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Nikolov AG, Popovski NK, Blazheva S. Levels of serum podocalyxin in preeclampsia and relationship with maternal echocardiographic and Doppler ultrasound parameters. Folia Med (Plovdiv) 2022; 64:913-921. [PMID: 36876570 DOI: 10.3897/folmed.64.e70074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2021] [Accepted: 09/20/2021] [Indexed: 01/01/2023] Open
Abstract
INTRODUCTION Podocalyxin (PCX) is an indicator of glomerular injury. Aside from the kidney, it is expressed in the endothelial cells of various organs. Echographic examinations are useful in assessing the alterations in cardiovascular structure and function during pregnancy.
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Affiliation(s)
| | - Nikola K Popovski
- Clinic of Obstetrics and Gynecology, University Hospital, Pleven, Bulgaria
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2
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Karatoy Erdem B, Özcan M, Yılmaz VT, Akkaya B, Çetinkaya R, Ersoy F, Süleymanlar G, Akbas H. A UFLC-MS/MS Method for the Simultaneous Analysis of Urinary Podocin and Podocalyxin in Patients with Nephrotic Syndrome. Lab Med 2021; 53:246-254. [PMID: 34698337 DOI: 10.1093/labmed/lmab089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
OBJECTIVE To create an efficient and robust mass spectrometric method for the simultaneous quantitation of podocin and podocalyxin in urine samples and to evaluate urinary podocin and podocalyxin levels in patients with nephrotic syndrome (NS). METHODS A mass spectrometric method was generated for the measurement of tryptic peptides in urine sediment. Separation of peptides was achieved via liquid chromatography, and mass spectrometric analyses were conducted by electrospray ionization triple-quadrupole mass spectrometry in the multiple reaction monitoring mode. RESULTS Intra- and interassay precision values were below 12% and accuracies ranged from 87% to 111% for both of peptides. The validated method was successfully applied to detect these peptides in patients with NS. Urine podocin and podocalyxin levels were significantly higher in patients with NS compared to healthy controls. CONCLUSIONS This proposed mass spectrometric method provides technological evidence that will benefit the clinical field in the early diagnosis and follow-up of NS.
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Affiliation(s)
- Bilge Karatoy Erdem
- Akdeniz University Faculty of Medicine Department of Clinical Biochemistry, Antalya, Turkey
| | - Mualla Özcan
- Akdeniz University Faculty of Medicine Department of Pathology, Antalya, Turkey
| | - Vural Taner Yılmaz
- Akdeniz University Faculty of Medicine Department of Nephrology, Antalya, Turkey
| | - Bahar Akkaya
- Akdeniz University Faculty of Medicine Department of Pathology, Antalya, Turkey
| | - Ramazan Çetinkaya
- Akdeniz University Faculty of Medicine Department of Nephrology, Antalya, Turkey
| | - Fevzi Ersoy
- Akdeniz University Faculty of Medicine Department of Nephrology, Antalya, Turkey
| | - Gültekin Süleymanlar
- Akdeniz University Faculty of Medicine Department of Nephrology, Antalya, Turkey
| | - Halide Akbas
- Akdeniz University Faculty of Medicine Department of Clinical Biochemistry, Antalya, Turkey
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Siwińska N, Pasławska U, Bąchor R, Szczepankiewicz B, Żak A, Grocholska P, Szewczuk Z. Evaluation of podocin in urine in horses using qualitative and quantitative methods. PLoS One 2020; 15:e0240586. [PMID: 33057359 PMCID: PMC7561189 DOI: 10.1371/journal.pone.0240586] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2019] [Accepted: 09/29/2020] [Indexed: 11/26/2022] Open
Abstract
No sensitive method for diagnosing early kidney dysfunction in horses has been identified so far. Many studies carried out in humans and small animals show that podocin can be useful to diagnose various kidney diseases, mainly affecting the glomeruli. The aim of this study was to perform a qualitative and quantitative analysis of podocin in urine samples obtained from healthy horses, horses with clinical kidney dysfunction and horses at risk of acute kidney injury. The study objectives aimed to assess: (1) whether the selected podocin tryptic peptide for LC-MS-MRM allows for podocin detection in horse; and (2) whether the species-specific ELISA test makes this detection possible as well;, (3) whether the chosen methods are sensitive enough to detect kidney dysfunction and glomerular injury, (4) whether the results of the tests applying both methods correspond with one another, (5) whether the results correlate with the hematological and biochemical data. The signals that may indicate the presence of trypsin fragments of podocin were found in three healthy horses, all the horses diagnosed with kidney dysfunction and half of the animals at risk for acute kidney injury. The concentration of podocin, diagnosed with the ELISA test was as follows: from 0.19 to 1.2 ng/ml in healthy animals, from 0.19 to 20.0 ng/ml in AKI horses, from 0.29 to 5.71 ng/ml in horses at risk for acute kidney injury. The results of both methods corresponded significantly. Podocin may be a potential biomarker of clinical kidney disease in horses and may be used in the detection of glomerular injury. However, its use is limited by the possibility of physiological podocyturia. LC-MS-MRM seems to be a more sensitive method to evaluate the presence of podocin than the ELISA test, whilst selected tryptic peptides of podocin appear to apply to horses. The ELISA test showed greater effectiveness in excluding the disease than in confirming it.
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Affiliation(s)
- Natalia Siwińska
- Department of Internal Diseases with Clinic for Horses, Dogs and Cats, Faculty of Veterinary Medicine, Wrocław University of Environmental and Life Sciences, Wrocław, Poland
| | - Urszula Pasławska
- Department of Internal Diseases with Clinic for Horses, Dogs and Cats, Faculty of Veterinary Medicine, Wrocław University of Environmental and Life Sciences, Wrocław, Poland
- Veterinary Institute, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University, Toruń, Poland
| | | | - Barbara Szczepankiewicz
- Department of Internal Diseases with Clinic for Horses, Dogs and Cats, Faculty of Veterinary Medicine, Wrocław University of Environmental and Life Sciences, Wrocław, Poland
| | - Agnieszka Żak
- Department of Internal Diseases with Clinic for Horses, Dogs and Cats, Faculty of Veterinary Medicine, Wrocław University of Environmental and Life Sciences, Wrocław, Poland
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Ameliorative Effects of Bredemolic Acid on Markers Associated with Renal Dysfunction in a Diet-Induced Prediabetic Rat Model. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2020; 2020:2978340. [PMID: 32655765 PMCID: PMC7327579 DOI: 10.1155/2020/2978340] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Accepted: 03/31/2020] [Indexed: 01/13/2023]
Abstract
Recently, studies have shown that renal dysfunction is associated not only with overt diabetes but also with the preceding stage known as prediabetes. Diet and pharmacological interventions are the therapeutic approaches to managing prediabetes, but the compliance in combining the two interventions is low. Hence, the efficacy of pharmacological intervention is reduced without diet modification. In our previous study, we established that bredemolic acid (BA) ameliorated glucose homeostasis via increased GLUT 4 expression in the skeletal muscle of prediabetic rats in the absence of diet intervention. However, the effects of bredemolic acid on renal function in prediabetic condition are unknown. Therefore, this study was aimed at investigating the ameliorative effects of bredemolic acid on renal dysfunction in a diet-induced prediabetic rat model. Thirty-six Sprague-Dawley male rats (150-180 g) were divided into two groups: the nonprediabetic (n = 6) and prediabetic (n = 30) groups which were fed normal diet (ND) and high-fat high-carbohydrate (HFHC) diet, respectively, for 20 weeks. After the 20th week, the prediabetic groups were subdivided into prediabetic control (PD) and 4 other prediabetic groups which were treated with either BA (80 mg/kg) or metformin (MET, 500 mg/kg) for further 12 weeks (21st to 32nd). Plasma, urine, and kidney samples were collected for biochemical analysis. The untreated prediabetic (PD) rats presented increased fluid intake and urine output; increased creatinine, urea, and uric acid plasma concentrations; albuminuria; proteinuria; sodium retention; potassium loss; increased aldosterone and kidney injury molecule (KIM-1) concentration; and increased urinary podocin mRNA expression. However, BA administration attenuated the renal markers and oxidative stress and decreased the urinary podocin mRNA expression. In conclusion, BA administration, regardless of diet modification, attenuates renal dysfunction in an experimentally induced prediabetic state.
