Analysis Of Urinary Proteins Research Articles

Immunoglobulin D-Lambda Multiple Myeloma Initially Presenting in the Sphenoid Sinus, Orbital Apex, and Skull Base: A Systematic Review with a Case Report

Abstract Objectives Multiple myeloma (MM) with initial manifestations in the sphenoid sinus, orbital apex, and skull base is exceedingly rare. A systematic review was conducted to investigate the epidemiology and advancements. Methods Relevant cases were identified by searching CNKI, WanFang Data, CQVIP databases, PubMed, Embase, and Web of Science. Additionally, we present a case of IgD-λ (immunoglobulin D-lambda) MM with initial symptoms of dizziness, unilateral pain, blindness, and ophthalmoplegia, leading to a 4-month overall survival. Strictly based on PRISMA standards, we included and summarized existing cases and reflected our case. Results Our systematic review includes 34 case reports, revealing 67.6% of patients initially presented with diplopia and 44.1% underwent endoscopic procedures, notably with only two cases of IgD-λ subtype. In our case, we performed an endoscopic wide trans-ethmoidal sphenoidotomy and biopsy of the skull base and orbital apex lesion. Postoperative pathology confirmed a highly active plasmacytoma, clinically diagnosed as IgD-λ MM with a TP53 deletion mutation and multiple extramedullary metastases. A range of diagnostic tools was employed, including hemoglobin, immunoglobulin, urinary protein analysis, positron emission tomography-computed tomography (CT), bone marrow cytology, and gene detection. Conclusion The subtle clinical manifestations of IgD-λ MM in the paranasal sinuses and skull base hinder early diagnosis. There is a paucity of literature describing MM initially presenting in these locations. CT/magnetic resonance scans are necessary to identify characteristic bone destruction. An endoscopic approach is popular for tissue biopsy. Bone marrow biopsy with a smear, serum or urine protein electrophoresis, and immunofixation electrophoresis are crucial upon the appearance of target organ damage.

Megalin-related mechanism of hemolysis-induced acute kidney injury and the therapeutic strategy.

Hemolysis-induced acute kidney injury (AKI) is attributed to heme-mediated proximal tubule epithelial cell (PTEC) injury and tubular cast formation due to intratubular protein condensation. Megalin is a multiligand endocytic receptor for proteins, peptides, and drugs in PTECs and mediates the uptake of free hemoglobin and the heme-scavenging protein α1-microglobulin. However, understanding of how megalin is involved in the development of hemolysis-induced AKI remains elusive. Here, we investigated the megalin-related pathogenesis of hemolysis-induced AKI and a therapeutic strategy using cilastatin, a megalin blocker. A phenylhydrazine-induced hemolysis model developed in kidney-specific mosaic megalin knockout (MegKO) mice confirmed megalin-dependent PTEC injury revealed by the co-expression of kidney injury molecule-1 (KIM-1). In the hemolysis model in kidney-specific conditional MegKO mice, the uptake of hemoglobin and α1-microglobulin as well as KIM-1 expression in PTECs was suppressed, but tubular cast formation was augmented, likely due to the nonselective inhibition of protein reabsorption in PTECs. Quartz crystal microbalance analysis revealed that cilastatin suppressed the binding of megalin with hemoglobin and α1-microglobulin. Cilastatin also inhibited the specific uptake of fluorescent hemoglobin by megalin-expressing rat yolk sac tumor-derived L2 cells. In a mouse model of hemolysis-induced AKI, repeated cilastatin administration suppressed PTEC injury by inhibiting the uptake of hemoglobin and α1-microglobulin and also prevented cast formation. Hemopexin, another heme-scavenging protein, was also found to be a novel ligand of megalin, and its binding to megalin and uptake by PTECs in the hemolysis model were suppressed by cilastatin. Mass spectrometry-based semiquantitative analysis of urinary proteins in cilastatin-treated C57BL/6J mice indicated that cilastatin suppressed the reabsorption of a limited number of megalin ligands in PTECs, including α1-microglobulin and hemopexin. Collectively, cilastatin-mediated selective megalin blockade is an effective therapeutic strategy to prevent both heme-mediated PTEC injury and cast formation in hemolysis-induced AKI. © 2024 The Pathological Society of Great Britain and Ireland.

