nephrin and Pre-Eclampsia

Early detection of pre-eclampsia remains one of the major focuses of antenatal obstetric care. There is often a delay in the diagnosis, mainly due to the non-specific nature of the condition. Podocytes which play a pivotal role in glomerular function become injured in pre-eclampsia leading to subsequent proteinuria. Our aim was to review available studies to determine the clinical utility of biomarkers of podocyte injury in pre-eclampsia.. We used QUADAS (Quality Assessment of Diagnostic Accuracy Studies) criteria to perform a systematic review of the literature to determine the clinical utility of podocyte injury biomarkers in predicting pre-eclampsia.. This study identified five potential renal biomarkers including podocytes, nephrin, synaptopodin, podocin and podocalyxin. The pooled sensitivity of all biomarkers was 0.78 (95% CI 0.74-0.82) with a specificity of 0.82 (95% CI 0.79-0.85). The area under the Summary of Receiver Operating Characteristics Curve (SROC) was 0.926 (SE 0.30). Urinary nephrin achieved the highest diagnostic values with a sensitivity of 0.81 (95% CI 0.72-0.88) and specificity of 0.84 (95% CI 0.79-0.84).. Biomarkers of glomerular injury show promise as diagnostic aids in pre-eclampsia. A large-scale prospective cohort study is warranted before these biomarkers can be recommended for routine clinical care.

Topics: Biomarkers; Case-Control Studies; Female; Glomerular Filtration Barrier; Humans; Kidney Glomerulus; Membrane Proteins; Podocytes; Pre-Eclampsia; Pregnancy; Proteinuria; ROC Curve; Sensitivity and Specificity; Sialoglycoproteins

Nephrin, the main structural protein of the slit diaphragm, is expressed on the surface of glomerular podocytes and is critical in maintaining permselectivity and preventing proteinuria. This review focuses on the fate of nephrin in the context of endothelial injury and gives an update on the recent progress in understanding the pathomechanisms that lead to proteinuria.. The following conditions of endothelial injury were found to induce loss of nephrin.(1) Preeclampsia, in which the associated proteinuria is induced by the soluble variant of vascular endothelial growth factor, which stimulates production of endothelin 1 (ET1) in endothelial cells. ET1 in turn triggers nephrin shedding from podocytes.(2) Hypertension, in which increased levels of angiotensin II induce podocyte apoptosis and reduce nephrin expression, leading to proteinuria in rats.(3) Diabetes and high fat diet, which lead to a significant increase in inflammatory molecules and cytokines, including MCP-1, which induces changes in podocyte cytoskeleton and nephrin loss.. Recent results showed that damage to endothelial cells may alter endothelial-podocyte interaction and induces nephrin loss, a main cause of proteinuria.

Topics: Animals; Diabetic Nephropathies; Dietary Fats; Endothelial Cells; Endothelium; Female; Humans; Hypertension; Kidney; Kidney Glomerulus; Membrane Proteins; Podocytes; Pre-Eclampsia; Pregnancy; Signal Transduction

Nephrin is a protein in the glomerular podocyte slit diaphragm; therefore, its presence in urine implies damage to podocytes. This study aimed to determine the usefulness of nephrin as a biomarker in maternal urine to predict preeclampsia (PE).. This prospective study included pregnant women admitted for delivery at Seoul National University Bundang Hospital from March 2019 to May 2020. Patients who had been diagnosed with PE were included, and patients without a history of underlying diseases were recruited for the control group. Pertinent clinical data were collected. Urine samples were obtained, and nephrin signaling was detected through test strips using a lateral flow assay. The point-of-care test results were compared between patients with PE and without (control group), using the exact concentration of nephrin by enzyme-linked immunosorbent assay.. Clinical characteristics - maternal age, parity, proportion of twin pregnancies, height, weight, and cesarean delivery rate - were comparable between the PE and control groups. Nephrin signals were classified into four groups. In the PE group, signals 0, 1, 2, and 3 were found in 18.4% (9/49), 44.9% (22/49), 24.5% (12/49), and 12.2% (6/49) of participants, respectively. Results were significantly different in the control group, in which 84.3% (43/51) were found to have signal 0 (p < 0.001).. Nephrin signaling in maternal urine could be a noninvasive and useful test for early detection of severity of PE.

Topics: Female; Humans; Membrane Proteins; Podocytes; Pre-Eclampsia; Pregnancy; Prospective Studies

The main objective of this study is to investigate the association of the NPHS1 gene polymorphisms (rs437168) and ACTN4 (rs3745895) in the pathogenesis of PE in women of African Ancestry.. 637 blood samples, normotensive pregnant (n = 280) and pre-eclampsia (n = 357) were included. The PE group was sub-divided into early onset pre-eclampsia (n = 187) and late onset pre-eclampsia (n = 170). rs74315346, rs869025495, rs121908415, rs3745895, and rs437168 were genotyped from isolated DNA using real time PCR.. This study found that the C allele of rs437168 is significantly associated with the pathogenesis of early onset PE and may be accountable for renal injury, which is a risk factor for the development of EOPE in women of African Ancestry.