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Early Detection of Active Glomerular Lesions in Dogs and Cats Using Podocin. J Vet Res 2019; 63:573-577. [PMID: 31934669 PMCID: PMC6950428 DOI: 10.2478/jvetres-2019-0062] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Accepted: 11/05/2019] [Indexed: 12/04/2022] Open
Abstract
In veterinary medicine, sensitive and specific markers of the early stages of renal failure still remain to be established. Podocytes could be a promising diagnostic tool in veterinary nephrology, especially in the differentiation of active pathological disease and glomerulopathies. Podocin is one of the robust proteins exploitable in detection of podocyturia. This article presents podocyte detection in urine for diagnostic purposes in veterinary medicine using a variety of methods. We describe the advantages and disadvantages of the immunohistochemical technique currently used, and of scanning microscopy, chromatography, and immunostaining. The identification of podocin-positive cells is a promising diagnostic tool in the detection of the early stages of glomerular basement membrane damage. The detection of renal failure prior to the occurrence of azotaemia is of high clinical importance from the clinical and scientific points of view.
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Fayed A, Rahman Tohamy IA, Kahla H, Elsayed NM, El Ansary M, Saadi G. Urinary podocyte-associated mRNA profile in Egyptian patients with diabetic nephropathy. Diabetes Metab Syndr 2019; 13:2849-2854. [PMID: 31425946 DOI: 10.1016/j.dsx.2019.07.048] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Accepted: 07/29/2019] [Indexed: 11/28/2022]
Abstract
INTRODUCTION Podocyte injury and subsequent excretion in urine play a crucial role in the pathogenesis and progression of diabetic nephropathy (DN). Quantification of messenger RNA expression in urinary sediment by real-time PCR is emerging as a noninvasive method of screening DN-associated biomarkers. We aimed to study the expression of podocyte-associated genes in urinary sediment and their relation to disease severity in type 2 diabetic Egyptian patients with diabetic nephropathy. METHOD ology: Sixty patients with type 2 diabetes mellitus were recruited in addition to twenty non diabetic healthy volunteers. Relative mRNA abundance of nephrin, podocalyxin, and podocin were quantified, and correlations between target mRNAs and clinical parameters were examined. RESULTS The urinary mRNA levels of all genes studied were significantly higher in diabetics compared with controls (p < 0.001), and mRNA levels increased with DN progression. Urinary mRNA levels of all target genes positively correlated with both UAE and HbA1c. The expression of nephrin, podocalyxin, and podocin mRNA correlated with serum creatinine {(r = 0.397, p value = 0.002), (r = 0.431, p value = 0.001), (r = 0.433, p value = 0.001) respectively}. CONCLUSION The urinary mRNA profiles of nephrin, podocalyxin, and podocin were found to increase with the progression of DN, which suggested that quantification of podocyte-associated molecules will be useful biomarkers of DN.
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Affiliation(s)
- Ahmed Fayed
- Nephrology unit, Internal Medicine Department, School of Medicine, Cairo University, Egypt.
| | | | - Hala Kahla
- Endocrinology unit, Internal Medicine Department, School of Medicine, Cairo University, Egypt
| | - Naglaa M Elsayed
- Endocrinology unit, Internal Medicine Department, School of Medicine, Cairo University, Egypt
| | - Mervat El Ansary
- Clinical Pathology Department, School of Medicine, Cairo University, Egypt
| | - Gamal Saadi
- Nephrology unit, Internal Medicine Department, School of Medicine, Cairo University, Egypt
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Szczepankiewicz B, Bąchor R, Pasławski R, Siwińska N, Pasławska U, Konieczny A, Szewczuk Z. Evaluation of Tryptic Podocin Peptide in Urine Sediment Using LC-MS-MRM Method as a Potential Biomarker of Glomerular Injury in Dogs with Clinical Signs of Renal and Cardiac Disorders. Molecules 2019; 24:molecules24173088. [PMID: 31454880 PMCID: PMC6749423 DOI: 10.3390/molecules24173088] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2019] [Revised: 08/19/2019] [Accepted: 08/23/2019] [Indexed: 01/31/2023] Open
Abstract
The early asymptomatic stage of glomerular injury is a diagnostic challenge in the course of renal and extra-renal disease, e.g., heart insufficiency. It was found that podocin, a podocyte-specific protein present in the urine, may serve as a biomarker in the diagnosis of glomerular disease in humans and animals including glomerulonephritis, glomerulosclerosis, amyloidosis, or nephropathy. Therefore, there is a need of development of the sensitive and straightforward method of urinary podocin identification. In this work, we report our extended research under the glomerular injury investigation in dogs by application of clinical examination and LC-MS-MRM method in the identification of canine podocin in urine samples. The LC-MS-MRM method is based on the identification of podocin tryptic peptide with the 218H-AAEILAATPAAVQLR-OH232 sequence. The model peptide was characterized by the highest ionization efficiency of all the proposed model podocin tryptic peptides in a canine urine sediment according to the LC-MS/MS analysis. The obtained results revealed the presence of the model peptide in 40.9% of dogs with MMVD (active glomerular injury secondary to heart disease = cardiorenal syndrome-CRS) and 33.3% dogs with chronic kidney disease. The potential applicability of the developed methodology in the analysis of podocin in canine urine sediments was confirmed.