Prospective Multicenter Study on Early Proximal Tubular Injury in COVID-19–Related Acute Respiratory Distress Syndrome

IntroductionDuring COVID-19, renal impairment is the most frequent after lung impairment and is associated with poor prognosis particularly in intensive care unit (ICU). We aimed to assess the existence and incidence of early renal dysfunction and its prognostic value in patients with COVID-19-related acute respiratory distress syndrome (ARDS). MethodsIn this prospective multicenter study, patients aged over 18 years with invasive mechanical ventilation for ARDS were enrolled in 3 ICUs. Precise evaluation of renal dysfunction markers including urinary proteins electrophoresis (UPE) and quantification, was performed within 24 hours after mechanical ventilation onset. ResultsFrom March 2020 to December 2021, 135 patients were enrolled: 100 COVID-19 ARDS and 35 non-COVID-19 ARDS. UPE found more tubular dysfunction in COVID-19 patients (68% vs. 21.4%, p<0.0001) and more normal profiles in non-COVID-19 patients (65.0% vs. 11.2%, p=0.0003). COVID-19 patients significantly displayed early urinary leakage of tubular proteins like beta-2-microglobulin and free-light chains, tended to display more frequently acute kidney injury (AKI) (51.0% vs 34.3%, p=0.088), had longer mechanical ventilation (20 vs. 9 days, p<0.0001) and longer ICU stay (26 vs. 15 days, p<0.0001). In COVID-19 ARDS, leakage of free lambda light chain was associated with the onset of KDIGO ≥2 AKI (OR: 1.014, 95%CI [1.003-1.025], p=0.011). ConclusionsPatients with COVID-19-related ARDS display a proximal tubular dysfunction, prior to the onset of AKI, which predicts AKI. Proximal tubular damage seems an important mechanism of COVID-19-induced nephropathy. Analysis of urinary proteins is a reliable non-invasive tool to assess proximal tubular dysfunction in the ICU.

A correlation of 8-hour and 12-hour with 24-hour urinary protein among pregnant women with preeclampsia in a teaching hospital in South-Western Nigeria

Background and Objective: Proteinuria is one of the cardinal features of preeclampsia, which is a common and potentially severe complication of pregnancy. This study sought to determine how the quantitative measurement of urine protein from 8-hour and 12- hour samples correlate with that of a 24-hour sample in diagnosing preeclampsia.&#x0D; Materials and Methods: 52 eligible pregnant women with preeclampsia were recruited between April 2017 and April 2018. For each patient, having emptied the bladder at 0 hour, urine was collected into three different containers (containers 1, 2, 3) at 8th hour, 12th hour and 24th hour ensuring that the bladder was emptied into each container at hours 8, 12 and 24. Volumes of 8 hours urine (volume in container 1), 12 hours urine (total volume in containers 1 and 2), and 24 hours urine (total volumes in containers 1, 2 and 3) were measured and 5 ml aliquot respectively obtained from each sample for colorimetric analysis of urinary protein. Data was analyzed using the EPI Info software&#x0D; Results: A total of 52 patients completed the study. The mean gestational age was 33+ 2.82weeks. The mean 8-hour, 12-hour and 24-hour urinary protein values were 2.1+1.53, 2.3+1.52 and 3.1+1.89 respectively. There were significant correlations between the protein values of 8-and 12-hour urine samples with those of 24-hour urine samples&#x0D; Conclusion: 8-hour and 12-hour values of urine protein correlated positively with values in 24-hour samples and may be useful for initial assessment of cases of preeclampsia for prompt interventions.

Nanoparticle Tracking Analysis of Urinary Extracellular Vesicle Proteins as a New Challenge in Laboratory Medicine.

Urinary extracellular vesicle (uEV) proteins may be used as specific markers of kidney damage in various pathophysiological conditions. The nanoparticle-tracking analysis (NTA) appears to be the most useful method for the analysis of uEVs due to its ability to analyze particles below 300 nm. The NTA method has been used to measure the size and concentration of uEVs and also allows for a deeper analysis of uEVs based on their protein composition using fluorescence measurements. However, despite much interest in the clinical application of uEVs, their analysis using the NTA method is poorly described and requires meticulous sample preparation, experimental adjustment of instrument settings, and above all, an understanding of the limitations of the method. In the present work, we demonstrate the usefulness of an NTA. We also present problems encountered during analysis with possible solutions: the choice of sample dilution, the method of the presentation and comparison of results, photobleaching, and the adjustment of instrument settings for a specific analysis. We show that the NTA method appears to be a promising method for the determination of uEVs. However, it is important to be aware of potential problems that may affect the results.