Topics: Actinin; Alleles; Black People; Case-Control Studies; Female; Genotype; Humans; Membrane Proteins; Polymorphism, Single Nucleotide; Pre-Eclampsia; Pregnancy; Risk Factors

Pre-eclampsia (PE) is characterized by new-onset hypertension and proteinuria. Damage of podocyte cells has been reported in pre-eclamptic women, thus podocyte specific proteins such as nephrin and podocalyxin could be useful biomarkers in PE.. To investigate the role of urinary nephrin (u-nephrin) and urinary podocalyxin (u-PDX) levels in predicting PE in women with a high-risk pregnancy.. We included 101 pregnant women in this study and allocated them into three groups: group 1 included pregnant women at high risk of developing PE (n=41), group 2 - pregnant women with PE (n=30), and group 3 was the controls including healthy pregnant women (n=30). The inclusion criteria for women with PE were de novo hypertension >140/90 mm Hg, proteinuria >300 mg/24 hours, and presence of edema after 20 weeks of gestation, while the exclusion criteria were a history of renal diseases and pregnant women younger than 18. Inclusion criteria for the group of women with a high-risk pregnancy was gestational week >15, a history of PE in a previous pregnancy, pre-existing diabetes type 1 or 2, pre-existing hypertension, multiple gestations, prior placental abruption, obesity women, nulliparity, maternal age >35 years, and a family history of PE. The study was conducted from March 2016 to May 2017 in the Medical Faculty at the Institute of Medical and Experimental Biochemistry in Skopje. Urine samples were used to measure the nephrin and podocalyxin levels using immunoenzyme assay, creatinine and microalbumin. Blood samples were collected for biochemical analyses.. U-nephrin levels were elevated in 96.7% of women with PE, and 73% of women with a high-risk pregnancy. U-PDX levels were elevated in 63% of the women with PE and 100% of the women with a high-risk pregnancy. U-nephrin and u-PDX levels were significantly increased in women with a high-risk pregnancy and women with PE compared with a control group (p.

Topics: Adult; Biomarkers; Female; Humans; Hypertension; Membrane Proteins; Placenta; Pre-Eclampsia; Pregnancy; Pregnant Women; Proteinuria; Sialoglycoproteins

Topics: Actins; Adult; Angiotensin I; Animals; Blood Pressure; Cell Line; Down-Regulation; Female; Humans; Hypertension, Pregnancy-Induced; Membrane Proteins; Mice; Peptide Fragments; Podocytes; Pre-Eclampsia; Pregnancy; Proteinuria; Proto-Oncogene Mas; Proto-Oncogene Proteins; Receptors, G-Protein-Coupled; Renin-Angiotensin System; Zonula Occludens-1 Protein

Pre-eclampsia (PE) is closely associated with perinatal morbidity and mortality and we want to investigate tetramethylpyrazine (TMP)'s effects on PE. Pregnant Sprague-Dawley rats were randomly divided into five groups: normal pregnant (PC), PE, PE+TMP 20 mg/kg, PE+TMP 40 mg/kg, and PE+TMP 60 mg/kg group. The PE rat model was established via L-NAME treatment. Systolic blood pressures (SBP) and urinary protein concentration were detected via the tail-cuff method and CBB kit, respectively. mRNA levels of key genes were analyzed via quantitative PCR and protein levels of key genes were measured by ELISA or western blot. TMP decreased SBP and urinary protein concentration of PE rats. TMP inhibited L-NAME-induced decrease in pups alive ratio, pups weight, and the ratio of pups/placenta weight and reversed L-NAME induced changes in placental histology, whereas it had little effect on placental weight. Urinary nephrin and podocin expressions were enhanced and serum placental growth factor level was decreased in PE rats, whereas TMP inhibited the above phenomena. TMP suppressed L-NAME-induced sFlt-1 upregulation in serums and kidneys of PE rats, whereas it downregulated IL-6 and MCP-1 expression in PE rats' serums, placentas and kidneys. TMP also suppressed the increase in placental sFlt-1 and vascular endothelial growth factor level caused by L-NAME. In addition, TMP inhibited CHOP and GRP78 expressions and decreased the ratio of p-elF2α/elF2α in PE rats. TMP attenuated the consequences of NO inhibition in pregnant rats.