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Affiliation(s)
- Barbara Szczepankiewicz
- Department of Internal Diseases with Clinic for Horses, Dogs and Cats, Faculty of Veterinary Medicine, Wroclaw University of Environmental and Life Sciences, Pl. Grunwaldzki 47, 50-366 Wrocław, Poland.
| | - Remigiusz Bąchor
- Faculty of Chemistry, University of Wroclaw, F. Joliot-Curie 14, 50-383 Wroclaw, Poland.
| | - Robert Pasławski
- Veterinary Centre Nicolaus Copernicus University Toruń, Gagarina 7, 87-100 Toruń, Poland
| | - Natalia Siwińska
- Department of Internal Diseases with Clinic for Horses, Dogs and Cats, Faculty of Veterinary Medicine, Wroclaw University of Environmental and Life Sciences, Pl. Grunwaldzki 47, 50-366 Wrocław, Poland
| | - Urszula Pasławska
- Department of Internal Diseases with Clinic for Horses, Dogs and Cats, Faculty of Veterinary Medicine, Wroclaw University of Environmental and Life Sciences, Pl. Grunwaldzki 47, 50-366 Wrocław, Poland
- Veterinary Centre Nicolaus Copernicus University Toruń, Gagarina 7, 87-100 Toruń, Poland
| | - Andrzej Konieczny
- Department of Nephrology and Transplantation Medicine, Wroclaw Medical University, Borowska 213, 50-556 Wroclaw, Poland
| | - Zbigniew Szewczuk
- Faculty of Chemistry, University of Wroclaw, F. Joliot-Curie 14, 50-383 Wroclaw, Poland
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Evaluation of the urinary podocalyxin and nephrin excretion levels to determine a safe time interval between two sessions of SWL for renal stones: a non randomized exploratory study. Int Urol Nephrol 2019; 51:1727-1734. [PMID: 31321677 DOI: 10.1007/s11255-019-02229-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2019] [Accepted: 07/05/2019] [Indexed: 10/26/2022]
Abstract
OBJECTIVES We aimed to evaluate the role of nephrin and podocalyxin in determining the intervals between shock wave lithotripsy (SWL) sessions and how soon the kidney damage was recovered. METHODS This work was a prospective study that included 30 patients with unilateral kidney stones. The patients' midflow urine samples were collected before SWL and 1 h, 1 day and 1 week after the procedure. Nephrin and podocalyxin levels in the urine samples were measured by the enzyme-linked immunosorbent assay method. RESULTS Among the 30 patients who underwent SWL, 19 were males and 11 were females. The mean age of the SWL group was 34.7 ± 13.2. Both biomarkers did not correlate with age, creatinine values, body mass index, stone side, stone size, energy, frequency and shock numbers. Nephrin and podocalyxin levels were significantly higher at the pre-SWL point (p < 0.05). After the procedure, a significant decrease was observed in both biomarker levels (p < 0.05). At the end of first day, these levels started to increase progressively up to the end of the first week (p > 0.05). CONCLUSIONS Nephrin and podocalyxin may help to determine early period kidney damage associated with SWL. Post-SWL podocalyxin and nephrin values may be used to determine the interval between SWL sessions.
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Hayashi T, Tokuriki S, Okuno T, Ohta G, Igarashi A, Ohshima Y. Urinary podocalyxin as a possible novel marker of intrauterine nephrogenesis and extrauterine podocyte injury. Pediatr Nephrol 2017; 32:1891-1896. [PMID: 28439668 DOI: 10.1007/s00467-017-3676-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Revised: 03/29/2017] [Accepted: 04/05/2017] [Indexed: 12/17/2022]
Abstract
BACKGROUND The number of nephrons at birth is determined during fetal development and is modulated thereafter by postnatal podocyte injury. Hyperfiltration, caused by a reduced number of nephrons, is a risk factor for chronic kidney disease. It is therefore important to monitor the formation of nephrons. METHODS Urine samples were collected from infants within 1-2 days of birth, with follow-up sampling for preterm infants at 37-39 weeks of corrected age. Urinary levels of podocalyxin (PCX), β2-microglobulin (β2MG), N-acetyl-ß-D-glucosaminidase (NAG), total protein (TP), microalbumin (mAlb) and creatinine were measured and the relationship between these markers evaluated. RESULTS Seventy-nine neonates were enrolled in this study. Urinary levels of PCX at birth were higher than normal adult reference values, with levels increasing up to a gestational age of 36 weeks (p = 0.0242). At 37-39 weeks corrected age, urinary levels of PCX decreased to adult levels. The levels of PCX in the urine at birth were not correlated to urinary levels of β2MG, NAG, TP and mAlb. CONCLUSIONS An increased urinary level of PCX may be a marker of both active nephron formation and podocyte injury sustained at birth. As such, changes in urinary levels of PCX are likely to reflect adaptation of renal function to the extra-uterine environment.
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Affiliation(s)
- Taihei Hayashi
- Department of Pediatrics, Faculty of Medical Sciences, University of Fukui, 23-3 Simoaizuki, Matsuoka, Eiheiji-cho, Yoshida-gun, Fukui, 9101193, Japan.
| | - Shuko Tokuriki
- Department of Pediatrics, Faculty of Medical Sciences, University of Fukui, 23-3 Simoaizuki, Matsuoka, Eiheiji-cho, Yoshida-gun, Fukui, 9101193, Japan
| | - Takashi Okuno
- Department of Pediatrics, Faculty of Medical Sciences, University of Fukui, 23-3 Simoaizuki, Matsuoka, Eiheiji-cho, Yoshida-gun, Fukui, 9101193, Japan
| | - Genrei Ohta
- Department of Pediatrics, Faculty of Medical Sciences, University of Fukui, 23-3 Simoaizuki, Matsuoka, Eiheiji-cho, Yoshida-gun, Fukui, 9101193, Japan
| | - Aiko Igarashi
- Department of Pediatrics, Faculty of Medical Sciences, University of Fukui, 23-3 Simoaizuki, Matsuoka, Eiheiji-cho, Yoshida-gun, Fukui, 9101193, Japan
| | - Yusei Ohshima
- Department of Pediatrics, Faculty of Medical Sciences, University of Fukui, 23-3 Simoaizuki, Matsuoka, Eiheiji-cho, Yoshida-gun, Fukui, 9101193, Japan
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Ivanova EA, Arcolino FO, Elmonem MA, Rastaldi MP, Giardino L, Cornelissen EM, van den Heuvel LP, Levtchenko EN. Cystinosin deficiency causes podocyte damage and loss associated with increased cell motility. Kidney Int 2016; 89:1037-1048. [PMID: 27083281 DOI: 10.1016/j.kint.2016.01.013] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Revised: 12/22/2015] [Accepted: 01/07/2016] [Indexed: 12/14/2022]
Abstract
The involvement of the glomerulus in the pathogenesis of cystinosis, caused by loss-of-function mutations in cystinosin (CTNS, 17p13), is a matter of controversy. Although patients with cystinosis demonstrate glomerular lesions and high-molecular-weight proteinuria starting from an early age, a mouse model of cystinosis develops only signs of proximal tubular dysfunction. Here we studied podocyte damage in patients with cystinosis by analyzing urinary podocyte excretion and by in vitro studies of podocytes deficient in cystinosin. Urine from patients with cystinosis presented a significantly higher amount of podocytes compared with controls. In culture, cystinotic podocytes accumulated cystine compatible with cystinosin deficiency. The expression of podocyte specific genes CD2AP, podocalyxin, and synaptopodin and of the WT1 protein was evident in all cell lines. Conditionally immortalized podocyte lines of 2 patients with different CTNS mutations had altered cytoskeleton, impaired cell adhesion sites, and increased individual cell motility. Moreover, these cells showed enhanced phosphorylation of both Akt1 and Akt2 (isoforms of protein kinase B). Inhibition of Akt by a specific inhibitor (Akti inhibitor 1/2) resulted in normalization of the hypermotile phenotype. Thus, our study extends the list of genetic disorders causing podocyte damage and provides the evidence of altered cell signaling cascades resulting in impaired cell adhesion and enhanced cell motility in cystinosis.