La orina más allá de los electrolitos: diagnóstico a través de las vesículas extracelulares

Background and objectiveExtracellular vesicles (EVs) reflect the pathophysiological state of their cells of origin and are a reservoir of renal information accessible in urine. When biopsy is not an option, EVs present themselves as sentinels of function and damage, providing a non-invasive approach. However, the analysis of EVs in urine requires prior isolation, which slows down and hinders translation to clinical practice. The aim of this study is to show the applicability of the “single particle interferometric reflectance imaging sensor” (SP-IRIS) technology through the ExoView® platform for the direct analysis of urine EVs and proteins involved in renal function. Materials and methodsThe ExoView® technology enables the quantification and phenotyping of EVs present in urine and the quantification of their membrane and internal proteins. We have applied this technology to the quantification of urinary EVs and their proteins with renal tubular expression, amnionless (AMN) and secreted frizzled-related protein 1 (SFRP1), using only 5μl of urine. Tubular expression was confirmed by immunohistochemistry. ResultsThe mean size of the EVs analysed was 59±16nm for those captured by tetraspanin CD63, 61±16nm for those captured by tetraspanin CD81, and 59±10 nm for tetraspanin CD9, with CD63 being the majority EVs subpopulation in urine (48.92%). The distribution of AMN and SFRP1 in the three capture tetraspanins turned out to be similar for both proteins, being expressed mainly in CD63 (48.23% for AMN and 52.1% for SFRP1). ConclusionsThis work demonstrates the applicability and advantages of the ExoView® technique for the direct analysis of urine EVs and their protein content in relation to the renal tubule. The use of minimum volumes, 5μl, and the total analysis time not exceeding three hours facilitate the translation of EVs to daily clinical practice as source of diagnostic information.

Analysis of malnutrition factors for inpatients with chronic kidney disease.

Malnutrition is a common complication of Chronic Kidney Disease (CKD), and it is the risk factor of CKD prognosis. This study aim to evaluate the nutritional status of inpatients with CKD by using the Subjective Global Assessment (SGA), and to analyze the related factors of malnutrition; and to provide effective reference for early detection of malnutrition status in patients with CKD and timely nutrition intervention. A total of 426 patients (238 male patients, 188 female patients) aged 62.62 ± 14.61 and 61.14 ± 14.82, respectively admitted to the Nephrology Department of Wannan Medical College from February 2020 to December 2020 were selected and included in to this study by convenience sampling. 426 patients with CKD were evaluated by SGA. Human body weight, hemoglobin (Hb), total protein (TP), albumin (ALB), pre-albumin (PA), qualitative analysis of urinary protein and other laboratory indexes were collected and measured. The correlation between malnutrition and age, education, gender, diet, CKD stage and other factors was analyzed by spearman correlation analysis. The incidence of malnutrition was 85.7% among 426 patients with CKD. Gender, age, education level, CKD stage, diabetes mellitus, weight loss and reduced food intake were related to SGA nutritional assessment (P < 0.05). The expression levels of ALB, PA and Hb in the malnutrition group were significantly lower than those in the normal group (P < 0.05). The degree of malnutrition in CKD patients was significant negatively correlated with the expression levels of ALB (r = -0.188), PA (r = -0.262) and Hb (r = -0.176) (P < 0.05). The multivariate Logistic regression analysis model showed that female (OR = 2.155), ≥60 years old (OR = 7.671), weight loss (OR = 10.691), reduced food intake (OR = 28.953), moderate and severe serum ALB expression (OR = 3.391 and 8.326) were risk factors for malnutrition in patients with CKD (P < 0.05). Malnutrition was correlated with the results of qualitative examination of urinary protein (r = 0.268, P < 0.05). Gender, age, weight loss, reduced food intake, serum ALB expression were independently associated with malnutrition in patients with chronic kidney disease, Hence, the medical staff should take timely and effective nutrition intervention for the patients with malnutrition, delay the renal function damage of patients with CKD and improve the quality of life of patients. Inpatients with CKD, especially women, should increase their dietary intake, maintain normal weight and improve their nutritional status.