Topics: Animals; Blood Pressure; Disease Models, Animal; Endoplasmic Reticulum Chaperone BiP; Female; Gene Expression Regulation; Heat-Shock Proteins; Humans; Intracellular Signaling Peptides and Proteins; Membrane Proteins; NG-Nitroarginine Methyl Ester; Nitric Oxide; Placenta; Pre-Eclampsia; Pregnancy; Pyrazines; Rats; Transcription Factor CHOP; Vascular Endothelial Growth Factor Receptor-1

Preeclampsia is reported in pregnant women around the world and often causes maternal/fetal mortality and morbidity. In the current study, we assessed the efficacy of celastrol on a rat preeclampsia model induced by N

Topics: Animals; Female; Intracellular Signaling Peptides and Proteins; Kidney; Matrix Metalloproteinase 9; Matrix Metalloproteinase Inhibitors; Membrane Proteins; NG-Nitroarginine Methyl Ester; Pentacyclic Triterpenes; Placenta Growth Factor; Pre-Eclampsia; Pregnancy; Rats, Sprague-Dawley; RNA, Messenger; Triterpenes; Vascular Endothelial Growth Factor Receptor-1

Topics: Adult; Biomarkers; Cell Hypoxia; Cell Line; Cells, Cultured; Female; Humans; Membrane Glycoproteins; Membrane Proteins; Podocytes; Pre-Eclampsia; Pregnancy; Superoxide Dismutase

This study aimed to explore the correlation between microRNA-155 (miR-155), interleukin 17A (IL-17), and late preeclampsia (PE) using biochemical parameters in maternal serum and urine.. Sixty patients with PE were recruited to this study and were divided into 3 groups according to levels of urinary protein: mild urinary protein group (group A); moderate urinary protein group (group B); and severe urinary protein group (group C). All subjects presented with late onset PE (≥32 weeks). In addition, 20 healthy pregnant women were recruited as a normal group (NP). Maternal serum and urine samples were obtained from all participants and assayed using immunofluorescence, transmission electron and immune electron microscopy, and western blot. Furthermore, placentas were also collected and miR-155 and IL-17 expression was measured using an enzyme-linked immunosorbent assay.. Levels of miR-155 and IL-17 expression were found to be increased in PE placentas and serum, compared to the normal group (P <.05). IL-17 levels and podocytes had a positive association in the serum of patients with PE. In addition, over-expression of miR-155 resulted in increased IL-17 production by CD4+ T cells in vitro, and nephrin expression was decreased in podocytes. Furthermore, IL-17 reduced nephrin expression in podocytes and podocyte apoptosis in a dose and time-dependent manner.. The results of this study demonstrate a correlation between miR-155 and IL-17 in the formation of proteinuria during late onset PE.

Topics: Apoptosis; Biomarkers; Birth Weight; CD4 Antigens; Cells, Cultured; Coculture Techniques; Female; Humans; Interleukin-17; Lymphocytes; Membrane Proteins; MicroRNAs; Placenta; Podocytes; Pre-Eclampsia; Pregnancy; Pregnancy Trimester, Third; Proteinuria; Severity of Illness Index

Urine podocin mRNA expression and urine podocin : nephrin mRNA expression ratio (PNR) increase with increasing proteinuria during pregnancy complicated with pre-eclampsia (PE). This suggests that urine podocytes with reduced nephrin mRNA expression are abundant in pathological podocyturia. The aim of this study was therefore to determine post-partum changes in podocyturia and PNR in relation to proteinuria after pre-eclampsia (PE).. A total of 137 peripartum urine specimens, consisting of 72 and 65 from 24 and 30 women with PE and normotensive control pregnancies (NCP), respectively, were studied. Determination of urine protein and creatinine concentration and quantitative analysis of podocyte-specific podocin and nephrin mRNA expression were carried out using reverse transcription-polymerase chain reaction in pelleted urine samples. Podocyturia was monitored via urine podocin mRNA expression. Podocyturia and proteinuria were normalized by urine creatinine concentration.. Podocyturia and urine PNR decreased with decreasing proteinuria as well as with increasing time after delivery in the urine from PE women. In physiological proteinuria (i.e. protein : creatinine ratio [P/Cr] 0.005-0.1 mg/mg), however, both podocyturia and PNR were significantly greater in the urine from PE women compared with NPC women, although P/Cr was similar between the groups (median, 0.037 mg/mg for PE vs 0.029 mg/mg for NCP).. Podocyturia decreases with decreasing proteinuria in PE women after childbirth. In PE women, however, pathological podocyturia consisting of podocytes with decreased nephrin mRNA expression persisted even after proteinuria decreased to a level similar to that in NCP women.

Topics: Adult; Case-Control Studies; Female; Humans; Intracellular Signaling Peptides and Proteins; Membrane Proteins; Podocytes; Postpartum Period; Pre-Eclampsia; Pregnancy; Urine; Young Adult

