity, plasma levels of soluble fms-like tyrosine kinase-1 (sFlt-1) and placental growth factor (PLGF) were examined. Doxycycline prevented hypertensive pregnancy and significant reductions in number of pups induced by L-NAME. Low NO bioavailability was found in hypertensive pregnant rats treated (or not) with doxycycline. Increased activity of placental MMP-2 and MMP-9 and uterine MMP-2 were attenuated by doxycycline. MMP-2 activity of thoracic aorta showed no change after hypertension. Increases in PLGF with concomitant decreases in sFlt-1 levels were found with doxycycline treatment. Also, plasma antioxidant capacity was improved with doxycycline. Also, elevations of plasma antioxidant capacity were observed in hypertensive rats treated with doxycycline. Therefore, we suggest that L-NAME reduced NO and this triggered the increases in MMP-2 and -9 activities during hypertensive pregnancy. Importantly, increases in MMPs activation and angiogenic imbalance were attenuated by doxycycline and these effects were associated with decreases in systolic blood pressure.

Silencing of Annexin A1 suppressed the apoptosis and inflammatory response of preeclampsia rat trophoblasts

Preeclampsia (PE) is a disorder that is characterized by pregnancy-induced hypertension. It has been reported that Annexin A1 (ANXA1) is highly expressed in the plasma of women diagnosed with PE. Therefore, the present study aimed to examine the effect of ANXA1 on PE rats. The PE animal model was constructed in rats using Nω-nitro-L-arginine methyl ester (L-NAME), and the blood pressure and urine protein levels of rats were detected. The pathological features of placental tissue, and the levels of inflammatory factors and ANXA1 were respectively measured by hematoxylin-eosin staining, enzyme-linked immunosorbent assay and immunohistochemical assay. The activity of trophoblasts obtained from PE placental tissue was measured using immunofluorescence staining, while cell apoptosis was assessed using flow cytometry. The levels of associated factors were determined by reverse transcription-quantitative polymerase chain reaction and western blot analysis. The results identified that systolic blood pressure, diastolic blood pressure, mean arterial pressure and urine protein levels were enhanced, and that the contents of ANXA1, tumor necrosis factor alpha (TNF-α), interleukin (IL)-1β, IL-6 and IL-8 were increased in the L-NAME group. Transfection with small interfering RNA (siRNA)-ANXA1 markedly decreased the apoptosis and inflammatory response of trophoblasts. In addition, siRNA-ANXA1 upregulated the levels of B-cell lymphoma-2 (Bcl-2) and pro-caspase-3, and downregulated the levels of Bcl-2-associated X protein, cleaved-caspase-3, TNF-α, IL-1β, IL-6 and IL-8. Furthermore, siRNA-ANXA1 repressed the phosphorylation of Janus kinase 2 (JAK2) and signal transducer and activator of transcription 3 (STAT3); however, siRNA-ANXA1 did not alter the levels of JAK2 and STAT3. Therefore, silencing of ANXA1 suppressed the apoptosis and inflammatory response of PE rat trophoblasts, and downregulated JAK2/STAK3 pathway.

Erzhi Formula Extracts Reverse Renal Injury in Diabetic Nephropathy Rats by Protecting the Renal Podocytes

Podocytes injury was a crucial factor resulting in diabetic nephropathy (DN). Erzhi formula extract (EZF) was a clinical effective Chinese medicine on DN, but its mechanism was unclear. In this study, the main compounds of EZF and their pharmacokinetics in rat were detected by HPLC-MS/MS. And then, blood glucose, urine protein, renal index, renal microstructural (HE/PAS staining), inflammatory factors (IL-β, TNF-α, IL-6), and protein/mRNA expression related to the function of podocyte (CD2AP and Podocin) in DN rats were investigated after the oral administration of EZF. The concentrations of specnuezhenide and wedelolactone in rat kidney were 7.19 and 0.057 mg/kg, respectively. The T_max of specnuezhenide and wedelolactone were 2.0 and 1.50 h, respectively. Their C_max were, respectively, 30.24 ± 2.68 and 6.39 ± 0.05 μg/L. Their AUC_(0-∞) were 123.30 ± 2.68 and 16.56 ± 0.98 μg/L⁎h, respectively. Compared with the model group, the blood glucose and the 24-hour urinary protein were significantly decreased (P < 0.05) after 16 weeks' treatment of EZF. The expressions of Podocin and CD2AP protein/mRNA were increased (P < 0. 05). The deteriorate of glomerular morphology was alleviated under the treatment of EZF. EZF prominently decreased the levels of inflammatory factors (P < 0.05). MDA was significantly decreased (P < 0.05) with the significant increase of SOD activity (P < 0.05) in EZF groups. All the results proved that EZF repaired glomerular mesangial matrix, protected renal tubule, and improved renal function in DN rats by upregulating the expression of Podocin and CD2AP protein/mRNA in podocytes.

Phosphodiesterase Inhibition in the Treatment of Preeclampsia: What Is New?