Suitability of estimated urine protein using different estimated 24 h urine creatinine equations in children with glomerular diseases

Objective: To assess the reliability of estimated urine protein to predict 24 h urine protein excretion in children with glomerular diseases. Methods: Four hundred and forty-three children with glomerular diseases, who were admitted to pediatric department of Peking University First Hospital from January 2001 to December 2021, were enrolled in the cross-sectional study. The 24 h estimated urine creatinine which calculated by 6 previously described equations, 24 h measured urine creatinine, measured urine protein-to-creatinine ratio(UPCR), 24 h urine protein (24 hUP) and urinary sediment analysis with microscopy were collected, estimated urine protein was computed as the product of measured UPCR and estimated or measured 24 h urine creatinine. Spearman correlation analysis, Bland-Altman analysis and linear regression analysis were used to compare the correlation, agreement and accuracy between estimated urine protein and 24 hUP, and the effect of urinary protein level and erythrocyte numbers on their relationship was analyzed. Results: Of 443 children with glomerular diseases (aged (11±4) years, 221 male, 222 female), there were 216 participants with nephrotic syndrome, 78 participants with IgA nephropathy, 47 participants with Alport syndrome, 42 participants with lupus nephritis, 58 participants with purpura nephropathy, and 2 participants with isolated proteinuria. Spearman correlation analysis showed a strong correlation between estimated urine protein and 24 hUP (r=0.90, P<0.05), and the correlation improved after multiplying the measured UPCR by 24 h measured urine creatinine (r=0.94, P<0.05). Improved correlation was also observed using the estimated urine creatinine which calculated by Hellerstein formula, Ghazali-Barratt formula, Ellam formula, Walser formula, Cockcroft-Gault formula, Ix formula (r=0.93, 0.94, 0.90, 0.90, 0.94, 0.93, all P<0.05).Bland-altman analysis showed that the difference between measured UPCR and 24 hUP was (-0.30±2.22) g, consistency limit was -4.65-4.04, and the consistency improved after 24 h measured urine creatinine correction (difference was (0.27±1.31) g, consistency limit -2.30-2.84). The consistency of estimated urine protein was further improved after correction by different formulas, and the Cockcroft-Gault formula showed the best consistency between estimated urine protein and 24 hUP (difference was (0.11±1.18)g, consistency limit was -2.20-2.42). Linear regression analysis showed that measured UPCR had poor accuracy in predicting 24 hUP (R2=0.55, α=0.48, β=0.60, P<0.05), and the accuracy improved after 24 h measured urine creatinine correction, the accuracy of estimated urine protein for predicting 24 hUP was further improved by using different formulas, and Cockcroft-Gault formula was the best (R2=0.81, α=0.18, β=0.96, P<0.05). With the increase of urinary protein level and the decrease of urinary erythrocyte numbers, the correlation, agreement and accuracy between estimated urine protein and measured UPCR and 24 hUP were improved(all P<0.05). Except Ellam and Ix formulas, estimated urine protein using the rest four formulas outperformed measured UPCR(all P<0.05). Conclusion: The 24 h urine creatinine excretion rate (obtained by the Cockcroft-Gault equation)-weighted urine protein-to-creatinine ratio more reliably predicts 24 hUP than measured UPCR alone in children with glomerular diseases.

Longitudinal analysis of urinary proteins in lupus nephritis – A pilot study

Approximately 30% of adult-onset systemic lupus erythematosus (SLE) patients develop lupus nephritis (LN). The gold standard for LN detection involves renal biopsies, invasive procedures not suitable for routine disease monitoring.A urinary biomarker panel comprised of lipocalin-like prostaglandin D synthase (LPGDS), transferrin, alpha-1-acid glycoprotein (AGP-1), ceruloplasmin, monocyte chemoattractant protein 1 (MCP-1) and soluble vascular cell adhesion molecule-1 (sVCAM-1) has shown promise to predict LN and response to rituximab at baseline. Whether these proteins predict LN during longitudinal sampling, however, remained unknown.Here, we quantified aforementioned urinary proteins at baseline (N = 25), six and twelve months (N = 17 each) after rituximab treatment. Urine MCP-1 (at six and twelve months) and AGP-1 (at twelve months) levels varied between patients with active vs mildly active/inactive LN.Findings support the use of urinary proteins to detect active LN in ongoing disease monitoring in adult-onset SLE patients, but need to be validated in larger cohorts.