Podocyte depletion in the kidney is associated with end-stage kidney disease (ESKD). Pre-eclampsia (PE) increases the risk of ESKD in later life. This study was performed to determine whether nephrinuria (soluble nephrin in the urine) is correlated with proteinuria and/or podocyturia (podocytes in the urine) in PE women.. Eighty-three urine samples, consisting of 45 and 38 samples from 27 normotensive and nine PE women, respectively, underwent simultaneous determination of nephrin, protein, and creatinine concentrations in the urine supernatant and quantitative analysis of podocyte-specific protein mRNA expression. This included podocin (Pod-mRNA) and nephrin (Nep-mRNA), using real-time polymerase chain reaction in the pelleted urine. Nephrinuria and proteinuria were corrected by creatinine concentration. Pod- and Nep-mRNA expression levels were corrected by GAPDH.. Nephrinuria, proteinuria, Pod-mRNA expression, and Nep-mRNA expression all increased with advancing gestation in PE women, while not in normotensive women. The nephrinuria was strongly correlated with proteinuria (R = 0.901, P <  0.001), Pod-mRNA expression level (R = 0.824, P < 0.001), and Nep-mRNA expression level (R  =  0.724, P <  0.001) in urine samples from PE women, while the nephrinuria was significantly correlated with proteinuria alone (R  =  0.419, P <  0.005) in urine samples from normotensive women.. Nephrinuria reflected well the degrees of proteinuria and podocyturia in PE women. This suggested that increased nephrinuria/proteinuria was associated with podocyte loss in the kidneys of PE women.

Topics: Adult; Creatine; Female; Gestational Age; Humans; Kidney Failure, Chronic; Membrane Proteins; Podocytes; Pre-Eclampsia; Pregnancy; Proteinuria; Risk Factors; Young Adult

Topics: Animals; Disease Models, Animal; Female; Gene Expression Regulation; Humans; Intracellular Signaling Peptides and Proteins; Kidney; Membrane Proteins; NG-Nitroarginine Methyl Ester; Pre-Eclampsia; Pregnancy; Rats; Rats, Sprague-Dawley; RNA, Messenger; Sildenafil Citrate

The aim of this study was to evaluate serum and urinary nephrin levels of normal pregnancy to establish a standard reference value and to compare them with patients who subsequently developed preeclampsia (PE).. In this prospective study, 117 healthy singleton pregnancies were enrolled between 6 to 20 weeks of gestation at 2 participating medical centers during October 2010 to March 2012. Urine and serum samples were collected at the time of enrollment, each trimester, and at 4 to 6 weeks postpartum. Enzyme-linked immunosorbent assay for nephrin was performed and samples from patients who subsequently developed PE were compared to the normal patients.. Of 117 patients initially enrolled, 99 patients delivered at the study centers and of those patients, 12 (12.1%) developed PE at a median gestational age of 34⁺⁴ weeks (range 29⁺⁵-36⁺⁶). In the normal patients (n=68), serum nephrin level decreased and urinary nephrin level increased during the latter of pregnancy. In 12 patients who subsequently developed PE, a significant rise in the 3rd trimester serum and urinary nephrin levels, compared to the controls, was observed (p<0.001), and this increase occurred 9 days prior to the onset of clinical disease.. As the onset of PE was preceded by the rise in the serum and urinary nephrin in comparison to normal pregnancy, serum and urinary nephrin may be a useful predictive marker of PE.

Topics: Adult; Biomarkers; Case-Control Studies; Enzyme-Linked Immunosorbent Assay; Female; Gestational Age; Humans; Membrane Proteins; Pre-Eclampsia; Pregnancy; Pregnancy Proteins; Pregnancy Trimester, Third; Prospective Studies; Reference Standards

Podocyte injury has been suggested to induce phenotypic alteration of glomerular podocytes and accelerate the detachment of podocytes from the glomeruli resulting in podocyturia. However, it is not clear whether podocyte phenotypic alteration occurs in the urine of women with preeclampsia (PE). Seventy-seven and 116 pelleted urine samples from 38 and 18 women at various stages of normal and PE pregnancies, respectively underwent quantitative analysis of podocyte-specific or associated protein mRNA expression, including podocin, nephrin, and synaptopodin using RT-PCR. Significant proteinuria in pregnancy (SPIP) is defined as protein:creatinine ratio (P/Cr, mg/mg) ≥ 0.27 in the urine supernatant. All three urine-pellet mRNAs expression levels were significantly positively correlated with P/Cr levels, suggesting that podocyturia increased with proteinuria. The podocin:nephrin mRNA ratio (PNR) and synaptopodin:nephrin mRNA ratio (SNR) increased significantly with increasing P/Cr, while the podocin:synaptopodin mRNA ratio (PSR) did not change significantly according to P/Cr, resulting in significantly higher PNR and SNR, but not PSR levels, in urine from PE women with than without SPIP. The PNR, SNR, and PSR in urine from PE women before onset of SPIP were comparable to those from controls. Thus, nephrin mRNA expression was reduced in the podocytes recovered from PE women.