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Affiliation(s)
- Ekaterina A Ivanova
- Department of Development and Regeneration, Laboratory of Pediatric Nephrology, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Fanny O Arcolino
- Department of Development and Regeneration, Laboratory of Pediatric Nephrology, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Mohamed A Elmonem
- Department of Development and Regeneration, Laboratory of Pediatric Nephrology, Katholieke Universiteit Leuven, Leuven, Belgium; Department of Clinical and Chemical Pathology, Faculty of Medicine, Cairo University, Cairo, Egypt
| | - Maria P Rastaldi
- Renal Research Laboratory, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico and Fondazione D'Amico, Milano, Italy
| | - Laura Giardino
- Renal Research Laboratory, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico and Fondazione D'Amico, Milano, Italy
| | - Elisabeth M Cornelissen
- Department of Pediatric Nephrology, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Lambertus P van den Heuvel
- Department of Development and Regeneration, Laboratory of Pediatric Nephrology, Katholieke Universiteit Leuven, Leuven, Belgium; Department of Pediatric Nephrology, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Elena N Levtchenko
- Department of Development and Regeneration, Laboratory of Pediatric Nephrology, Katholieke Universiteit Leuven, Leuven, Belgium.
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Chebotareva NV, Bobkova IN, Neprintseva NV, Kozlovskaya LV, Malkandueva ZT. [Urinary biomarkers for podocyte injury: Significance for evaluating the course and prognosis of chronic glomerulonephritis]. TERAPEVT ARKH 2015; 87:34-39. [PMID: 26281193 DOI: 10.17116/terarkh201587634-39] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
AIM To estimate the degree of podocyte injury in patients with different types of chronic glomerulonephritis (CGN) from the urinary level of podocyte markers and to determine the significance of these indicators as criteria for disease activity and prognosis. SUBJECTS AND METHODS Seventy-three patients with CGN, including 20 with inactive nephritis (Group 1), 23 with obvious urological syndrome (Group 2), 30 with nephrotic syndrome (NS) (Group 3), among them there were 7 patients with severe NS and 7 with NS concurrent with acute nephritic syndrome, were examined. A control group consisted of 8 healthy individuals. In the examined groups, the degree of podocyturia (PCU) was investigated by flow cytometry using podocalyxin-labeled antibodies and the levels of nephrinuria (NU), heat shock protein 27 (HSP27) in urine, interleukin 6 (IL-6), caspase 9, and vascular endothelial growth factor (VEGF) were estimated by ELISA. RESULTS The patients with active CGN were found to have a high level of markers for podocyte injury: PCU and NU, which correlate with the magnitude of proteinuria, severity of NS, and degree of podocytopenia. Those with the severest NS, that concurrent with renal dysfunction in particular, were observed to have a progressive imbalance of inflammatory (IL-6), apoptotic (caspase-9), and defensive (HSP27 and VEGF) factors, which displays the incompetence of self-defense mechanisms in podocytes and contributes to the torpid course of CGN. Progressive PCU and NU are a poor prognostic sign indicating the risk of glomerulonephritis. CONCLUSION The indicators considered are universal for all patients with CGN running with proteinuria and may be used to monitor the course of the disease; moreover, the damaging factors should be considered in conjunction with the defensive factors.
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Affiliation(s)
- N V Chebotareva
- I.M. Sechenov First Moscow State Medical University, Ministry of Health of Russia, Moscow, Russia
| | - I N Bobkova
- I.M. Sechenov First Moscow State Medical University, Ministry of Health of Russia, Moscow, Russia
| | - N V Neprintseva
- I.M. Sechenov First Moscow State Medical University, Ministry of Health of Russia, Moscow, Russia
| | - L V Kozlovskaya
- I.M. Sechenov First Moscow State Medical University, Ministry of Health of Russia, Moscow, Russia
| | - Z T Malkandueva
- I.M. Sechenov First Moscow State Medical University, Ministry of Health of Russia, Moscow, Russia
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Abstract
OBJECTIVES Nephrin is an integral part of podocytes that together with endothelial cells and the basement form the glomerular filtration barrier. Placental ischemia triggers a cascade of events that ultimately result in endothelial malfunction, hypertension, podocytopathy and fetal compromise. METHODS We review the literature to determine if urine nephrin measurements could serve as a useful biomarker to detect early podocyte injury in pre-eclampsia. RESULTS Our search identifies eight studies published to date. The findings of these studies demonstrate that urine nephrin excretion plays a critical role in the pathogenesis of proteinuria during pre-eclampsia and that this is a good indicator of glomerular injury. CONCLUSION There is thus an urgent need for a large multi-centre clinical study using standardized recruitment criteria to determine the full potential of this biomarker in clinical practice.