PURPOSE OF REVIEW

The present study intends to review the possibility of using phosphodiesterase inhibitors as a treatment option for preeclampsia, addressing potential risks and benefits.

RECENT FINDINGS

Preeclampsia is the most common hypertensive disorder of pregnancy, often responsible for severe maternal and fetal complications, which can lead to early pregnancy termination and death. Despite the numerous studies, its pathophysiology is still unclear, although it seems to involve a multiplicity of complex factors related to angiogenesis, ineffective vasodilation, oxidative stress, inflammatory cytokines, and endothelial dysfunction. It has been hypothetically suggested that the use of phosphodiesterase inhibitors is capable of improving placental and fetal perfusion, contributing to gestational scenario, by decreasing the symptomatology and severity of this syndrome. In this literature review, it has been found that most of the studies were conducted in animal models, and there is still lack of evidence supporting its use in clinical practice. Research in human indicates conflicting findings; randomized controlled trials were scarce and did not demonstrate any benefit in morbidity or mortality. Data regarding to pathophysiological and interventional research are described and commented in this review. The use of phosphodiesterase inhibitors in the treatment of preeclampsia is controversial and should not be encouraged taking into account recent data.

Tadalafil Improves L-NG-Nitroarginine Methyl Ester-Induced Preeclampsia With Fetal Growth Restriction-Like Symptoms in Pregnant Mice

BACKGROUND

We investigated the efficacy and mechanisms of tadalafil, a selective phosphodiesterase 5 inhibitor, in treating preeclampsia (PE) with fetal growth restriction (FGR) using L-NG-nitroarginine methyl ester (L-NAME)-induced PE with FGR in pregnant mice as our experimental model.

METHODS

C57BL/6 mice were divided into 2 groups 11 days postcoitum (d.p.c.). A control group of dams (C dam) received 0.5% carboxymethylcellulose (CMC). A L-NAME-treated group received 1 mg/ml L-NAME dissolved in CMC. The L-NAME-treated dams were divided into 2 subgroups 13 d.p.c. One subgroup continued to receive L-NAME (L dams). The other subgroup received L-NAME with 0.08 mg/ml tadalafil suspended in CMC (TL dams). Maternal systolic blood pressure (SBP) and proteinuria were assessed 16 d.p.c. Fetal weight was recorded, and placentas and maternal kidneys were collected 17 d.p.c.

RESULTS

Maternal SBP, proteinuria, and fetal weight were improved for TL dams compared to L dams. The placental concentration of placental growth factor (PlGF) was higher for TL dams than for the C and L dams. The placental maternal blood sinuses of L dams were narrower than those of C dams, but those of TL dams improved to a similar width as C dams. Glomerular oxidative stress was ameliorated in TL dams compared to L dams.

CONCLUSIONS

Tadalafil dilates the placental maternal blood sinuses, which leads to increase PlGF production, and contributes to facilitate fetal growth and improve maternal SBP. Moreover, tadalafil ameliorates glomerular damage by reducing oxidative stress. These results suggest that tadalafil is a candidate for treatment of PE with FGR.

The mechanism of attenuation of epithelial-mesenchymal transition by a phosphodiesterase 5 inhibitor via renal klotho expression

Phosphodiesterase-5 (PDE-5) inhibitors induces vasodilation in several organs by blocking cyclic GMP (guanosine monophosphate) degradation. However, the existence of alternative mechanism of action in case of an impaired nitric oxide (NO) system remains controversial. Previous studies suggested that decreased NO bioavailability may result in the downregulation of klotho expression, but the relationship between klotho and NO remains obscure. Therefore, we investigated whether a PDE-5 inhibitor could preserve epithelial-mesenchymal transition (EMT) and relationship exists between the NO and renal klotho expression. Ten-week-old SD rats (N = 24, 200 g, male) were divided (N = 6) into four groups, which received: A LSD, L-NAME 1 mg/mL in drinking water, Udenafil 5 mg/kg subcutaneously and both for 4 weeks. Urine nitrate/nitrite, NGAL (Neutrophil gelatinase-associated lipocalin), and cGMP were measured using ELISA. Kidney was subjected to evaluate PCNA (proliferative cell nuclear antigen), α-SMA (smooth muscle cell antigen), E-cadherin, and klotho expression. Urine cGMP decreased after treatment of PDE-5 inhibitor compared with control due to blocking degradation of cGMP (P < .05, control vs Udenafil and L-NAME with Udenafil groups). Urine NGAL increased after treating of L-NAME and attenuated after using PDE-5 inhibitor (P < .05, control vs L-NAME and L-NAME with Udenafil). PCNA, α-SMA, and E-cadherin (EMT markers) increased after L-NAME treatment and normalized after using PDE-5 inhibitor. Klotho expression showed trend to increase in the L-NAME with PDE-5 inhibitor group compared with the L-NAME group, however, eNOS expression did not change after treatment of L-NAME or PDE-5 inhibitor compared with control. PDE-5 inhibitor alleviates EMT in the kidney via klotho modulation independent of the NO system.