Topics: Adult; Cell Adhesion; Female; Gene Expression; Humans; Intracellular Signaling Peptides and Proteins; Membrane Proteins; Microfilament Proteins; Podocytes; Pre-Eclampsia; Pregnancy; Proteinuria; Reverse Transcriptase Polymerase Chain Reaction; Time Factors; Young Adult

To investigate the possibility of nephrinuria as a screening tool for the risk of pre-eclampsia (PE).. Prospective observational study.. A single university hospital. Changes in urinary nephrin:creatinine ratio (NCR, ng/mg) and protein:creatinine ratio (PCR, mg/mg) in pregnancy were determined. Significant proteinuria in pregnancy (SPIP) was defined as PCR>0.27. PE was diagnosed in women with both SPIP and hypertension.. 89 pregnant women in whom neither hypertension nor SPIP was present at enrolment, providing 31, 125 and 93 random urine samples during first, second and third trimesters, respectively.. PE developed in 14 of the 89 women. NCR increased with increasing PCR in 14 women with PE (correlation coefficient, 0.862; p<0.0001). In contrast, NCR did not change significantly despite significant increases in PCR in 75 women with normotensive pregnancies defined as neither SPIP nor hypertension, indicating that there was little increase in nephrinuria over the physiological range of proteinuria in pregnancy. Relative risk of later development of PE among asymptomatic second and third trimester women with NCR (ng/mg) >122 (95th centile value for 75 women with normotensive pregnancies) was 5.93 (95% CI 2.59 to 13.6; 60% (6/10) vs 10% (8/79)) and 13.5 (95% CI 3.31 to 55.0; 75% (6/8) vs 5.5% (2/36)), respectively, compared with women with NCR≤122 at that time.. Nephrinuria was unlikely to increase in normal pregnancy. A certain NCR cut-off may efficiently differentiate women at higher risk of PE.

Topics: Adult; Biomarkers; Creatinine; Feasibility Studies; Female; Humans; Hypertension, Pregnancy-Induced; Membrane Proteins; Parity; Pre-Eclampsia; Pregnancy; Pregnancy Trimesters; Prenatal Diagnosis; Prospective Studies; Proteinuria; Risk Assessment; Young Adult

We investigated the relationship between proteinuria in L-NAME induced preeclampsia and the expression of nephrin and podocin, and the effect of low-molecular-weight-heparin (LMWH) on proteinuria in rats.. We detected nephrin and podocin expression of kidneys of pregnant rats after L-NAME and after LMWH intervening pregnant rats.. Glomerular nephrin expression in L-NAME induced preeclampsia significantly decreased, but not podocin. Nephrin was relatively increased after LMWH intervention and this was accompanied by a decrease in proteinuria.. We demonstrate that down-regulation of nephrin is involved in L-NAME induced proteinuria, and that LMWH reduces proteinuria by up-regulation of neprhin.

Topics: Animals; Disease Models, Animal; Drug Evaluation, Preclinical; Female; Heparin, Low-Molecular-Weight; Intracellular Signaling Peptides and Proteins; Kidney; Male; Membrane Proteins; NG-Nitroarginine Methyl Ester; Pre-Eclampsia; Pregnancy; Proteinuria; Random Allocation; Rats, Wistar

Preeclampsia, a hypertensive multisystem disease that complicates 5-8% of all pregnancy, is a major cause for maternal and fetal mortality and morbidity. The disease is associated with increased spontaneous and evoked preterm birth and remote cardio-renal disorders in the mother and offspring. Thus the ability to predict the disease should lead to earlier care and decreased morbidity. This has led to fervent attempts to identify early predictive biomarkers and research endeavors that have expanded as we learn more regarding possible causes of the disease. As preeclampsia is associated with specific renal pathology including podocyte injury, early urinary podocyte (podocyturia), or the podocyte specific proteinuria nephrin in the urine (nephrinuria), as well as the more easily measured urinary albumin (albuminuria), have all been suggested as predictive markers. We performed a prospective study recruiting 91 pregnant women (78 of whom were high risk) and studied the predictive ability of these three urinary biomarkers. The subjects were recruited between 15-38 weeks of gestation. Fourteen patients, all in the high-risk obstetric group, developed preeclampsia. The levels of podocyturia, nephrinuria, and albuminuria were variably higher in the high-risk pregnant patients who developed preeclampsia. The sensitivities and specificities for podocyturia were 70% and 43%, for albuminuria were 36% and 96%, and for nephrinuria were 57% and 58%, respectively. Also, abnormal nephrinuria (69%) and podocyturia (38%) were detected in low risk women who had uncomplicated gestations; none of these women exhibited albuminuria. In our study, none of the three urinary markers achieved the minimum predictive values required for clinical testing. The lack of excessive albuminuria, however, may indicate a preeclampsia-free gestation. Given a discrepant literature, further studies with larger sample size should be considered.