Elevated urinary CD80 excretion in children with steroid-responsive nephrotic syndrome

Background: Idiopathic nephrotic syndrome (INS) is one of the most common glomerular diseases in children with different pathological types and different responses to corticosteroids. A definitive diagnosis is essential for planning the treatment and determining the prognosis of these patients and currently, kidney biopsy is the only method for definitive diagnosis. However, this is an invasive procedure. In addition, in some cases, the biopsy is contraindicated or tissue obtained on biopsy is insufficient and may not represent the underlying disease. According to the recent hypothesis about the role of circulating permeability factors in the pathogenesis of INS, urine protein analysis as a noninvasive method to determine the specific biomarkers of the disease is of great interest to nephrologists and can be useful. Methods: In this case − control study, we analyzed urinary CD80 (uCD80) levels in 51 patients with INS using a special CD80 enzyme-linked immunosorbent assay kit and were compared between different groups of patients. Results: The highest urine CD80/creatinine ratio was found in patients with active minimal change disease and steroid-responsive nephrotic syndrome in the relapse stage of the disease. Conclusion: A significant level of uCD80 is correlated with better renal function and a more favorable response to steroids in patients with INS. Therefore, it can be concluded that a high level of uCD80 is correlated with a good prognosis in these patients.

Comparative Analysis of Urinary Proteins in Donkey Foals and Adult Donkeys

Comparative Analysis of Urinary Proteins in Donkey Foals and Adult Donkeys

Determination of Urine Protein Levels and Analysis of Differences in Vascular Endothelial Growth Factor Levels between Early Onset and Late Onset Preeclampsia

BACKGROUND: Preeclampsia is a disease with the high mortality rate. Data indicate that 23.5% of maternal deaths due to preeclampsia. Urine protein testing is essential for pregnant women to discover the function of kidney during pregnancy and to identify the presence of preeclampsia, both mild and severe, which it can lead to eclampsia. Preeclampsia based on onset can also be detected by examining serum biomarkers of Vascular Endothelial Growth Factor (VEGF).&#x0D; AIM: The aim of this study was to overview the urine protein levels and analyzed the differences serum VEGF levels between the early and late onset of preeclampsia.&#x0D; MATERIALS AND METHODS: This study used design of the cross sectional comparative study in RSUP DR. M Djamil Padang, Pariaman Hospital, Aisiyah Pariaman Hospital, and Padang Pariaman Regional Hospital for 2 years. The population in this study consisted of patients with early and late onset preeclampsia who went to the study site during that time and met the inclusion criteria. Sampling with consecutive sampling consisted of 28 people per group.&#x0D; RESULTS: The results revealed that the number of patients who had urine protein levels with a value of 2+ at the early onset was 14 and at the late onset was 12, meanwhile for patients with a urine protein content value of 3+ at the early onset it was 14 and at the late onset was 10.For the category urine protein with a value of 4+ amounted to 6 people only in the late onset group. The results of the normality test showed that the mean value of VEGF levels at early onset and late onset was 3.91 pg / ml and 4.3 pg / ml, respectively. Thus, the level of VEGF serum had an abnormal distribution and it led to the T test data could not be tested. So then, the testing was done using a non-parametric test, namely the Mann-Whittney test. The mean levels of VEGF, respectively, based on the Mann-Whittney test for early onset preeclampsia and late onset preeclampsia were 29.75 ng / mL and 30.25 ng / mL. VEGF in early onset preeclampsia is lower than late onset preeclampsia.&#x0D; CONCLUSION: Based on the results obtained, it can be concluded that there was no significant difference in the level of VEGF in early onset preeclampsia and late onset preeclampsia (p = 0.42).&#x0D; Keywords: Preeclampsia, early onset, late onset, urine protein, VEGF

Maternal serum Apelin 13 and APLN gene promoter variant -1860T > C in preeclampsia