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Affiliation(s)
- Yogavijayan Kandasamy
- a Department of Neonatology , The Townsville Hospital , Douglas , Queensland , Australia .,b Mothers and Babies Research Centre, Hunter Medical Research Institute, John Hunter Hospital, The University of Newcastle , Callaghan , New South Wales , Australia .,c College of Public Health, Medical and Veterinary Sciences, The James Cook University , Townsville City , Queensland , Australia , and
| | - David Watson
- d Department of Obstetrics and Gynaecology , The Townsville Hospital , Douglas , Queensland , Australia
| | - Donna Rudd
- c College of Public Health, Medical and Veterinary Sciences, The James Cook University , Townsville City , Queensland , Australia , and
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Absolute quantification of podocalyxin, a potential biomarker of glomerular injury in human urine, by liquid chromatography–mass spectrometry. J Chromatogr A 2015; 1397:81-5. [DOI: 10.1016/j.chroma.2015.04.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Revised: 03/20/2015] [Accepted: 04/01/2015] [Indexed: 12/30/2022]
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Wang P, Li M, Liu Q, Chen B, Ji Z. Detection of urinary podocytes and nephrin as markers for children with glomerular diseases. Exp Biol Med (Maywood) 2014; 240:169-74. [PMID: 25245074 DOI: 10.1177/1535370214548995] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The purpose of this study was to detect the urinary podocytes and its related protein, nephrin, in the urine of the children with glomerular disease in order to analyze the relationship of the clinical testing with the significance of the glomerular disease. A total of 65 children with nephrotic syndrome were selected for this study. The podocytes and nephrin were detected in the urinary sediment by indirect immunofluorescence, enzyme-linked immunosorbent assay, and Western blotting. The urinary podocytes and nephrin positive rates were 53.8% and 50.8%, respectively, in the children with glomerular disease. The serum total protein and albumin decreased in the podocyte-positive children, while the urine total protein at 24 h, urinary albumin/creatinine ratio, blood urea nitrogen, and serum creatinine were significantly elevated as compared to those of the podocyte-negative patients. Furthermore, the results were the same in the patients with positive nephrin as compared to that of the patients with negative nephrin. The podocyte number and nephrin level were significantly higher in the lupus nephritis group as compared to those of the other groups. Likewise, the podocyte number and nephrin level dramatically increased in the focal segmental glomerulosclerosis group as compared to those of the mesangial proliferative glomerulonephritis and minimal change disease groups. In addition, the podocyte numbers and nephrin expression were significantly higher in severe proteinuria group as compared to those of the mild proteinuria group. The urinary nephrin expression was positively related to podocyte and urinary albumin/creatinine ratio. We concluded that the detection of the urinary podocytes and nephrin could be taken as markers for children with glomerular disease, reflecting the type of the disease. Therefore, this can be used as a noninvasive method to evaluate the severity of the kidney disease in children.
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Affiliation(s)
- Pei Wang
- The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou 510182, China
| | - Min Li
- The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou 510182, China
| | - Qicai Liu
- The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou 510182, China
| | - Bo Chen
- The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou 510182, China
| | - Zequan Ji
- The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou 510182, China
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Carlos CP, Sonehara NM, Oliani SM, Burdmann EA. Predictive usefulness of urinary biomarkers for the identification of cyclosporine A-induced nephrotoxicity in a rat model. PLoS One 2014; 9:e103660. [PMID: 25072153 PMCID: PMC4114979 DOI: 10.1371/journal.pone.0103660] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2014] [Accepted: 07/03/2014] [Indexed: 01/13/2023] Open
Abstract
The main side effect of cyclosporine A (CsA), a widely used immunosuppressive drug, is nephrotoxicity. Early detection of CsA-induced acute nephrotoxicity is essential for stop or minimize kidney injury, and timely detection of chronic nephrotoxicity is critical for halting the drug and preventing irreversible kidney injury. This study aimed to identify urinary biomarkers for the detection of CsA-induced nephrotoxicity. We allocated salt-depleted rats to receive CsA or vehicle for 7, 14 or 21 days and evaluated renal function and hemodynamics, microalbuminuria, renal macrophage infiltration, tubulointerstitial fibrosis and renal tissue and urinary biomarkers for kidney injury. Kidney injury molecule-1 (KIM-1), tumor necrosis factor-alpha (TNF-α), interleukin 6 (IL-6), fibronectin, neutrophil gelatinase-associated lipocalin (NGAL), TGF-β, osteopontin, and podocin were assessed in urine. TNF-α, IL-6, fibronectin, osteopontin, TGF-β, collagen IV, alpha smooth muscle actin (α -SMA) and vimentin were assessed in renal tissue. CsA caused early functional renal dysfunction and microalbuminuria, followed by macrophage infiltration and late tubulointerstitial fibrosis. Urinary TNF-α, KIM-1 and fibronectin increased in the early phase, and urinary TGF-β and osteopontin increased in the late phase of CsA nephrotoxicity. Urinary biomarkers correlated consistently with renal tissue cytokine expression. In conclusion, early increases in urinary KIM-1, TNF-α, and fibronectin and elevated microalbuminuria indicate acute CsA nephrotoxicity. Late increases in urinary osteopontin and TGF-β indicate chronic CsA nephrotoxicity. These urinary kidney injury biomarkers correlated well with the renal tissue expression of injury markers and with the temporal development of CsA nephrotoxicity.
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Affiliation(s)
- Carla Patrícia Carlos
- Division of Nephrology, São José do Rio Preto Medical School, São José do Rio Preto, SP, Brazil
- Department of Biology, Instituto de Biociências, Letras e Ciências Exatas, São Paulo State University, São José do Rio Preto, SP, Brazil
| | - Nathália Martins Sonehara
- Department of Biology, Instituto de Biociências, Letras e Ciências Exatas, São Paulo State University, São José do Rio Preto, SP, Brazil
| | - Sonia Maria Oliani
- Department of Biology, Instituto de Biociências, Letras e Ciências Exatas, São Paulo State University, São José do Rio Preto, SP, Brazil
| | - Emmanuel A. Burdmann
- Division of Nephrology, São José do Rio Preto Medical School, São José do Rio Preto, SP, Brazil
- LIM 12, Division of Nephrology, University of São Paulo Medical School, São Paulo, SP, Brazil
- * E-mail:
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16
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Absolute quantification of podocin, a potential biomarker of glomerular injury in human urine, by liquid chromatography–multiple reaction monitoring cubed mass spectrometry. J Pharm Biomed Anal 2014; 94:84-91. [DOI: 10.1016/j.jpba.2014.01.019] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Revised: 01/07/2014] [Accepted: 01/10/2014] [Indexed: 11/23/2022]
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17
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ELISA analysis of urinary nephrin and podocalyxin standardized by aquaporin-2 in adult patients with nephrotic syndrome. J Nephrol 2014; 27:411-7. [PMID: 24737246 DOI: 10.1007/s40620-014-0066-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Accepted: 12/31/2013] [Indexed: 10/25/2022]
Abstract
OBJECTIVE To investigate urinary nephrin and podocalyxin standardized by aquaporin (AQP)-2 using the enzyme-linked immunosorbent assay (ELISA) method in adult nephrotic syndrome (NS) patients. METHODS In 107 adult NS patients (27 proliferative nephritis, 77 non-proliferative, and 3 amyloidosis) undergoing renal biopsy, urinary nephrin, podocalyxin and AQP2 were measured by ELISA. Urinary nephrin and podocalyxin were standardized by AQP2 (neph/AQP and PCX/AQP) and values were compared with 11 healthy controls. RESULTS Urinary neph/AQP correlated positively to PCX/AQP (r = 0.51, p < 0.001). Urinary neph/AQP and PCX/AQP were lower in controls than NS patients. Both proliferative and non-proliferative NS patients excreted high urinary neph/AQP and PCX/AQP without a significant difference between them (p > 0.05). Patients with focal segmental glomerular sclerosis (FSGS) excreted higher urinary neph/AQP (p = 0.09) and PCX/AQP (p < 0.05) compared to the other patients. Urinary neph/AQP and PCX/AQP were increased in the immunoglobulin M nephropathy patients. Amyloidosis patients excreted lower neph/AQP and PCX/AQP. The sensitivity was 0.87 and specificity 0.37 when the neph/AQP borderline value of 0.16 was adopted [area under the curve (AUC) = 0.61]. The sensitivity was 0.74 and specificity 0.61 when the PCX/AQP borderline value was 3.06 (AUC = 0.69). CONCLUSIONS Urinary neph/AQP and PCX/AQP are increased in NS patients, with FSGS patients showing the highest levels. To distinguish FSGS from other NS forms, the measurement of urinary PCX/AQP may be a practical method, and superior to neph/AQP.