Topics: Adult; Albuminuria; Biomarkers; Creatinine; Female; Humans; Membrane Proteins; Podocytes; Pre-Eclampsia; Pregnancy; Pregnancy Trimester, Second; Pregnancy Trimester, Third; Prospective Studies; Risk

The underlying mechanisms of proteinuria, a main characteristic of preeclampsia (PE), have not yet been fully elucidated. Evidence indicates that the renin-angiotensin system (RAS) is involved in the pathogenesis of this disease, including decreased angiotensin-(1-7) [Ang-(1-7)] levels in the circulation and urine. In the present study, we examined the damage to podocytes induced by preeclamptic serum and the effects of Ang-(1-7) on podocytes treated with preeclamptic serum, as well as the underlying mechanisms. The podocytes were incubated with serum obtained from women with PE or with serum from women with normal pregnancies for different periods of time. Cell viability was determined by CCK-8 assay. The cells were treated with various concentrations of Ang-(1-7) and A779 [an (Ang-(1-7) antagonist]. The effects of Ang-(1-7) on the expression of podocyte-specific proteins [nephrin, Wilms tumor‑1 (WT-1) and podocin] and the phosphorylation of mitogen-activated protein kinases (MAPKs) were investigated by western blot analysis. Changes in F-actin rearrangement were determined by immunofluorescence. Podocyte apoptosis was determined by flow cytometry. The results revealed that in the cultured podocytes incubated with preeclamptic serum, there was a decrease in the expression of podocyte-specific proteins (nephrin and WT-1 but not podocin), a rearrangement of F-actin and apoptosis compared with the control group. However, treatment with Ang-(1-7) attenuated podocyte injury in the preeclamptic group, which may be mediated through the downregulation of MAPK (p38, ERK1/2 and JNK) phosphorylation. Thus, our data suggest that Ang-(1-7) plays a protective role in PE through the downregulation of MAPK phosphorylation.

Topics: Actins; Adult; Angiotensin I; Angiotensin II; Apoptosis; Cell Survival; Female; Humans; Intracellular Signaling Peptides and Proteins; MAP Kinase Signaling System; Membrane Proteins; Mitogen-Activated Protein Kinases; Peptide Fragments; Phosphorylation; Podocytes; Pre-Eclampsia; Pregnancy; Proto-Oncogene Mas; Proto-Oncogene Proteins; Receptors, G-Protein-Coupled

To compare the levels of urinary excretion of nephrin in women experiencing either normotensive or severe preeclamptic pregnancies, and to examine the relationship between urinary nephrin levels and clinical parameters of preeclampsia.. In a case control study we collected serum and urine specimens from women with normal pregnancy (n=30) and from women with severe preeclampsia (n=43). Serum nephrin levels and urinary nephrin concentrations were measured in all patients.. Both serum and urine concentrations of nephrin were significantly higher in the severe preeclamptic group than in the normal pregnancy group. In addition, we identified a significant relationship between urinary nephrin levels and urine protein concentrations in the severe preeclamptic group. Urine nephrin concentrations were also correlated with serum creatinine levels and with diastolic blood pressure in the severe preeclamptic group.. The positive correlations observed in this study suggest that urinary nephrin excretion might play an important role in the pathogenesis of proteinuria during preeclampsia and could be a good indicator of renal damage.

Topics: Adult; Biomarkers; Case-Control Studies; Female; Humans; Membrane Proteins; Pre-Eclampsia; Pregnancy; Vascular Endothelial Growth Factor Receptor-1

Emerging evidence has shown that podocyte injury and reduced specific podocyte protein expressions contribute to proteinuria in preeclampsia. We collected urine specimens from women with preeclampsia to study whether podocyte-specific protein shedding is associated with renal barrier dysfunction. Urine specimens from women with normal pregnancies and from pregnant women complicated by chronic hypertension were used for comparison. We determined soluble podocyte slit protein nephrin levels in the urine specimens. Podocalyxin, βig-h3, and VEGF concentrations were also measured. We found that nephrin and podocalyxin were barely detectable in the urine specimens from normal pregnant women and from women with chronic hypertension. In preeclampsia, urinary nephrin and podocalyxin concentrations were significantly increased and highly correlated to each other, r(2) = 0.595. Nephrin and podocalyxin were also correlated with urine protein concentrations. βig-h3 was detected in the urine specimens from women with preeclampsia, and it is highly correlated with nephrin and podocalyxin concentrations in preeclampsia. βig-h3 was undetectable in normal pregnancy and pregnancy complicated by chronic hypertension. Elevated VEGF levels were also found in women with preeclampsia compared with those of normal pregnancy and pregnancy complicated by chronic hypertension. These results provide strong evidence that podocyte protein shedding occurs in preeclampsia, and their levels are associated with proteinuria. The finding of urinary βig-h3 excretion in preeclampsia suggests that increased transforming growth factor activity might also be involved in the kidney lesion in this pregnancy disorder.

Topics: Adult; Biomarkers; Case-Control Studies; Extracellular Matrix Proteins; Female; Humans; Hypertension; Kidney; Membrane Proteins; Pre-Eclampsia; Pregnancy; Pregnancy Complications, Cardiovascular; Sialoglycoproteins; Signal Transduction; Transforming Growth Factor beta; Vascular Endothelial Growth Factor A

Preeclampsia is a significant cause of maternal and fetal morbidity and mortality worldwide. A clinically useful screening test that can predict development of preeclampsia at an early stage is urgently needed. The detection of podocyturia by immunohistochemistry after cell culture has been noted as a reliable marker for preeclampsia. However, this method is laborious and carries the risk of cell culture contamination. The aim of this study was to investigate the diagnostic value of quantitative polymerase chain reaction as a rapid method to detect preeclampsia. Clean-catch urine samples were collected from preeclamptic (n=35), healthy pregnant (n=34), and healthy nonpregnant (n=12) women. Furthermore, a control group of women with gestational hypertension (n=5) was included. Quantitative polymerase chain reaction analysis was performed for podocyte-specific markers. Receiver operating characteristic curve analyses were performed. Significantly elevated mRNA levels of nephrin, podocin, and vascular endothelial growth factor were detected in preeclamptic women compared with healthy pregnant and healthy nonpregnant controls. In addition, significantly elevated levels of nephrin mRNA were detected in urine of preeclamptic women compared with women with gestational hypertension. A positive correlation (ρ=0.82; P<0.0001) was observed between nephrin and vascular endothelial growth factor mRNA levels in preeclamptic women. Receiver operating characteristic curve analyses demonstrated a strong ability of this method to discriminate between the different study groups. Quantitative polymerase chain reaction analysis of podocyte-specific molecules in urine samples is a rapid and reliable method to quantify podocyturia. We demonstrate that this method distinguishes preeclamptic patients from healthy controls and women with gestational hypertension. This method may be a tool for the detection of preeclampsia at an earlier stage, thereby preventing maternal and fetal morbidity and mortality.

Topics: Adult; Case-Control Studies; Female; Humans; Hypertension, Pregnancy-Induced; Membrane Proteins; Podocytes; Pre-Eclampsia; Predictive Value of Tests; Pregnancy; Real-Time Polymerase Chain Reaction; Sensitivity and Specificity; Vascular Endothelial Growth Factor A

The objective of this study was to examine whether nephrin is present in the urine of patients with severe preeclampsia.. A total of 45 women were recruited for this study, and 25 of these patients had severe preeclampsia. Twenty gestational age-matched normotensive women without proteinuria served as a control group. Urine samples were collected close to delivery, typically ≤24 h before delivery. Western blot analysis was performed to assess the excretion of nephrin in urine.. Nephrin was detected in all urine samples from all the women with severe preeclampsia but not in urine from normotensive controls.. In pregnancy complicated by severe preeclampsia, urinary nephrin shedding, reflecting the damage in the glomerular slit diaphragm, was observed.

Topics: Adult; Case-Control Studies; Female; Humans; Membrane Proteins; Pre-Eclampsia; Pregnancy; Prenatal Diagnosis; Severity of Illness Index

This study was undertaken to test the hypothesis that altered podocyte slit protein nephrin distribution is associated with disturbed polarity protein expressions in podocytes from preeclampsia (PE). We examined expressions and distributions of nephrin, podoplanin, polarity protein partitioning defective-3 (PARD-3), and PARD-6 in podocytes from PE. Podocyte cell line (AB 8/13 cells) was used as control. Podocytes were found in all severe PE cases. In contrast, no podocyte was found in the samples from normal pregnancies and mild PE. Compared to control cells, nephrin, PARD-3 and PARD-6 expressions were reduced or lost in podocytes from severe PE. Podoplanin was expressed in podocyte surface membrane on control cells but reduced in podocytes from PE. These findings indicate that loss of slit protein nephrin and polarity protein PARD-3 and PARD-6 on foot processes could explain for podocyte detachment from glomerular basement membrane and lead to podocyte shedding in PE.

Topics: Adaptor Proteins, Signal Transducing; Blotting, Western; Cell Cycle Proteins; Female; Humans; Membrane Glycoproteins; Membrane Proteins; Microscopy, Phase-Contrast; Podocytes; Pre-Eclampsia; Pregnancy

Renal injury is a common pathophysiological feature in women with preeclampsia as evidenced by increased protein leakage (proteinuria) and glomerular injury (glomerular endotheliosis). Recently, podocyturia was found in preeclampsia, suggesting podocyte shedding occurs in this pregnancy disorder. However, podocyte function in preeclampsia is poorly understood. In this study, the authors have examined podocyte-specific protein expressions for nephrin, glomerular epithelial protein 1 (GLEPP-1), and ezrin in kidney biopsy tissue sections from women with preeclampsia. Expressions for vascular endothelial growth factor (VEGF) and its receptor Flt-1 and oxidative stress marker nitrotyrosine and antioxidant CuZn-superoxide dismutase (CuZn-SOD) were also examined. Kidney tissue sections from nonhypertensive and chronic hypertensive participants were stained as controls. The findings were (1) nephrin and GLEPP-1 were mainly expressed in glomerular podocytes; (2) ezrin was expressed in both glomerular podocytes and tubular epithelial cells; (3) compared to tissue sections from nonhypertensive and chronic hypertensive participants, nephrin and GLEPP-1 expressions were much reduced in tissue sections from preeclampsia and ezrin expression was reduced in podocytes; (4) enhanced VEGF, Flt-1, and nitrotyrosine, but reduced CuZn-SOD, expressions were observed in both glomerular podocytes and endothelial cells in tissue sections from preeclampsia; and (5) the expression pattern for nephrin, GLEPP-1, ezrin, VEGF, Flt-1, and CuZn-SOD were similar between tissue sections from nonhypertensive and chronic hypertensive participants. Although the authors could not conclude from this biopsy study whether the podocyte injury is the cause or effect of the preeclampsia phenotype, the data provide compelling evidence that podocyte injury accompanied by altered angiogenesis process and increased oxidative stress occurs in kidney of patients with preeclampsia.