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Wickman L, Afshinnia F, Wang SQ, Yang Y, Wang F, Chowdhury M, Graham D, Hawkins J, Nishizono R, Tanzer M, Wiggins J, Escobar GA, Rovin B, Song P, Gipson D, Kershaw D, Wiggins RC. Urine podocyte mRNAs, proteinuria, and progression in human glomerular diseases. J Am Soc Nephrol 2013; 24:2081-95. [PMID: 24052633 DOI: 10.1681/asn.2013020173] [Citation(s) in RCA: 95] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Model systems demonstrate that progression to ESRD is driven by progressive podocyte depletion (the podocyte depletion hypothesis) and can be noninvasively monitored through measurement of urine pellet podocyte mRNAs. To test these concepts in humans, we analyzed urine pellet mRNAs from 358 adult and pediatric kidney clinic patients and 291 controls (n=1143 samples). Compared with controls, urine podocyte mRNAs increased 79-fold (P<0.001) in patients with biopsy-proven glomerular disease and a 50% decrease in kidney function or progression to ESRD. An independent cohort of patients with Alport syndrome had a 23-fold increase in urinary podocyte mRNAs (P<0.001 compared with controls). Urinary podocyte mRNAs increased during active disease but returned to baseline on disease remission. Furthermore, urine podocyte mRNAs increased in all categories of glomerular disease evaluated, but levels ranged from high to normal, consistent with individual patient variability in the risk for progression. In contrast, urine podocyte mRNAs did not increase in polycystic kidney disease. The association between proteinuria and podocyturia varied markedly by glomerular disease type: a high correlation in minimal-change disease and a low correlation in membranous nephropathy. These data support the podocyte depletion hypothesis as the mechanism driving progression in all human glomerular diseases, suggest that urine pellet podocyte mRNAs could be useful for monitoring risk for progression and response to treatment, and provide novel insights into glomerular disease pathophysiology.
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Abstract
The increasing burden of chronic kidney disease worldwide and recent advancements in the understanding of pathologic events leading to kidney injury have opened up new potential avenues for therapies to further diminish progression of kidney disease by targeting the glomerular filtration barrier and reducing proteinuria. The glomerular filtration barrier is affected by many different metabolic and immune-mediated injuries. Glomerular endothelial cells, the glomerular basement membrane, and podocytes—the three components of the filtration barrier—work together to prevent the loss of protein and at the same time allow passage of water and smaller molecules. Damage to any of the components of the filtration barrier can initiate proteinuria and renal fibrosis. Transforming growth factor-beta (TGF-β) is a pleiotropic cytokine strongly associated with the fibrogenic response. It has a known role in tubulointerstitial fibrosis. In this review we will highlight what is known about TGF-β and how it interacts with the components of glomerular filtration barrier and causes loss of function and proteinuria.
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Affiliation(s)
- Ayesha Ghayur
- Division of Nephrology, McMaster University, Hamilton, Ontario, Canada
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Kelder TP, Penning ME, Uh HW, Cohen D, Bloemenkamp KWM, Bruijn JA, Scherjon SA, Baelde HJ. Quantitative polymerase chain reaction-based analysis of podocyturia is a feasible diagnostic tool in preeclampsia. Hypertension 2012; 60:1538-44. [PMID: 23090771 DOI: 10.1161/hypertensionaha.112.201681] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
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.
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Affiliation(s)
- Tim P Kelder
- Department of Pathology, Leiden University Medical Center, Leiden, the Netherlands
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22
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Fukuda A, Wickman LT, Venkatareddy MP, Wang SQ, Chowdhury MA, Wiggins JE, Shedden KA, Wiggins RC. Urine podocin:nephrin mRNA ratio (PNR) as a podocyte stress biomarker. Nephrol Dial Transplant 2012; 27:4079-87. [PMID: 22863839 DOI: 10.1093/ndt/gfs313] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Proteinuria and/or albuminuria are widely used for noninvasive assessment of kidney diseases. However, proteinuria is a nonspecific marker of diverse forms of kidney injury, physiologic processes and filtration of small proteins of monoclonal and other pathologic processes. The opportunity to develop new glomerular disease biomarkers follows the realization that the degree of podocyte depletion determines the degree of glomerulosclerosis, and if persistent, determines the progression to end-stage kidney disease (ESKD). Podocyte cell lineage-specific mRNAs can be recovered in urine pellets of model systems and in humans. In model systems, progressive glomerular disease is associated with decreased nephrin mRNA steady-state levels compared with podocin mRNA. Thus, the urine podocin:nephrin mRNA ratio (PNR) could serve as a useful progression biomarker. The use of podocyte-specific transcript ratios also circumvents many problems inherent to urine assays. METHODS To test this hypothesis, the human diphtheria toxin receptor (hDTR) rat model of progression was used to evaluate potentially useful urine mRNA biomarkers. We compared histologic progression parameters (glomerulosclerosis score, interstitial fibrosis score and percent of podocyte depletion) with clinical biomarkers [serum creatinine, systolic blood pressure (BP), 24-h urine volume, 24-h urine protein excretion and the urine protein:creatinine ratio(PCR)] and with the novel urine mRNA biomarkers. RESULTS The PNR correlated with histologic outcome as well or better than routine clinical biomarkers and other urine mRNA biomarkers in the model system with high specificity and sensitivity, and a low coefficient of assay variation. CONCLUSIONS We concluded that the PNR, used in combination with proteinuria, will be worth testing for its clinical diagnostic and decision-making utility.
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Affiliation(s)
- Akihiro Fukuda
- Nephrology Division, Departments of Internal Medicine, University of Michigan, Ann Arbor, MI, USA
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23
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Jiang WL, Peng YM, Liu YH, Liu H, Chen GC, Xu XQ, Zhu XJ, Liu FY. Evaluation of renal clinicopathological changes in IgA nephropathy by urinary podocytes excretion and podocalyxin expression. Ren Fail 2012; 34:821-6. [PMID: 22679920 DOI: 10.3109/0886022x.2011.643352] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVE To explore the association of urinary podocyte excretion and renal expression of podocyte-specific marker podocalyxin (PCX) with clinicopathological changes in immunoglobulin A nephropathy (IgAN). METHODS Morning urine samples from IgAN patients and healthy controls were collected. The expression of glomerular PCX was quantified in 50 IgAN patients diagnosed by renal biopsy. IgAN was classified based on the Lee's Grading system and scored according to the Katafuchi semiquantitative criteria. Morphological evaluation of podocyte was determined by electron microscopy. RESULTS The amount of urinary podocytes in the IgAN patients was significantly higher than that in the healthy controls (p < 0.01). Pairwise comparison among Lee's grades of IgAN showed that the median of urinary podocytes in Lee's I-II group was lower than that in Lee's III, IV, and V groups (p < 0.05); group III lower than group V (p < 0.05). The positive rate of urinary podocytes was the highest in Lee's IV and V groups (100%), and lowest in Lee's I-II group (55%). Multiple comparison among groups of Lee's grades of IgAN showed that the glomerular PCX expression in Lee's I-II group was higher than that in Lee's III, IV, and V groups (p < 0.05); groups III and IV higher than group V (p < 0.05). The amount of urinary podocytes in IgAN patients was negatively correlated with PCX expression (r = -0.702, p < 0.01), but positively correlated with 24-h urinary protein (r = 0.465, p < 0.01) and glomerular (r = 0.233, p < 0.01) and renal tubular pathological scores (r = 0.307, p < 0.05). The glomerular PCX expression was negatively correlated with 24-h urinary protein (r = -0.367, p < 0.05) and glomerular (r = -0.560, p < 0.05) and tubular pathological scores (r = -0.377, p < 0.05). Electron microscopy showed significant changes in podocytes of IgAN, especially in the foot process. CONCLUSION The amount of urinary podocyte can reflect the loss of podocytes in renal tissue, which may be a marker of IgAN progression.
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Affiliation(s)
- Wen-ling Jiang
- Department of Nephrology, The Second Xiangya Hospital, Renal Research Institute of Central South University, Central South University, Changsha, PR China
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Wang Y, Zhao S, Loyd S, Groome LJ. Increased urinary excretion of nephrin, podocalyxin, and βig-h3 in women with preeclampsia. Am J Physiol Renal Physiol 2012; 302:F1084-9. [PMID: 22301621 DOI: 10.1152/ajprenal.00597.2011] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
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.
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Affiliation(s)
- Yuping Wang
- Department of Obstetrics and Gynecology, Louisiana State University Health Sciences Center, Shreveport, LA 71130, USA.
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Ghayur A, Liu L, Kolb M, Chawla A, Lambe S, Kapoor A, Margetts PJ. Adenovirus-mediated gene transfer of TGF-β1 to the renal glomeruli leads to proteinuria. THE AMERICAN JOURNAL OF PATHOLOGY 2011; 180:940-951. [PMID: 22203053 DOI: 10.1016/j.ajpath.2011.11.023] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2011] [Revised: 11/01/2011] [Accepted: 11/11/2011] [Indexed: 10/14/2022]
Abstract
The mechanism of proteinuria in many common kidney diseases involves glomerular hemodynamic effects and local expression of angiogenic, fibrogenic, and vasoactive factors. Transforming growth factor (TGF)-β has been associated with many diseases involving proteinuria and renal fibrosis. TGF-β has been shown to induce podocyte dedifferentiation in vitro, but its in vivo effects on the glomerular filtration barrier are not well described. In this study, we used an adenovirus vector to transfer active TGF-β1 to the glomeruli of rat kidneys. Transient TGF-β1 overexpression induced significant proteinuria, podocyte foot process effacement, nephrin down-regulation, and nephrinuria. The expression of synaptopodin was also significantly down-regulated by TGF-β1. Increased glomerular expression of Snail, suggestive of an in vivo dedifferentiation process, was associated with a loss of podocyte epithelial markers. The expression of angiopoietin-1 and angiopoietin-2 was significantly increased in TGF-β1-transfected glomeruli, and TGF-β1 increased the expression of the angiopoietin receptor, Tie2, in podocyte cell culture. TGF-β1 down-regulated nephrin and synaptopodin expression in podocytes in cell culture; this effect was reversed by the blockade of both angiopoietin and Tie2 activities. These findings suggest that locally produced TGF-β1 can cause podocyte dedifferentiation marked by a loss of synaptopodin, nephrin, and foot process effacement, partly regulated by angiopoietins. This process represents a novel pathway that may explain proteinuria in a variety of common renal diseases.
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Affiliation(s)
- Ayesha Ghayur
- Department of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Limin Liu
- Department of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Martin Kolb
- Department of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Arun Chawla
- Department of Surgery, McMaster University, Hamilton, Ontario, Canada
| | - Shahid Lambe
- Department of Surgery, McMaster University, Hamilton, Ontario, Canada
| | - Anil Kapoor
- Department of Surgery, McMaster University, Hamilton, Ontario, Canada
| | - Peter J Margetts
- Department of Medicine, McMaster University, Hamilton, Ontario, Canada.
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Angiotensin II-dependent persistent podocyte loss from destabilized glomeruli causes progression of end stage kidney disease. Kidney Int 2011; 81:40-55. [PMID: 21937979 DOI: 10.1038/ki.2011.306] [Citation(s) in RCA: 120] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Podocyte depletion is a major mechanism driving glomerulosclerosis. Progression is the process by which progressive glomerulosclerosis leads to end stage kidney disease (ESKD). In order to determine mechanisms contributing to persistent podocyte loss, we used a human diphtheria toxin transgenic rat model. After initial diphtheria toxin-induced podocyte injury (over 30% loss in 4 weeks), glomeruli became destabilized, resulting in continued autonomous podocyte loss causing global podocyte depletion (ESKD) by 13 weeks. This was monitored by urine mRNA analysis and by quantitating podocytes in glomeruli. Similar patterns of podocyte depletion were found in the puromycin aminonucleoside and 5/6 nephrectomy rat models of progressive end-stage disease. Angiotensin II blockade (combined enalapril and losartan) restabilized the glomeruli, and prevented continuous podocyte loss and progression to ESKD. Discontinuing angiotensin II blockade resulted in recurrent glomerular destabilization, podocyte loss, and progression to ESKD. Reduction in blood pressure alone did not reduce proteinuria or prevent podocyte loss from destabilized glomeruli. The protective effect of angiotensin II blockade was entirely accounted for by reduced podocyte loss. Thus, an initiating event resulting in a critical degree of podocyte depletion can destabilize glomeruli and initiate a superimposed angiotensin II-dependent podocyte loss process that accelerates progression resulting in eventual global podocyte depletion and ESKD. These events can be monitored noninvasively in real-time through urine mRNA assays.