Topics: Adult; Female; Gene Expression; Humans; Kidney; Membrane Proteins; Podocytes; Pre-Eclampsia; Pregnancy; Receptor-Like Protein Tyrosine Phosphatases, Class 3; Retrospective Studies; Tyrosine; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factor Receptor-1

In preeclampsia (PE), proteinuria has been associated with a reduced expression of nephrin by podocytes. In the present study, we investigated in vitro on human cultured podocytes the mechanism responsible for nephrin loss in PE. Sera from patients with PE did not directly downregulate the expression of nephrin. In contrast, conditioned medium obtained from glomerular endothelial cells incubated with PE sera induced loss of nephrin and synaptopodin, but not of podocin, from podocytes. Nephrin loss was related to a rapid shedding of the protein from the cell surface due to cleavage of its extracellular domain by proteases and to cytoskeleton redistribution. The absence of nephrin mRNA downregulation together with nephrin reexpression within 24 h confirm that the loss of nephrin was not related to a reduced synthesis. Studies with an endothelin-1 (ET-1) receptor antagonist that abrogated the loss of nephrin triggered by glomerular endothelial conditioned medium of PE sera indicated that ET-1 was the main effector of nephrin loss. Indeed, ET-1 was synthesized and released from glomerular endothelial cells when incubated with PE sera, and recombinant ET-1 triggered nephrin shedding from podocytes. Moreover, VEGF blockade induced ET-1 release from endothelial cells, and in turn the conditioned medium obtained triggered nephrin loss. In conclusion, the present study identifies a potential mechanism of nephrin loss in PE that may link endothelial injury with enhanced glomerular permeability.

Topics: Animals; Blotting, Western; Cell Line; Endothelial Cells; Endothelin-1; Enzyme-Linked Immunosorbent Assay; Extracellular Matrix; Female; Flow Cytometry; Fluorescent Antibody Technique; Guinea Pigs; Humans; Immunoprecipitation; Intracellular Signaling Peptides and Proteins; Kidney Glomerulus; Membrane Proteins; Podocytes; Pre-Eclampsia; Pregnancy; Reverse Transcriptase Polymerase Chain Reaction; Serum

Topics: Biopsy; Endothelium; Female; Humans; Kidney Glomerulus; Membrane Proteins; Podocytes; Pre-Eclampsia; Pregnancy; Proteinuria; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factor Receptor-1

Preeclampsia is a pregnancy-specific disorder characterized by hypertension and proteinuria. In other disease states, proteinuria has been linked to altered expressions of podocyte foot-process proteins, but this has not been studied in women with preeclampsia. We sought to test the hypothesis that proteinuria in preeclampsia is associated with dysregulated expression of the podocyte cytoskeleton and/or tight junction proteins.. Renal tissue was obtained from autopsy material from seven women who had severe preeclampsia during the second half of their pregnancies up to 48 h after delivery, and who subsequently died. As controls, we used autopsy material from two women who died accidentally during the second half of their otherwise normal pregnancies. Immunohistochemical stains for nephrin, synaptopodin and podocin were performed on representative sections prepared from paraffin-embedded material.. Expression of both nephrin and synaptopodin was markedly decreased in preeclamptic compared with control kidney sections. By contrast, both cases and controls demonstrated strong staining for podocin.. We conclude that down-regulation of nephrin and synaptopodin is associated with proteinuria in women with preeclampsia. Recent studies have demonstrated that soluble vascular endothelial growth factor receptor 1 (sFlt-1) levels are elevated in preeclampsia compared with normal pregnancy. Studies in mice have shown that sFlt-1 may play a role in inducing proteinuria by neutralizing vascular endothelial growth factor (VEGF) and suppressing nephrin. Proteinuria and elevations of sFlt-1 in preeclampsia are temporally related, further supporting a possible role of sFlt-1 in the dysregulation of podocyte foot-process proteins.

Topics: Adolescent; Adult; Animals; Antibodies; Biopsy; Case-Control Studies; Disease Models, Animal; Female; Gene Expression Regulation; Humans; Intracellular Signaling Peptides and Proteins; Kidney Glomerulus; Membrane Proteins; Mice; Mice, Inbred Strains; Microfilament Proteins; Pre-Eclampsia; Pregnancy; Proteinuria; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factor Receptor-1