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Camici M, Carpi A, Cini G, Galetta F, Abraham N. Podocyte dysfunction in aging--related glomerulosclerosis. Front Biosci (Schol Ed) 2011; 3:995-1006. [PMID: 21622249 DOI: 10.2741/204] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
We review podocyte molecular structure and function, consider the underlying mechanisms related to podocyte dysfunction and propose that podocyte dysfunction be considered in the evaluation and management of age-associated glomerulosclerosis. With aging, progressive sympathetic activation, increased intrarenal renin-angiotensin system (RAS) activity, endothelin system and oxidative stress and reduced nitric oxide (NO)-availability can damage podocytes. Apoptosis and proliferation are the principal podocyte changes following injury with the latter leading to sclerosis and loss of nephrons. Podocyte loss can be evaluated by either determining their average number in biopsed glomeruli or by estimating podocyte number or their associated molecules in urine sediment. Podocyturia may be considered a marker of active glomerular disease. Preliminary data suggest that antiadrenergic drugs, angiotensin converting enzyme (ACE) inhibitors, RAS blocking drugs, endothelin system inhibitors and reduced oxidative stress can protect podocytes. Thus podocytes appear to play an important role in the pathogenesis, evaluation and therapy of age related glomerulosclerosis.
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Affiliation(s)
- Marcello Camici
- Department of Internal Medicine, Pisa University, Pisa, Italy
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Urinary podocyte-associated mRNA profile in various stages of diabetic nephropathy. PLoS One 2011; 6:e20431. [PMID: 21655212 PMCID: PMC3105067 DOI: 10.1371/journal.pone.0020431] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2011] [Accepted: 04/20/2011] [Indexed: 11/19/2022] Open
Abstract
Background Podocyte injury and subsequent excretion in urine play a crucial role in the pathogenesis and progression of diabetic nephropathy (DN). Quantification of messenger RNA (mRNA) expression in urinary sediment by real-time PCR is emerging as a noninvasive method of screening DN-associated biomarkers. We hypothesized that the urinary mRNA profile of podocyte-associated molecules may provide important clinical insight into the different stages of diabetic nephropathy. Methods DN patients (N = 51) and healthy controls (N = 13) were enrolled in this study. DN patients were divided into a normoalbuminuria group (UAE<30 mg/g, n = 17), a microalbuminuria group (UAE 30∼300 mg/g, n = 15), and a macroalbuminuria group (UAE>300 mg/g, n = 19), according to their urinary albumin excretion (UAE). Relative mRNA abundance of synaptopodin, podocalyxin, CD2-AP, α-actin4, and podocin were quantified, and correlations between target mRNAs and clinical parameters were examined. Results The urinary mRNA levels of all genes studied were significantly higher in the DN group compared with controls (p<0.05), and mRNA levels increased with DN progression. Urinary mRNA levels of all target genes positively correlated with both UAE and BUN. The expression of podocalyxin, CD2-AP, α-actin4, and podocin mRNA correlated with serum creatinine (r = 0.457, p = 0.001; r = 0.329, p = 0.01; r = 0.286, p = 0.021; r = 0.357, p = 0.006, respectively). Furthermore, podocalyxin mRNA was found to negatively correlate with eGFR (r = −0.349, p = 0.01). Conclusion The urinary mRNA profiles of synaptopodin, podocalyxin, CD2-AP, α-actin4, and podocin were found to increase with the progression of DN, which suggested that quantification of podocyte-associated molecules will be useful biomarkers of DN.
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Navarro-Muñoz M, Ibernon M, Pérez V, Ara J, Espinal A, López D, Bonet J, Romero R. Messenger RNA expression of B7-1 and NPHS1 in urinary sediment could be useful to differentiate between minimal-change disease and focal segmental glomerulosclerosis in adult patients. Nephrol Dial Transplant 2011; 26:3914-23. [DOI: 10.1093/ndt/gfr128] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
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Wang G, Lai FMM, Lai KB, Chow KM, Kwan BCH, Li KTP, Szeto CC. Intra-renal and urinary mRNA expression of podocyte-associated molecules for the estimation of glomerular podocyte loss. Ren Fail 2010; 32:372-9. [DOI: 10.3109/08860221003611737] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Gutwein P, Schramme A, Abdel-Bakky MS, Doberstein K, Hauser IA, Ludwig A, Altevogt P, Gauer S, Hillmann A, Weide T, Jespersen C, Eberhardt W, Pfeilschifter J. ADAM10 is expressed in human podocytes and found in urinary vesicles of patients with glomerular kidney diseases. J Biomed Sci 2010; 17:3. [PMID: 20070888 PMCID: PMC2843607 DOI: 10.1186/1423-0127-17-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2009] [Accepted: 01/13/2010] [Indexed: 12/03/2022] Open
Abstract
Background The importance of the Notch signaling in the development of glomerular diseases has been recently described. Therefore we analyzed in podocytes the expression and activity of ADAM10, one important component of the Notch signaling complex. Methods By Western blot, immunofluorescence and immunohistochemistry analysis we characterized the expression of ADAM10 in human podocytes, human urine and human renal tissue. Results We present evidence, that differentiated human podocytes possessed increased amounts of mature ADAM10 and released elevated levels of L1 adhesion molecule, one well known substrate of ADAM10. By using specific siRNA and metalloproteinase inhibitors we demonstrate that ADAM10 is involved in the cleavage of L1 in human podocytes. Injury of podocytes enhanced the ADAM10 mediated cleavage of L1. In addition, we detected ADAM10 in urinary podocytes from patients with kidney diseases and in tissue sections of normal human kidney. Finally, we found elevated levels of ADAM10 in urinary vesicles of patients with glomerular kidney diseases. Conclusions The activity of ADAM10 in human podocytes may play an important role in the development of glomerular kidney diseases.
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Affiliation(s)
- Paul Gutwein
- Pharmazentrum frankfurt/ZAFES, University Hospital Goethe University Frankfurt, Frankfurt am Main, Germany.
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Abstract
PURPOSE OF REVIEW Focal and segmental glomerulosclerosis occurs due to a defect in the glomerular filtration barrier. This review highlights contributions from the past year that have enhanced our understanding of the pathophysiology of focal and segmental glomerulosclerosis with emphasis on discoveries which may lead to the identification of therapeutic targets. RECENT FINDINGS Slit diaphragm proteins have become increasingly important in signal transduction and in mediating downstream events. Actin polymerization occurs after the podocin-nephrin-Neph-1 complex is phosphorylated by Src kinase and Fyn. Recent studies of angiotensin receptor antagonists, corticosteroids and erythropoietin unravel new mechanisms that ameliorate proteinuria by targeting the cell cycle within the podocyte. The discovery that an N-acetylmannosamine kinase (MNK) mutant mouse has glomerulopathy is suggestive that human sialylation pathways may represent therapeutic targets. Proteinuria before podocyte effacement demonstrated in laminin-beta2 null mice highlights the importance of the glomerular basement membrane. Interferon-beta reduced proteinuria in three models of kidney injury, showing greatest effect on glomerular endothelial cells in vitro. SUMMARY Basic research has illuminated mechanisms by which classic therapies have antiproteinuric effects directly on the podocyte. As knowledge expands with improved molecular techniques, understanding signaling pathways in health and proteinuric states should lead to potential therapeutic targets in focal and segmental glomerulosclerosis.
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