Objective To evaluate the apelin (APLN) −1860 T > C (rs56204867) polymorphism and maternal serum apelin 13 levels in preeclampsia and its association with blood pressure. Methods This case-control study was conducted in department of Biochemistry, Sri Devaraj Urs Medical College, Karnataka, India. A total of 181 subjects were enrolled in the study from department of Department of Obstetrics and Gynecology. The recruited women were grouped as: Group–I (n = 91) cases with preeclampsia and Group–II (n = 90) normotensive healthy pregnant women as controls. Under aseptic conditions, the collected 5 mL blood was distributed for serum separation (3 mL) and genetic analysis (2 mL). Serum was stored at −80 °C after centrifugation at 3000 rpm for 10 min. The collected five mL urine sample was used for urinary protein analysis by dipstick method. The APLN gene −1860 T > C polymorphism and Apelin 13 levels were analyzed by molecular methods and ELISA technique respectively. Birth weight and demographic details were recorded. Results In the present study, no significant difference was observed for mean gestational age and maternal age. Systolic (158.7 ± 14.0 mmHg) and diastolic (104.9 ± 10.7 mmHg) blood pressure, and mean arterial pressure (MAP) (123.0 ± 11.1 mmHg) (p-value .001) were significantly increased in preeclamptic women compared with healthy pregnant women. Birth weight (2.4 ± 0.5 kg) (p-value .001) was significantly decreased in babies born to preeclamptic mothers. Birth weights were also expressed in centiles, according to Fenton Chart. Number of small for gestational age (SGA) babies were more in preeclampsia (n = 55) than healthy pregnant women (n = 28). Mean maternal serum apelin 13 (239.4 ± 126.3 pg/mL) (p-value .001) concentrations were significantly lower in preeclampsia compared with healthy controls. Maternal serum apelin 13 concentration in preeclampsia was negatively correlated with systolic blood pressure (r = −0.235), diastolic blood pressure (r= −0.172) and mean arterial pressure (r = –0. 206). However, maternal serum apelin 13 levels showed insignificant positive correlation with age, gestational age and birth weight. The genotype and allele frequencies of APLN gene were found significant between study groups as in preeclampsia (χ2 = 11.69; df = 2; p = .0028 and χ2 = 14.27; df = 1; p = .00013 respectively). CC genotype and C allele of APLN − 1860 T > C site was high in preeclampsia. Conclusion Study concludes that preeclamptic women have low level of serum apelin 13 and −1860 T > C polymorphism at APLN gene promoter site with increased allelic frequency of CC genotype and C allele compared to normotensive pregnant women. And this evidence may link to cardiac complications in preeclamptic women after delivery in later stage.

Exploring molecular pathology of chronic kidney disease in systemic sclerosis by analysis of urinary and serum proteins.

Objective.Renal involvement is common in systemic sclerosis (scleroderma; SSc) and includes chronic kidney disease (CKD). We have performed analysis of urinary proteins to gain insight into local molecular pathology of CKD in SSc and identify candidate markers for use in clinical trials.Methods.To evaluate urinary proteins that might specifically reflect SSc-related CKD, patients were recruited with confirmed SSc and stratified for the presence or absence of CKD. Controls included patients with CKD and no SSc, in addition to healthy volunteers. Candidate markers were measured in serum and urine by multiplex immunoassay testing for IL6, IL18, TNF-α, monocyte chemoattractant protein 1 (MCP1), monocyte chemoattractant protein 3 (MCP3), VEGF and the soluble adhesion molecules vascular cell adhesion molecule 1 (VCAM-1) and intercellular adhesion molecule 1 (ICAM-1). Results.One hundred and two subjects were examined, including patients with SSc with no evidence of CKD (n = 40), SSc with CKD (n = 39), non-SSc CKD (n = 11) and healthy volunteers (n = 12). Urinary levels of IL6, MCP1, TNF-α, MCP3, IL18 and ICAM-1 were elevated in SSc patients compared with healthy controls. The most significant differences were for MCP1 and ICAM-1 (both P < 0.0001), and these analytes also showed the most significant differences between groups overall (P = 0.003 for MCP1 and P < 0.0001 for ICAM-1). These markers showed a trend (MCP1, P = 0.0868) or a significant difference (ICAM-1, P = 0.0134) between SSc–CKD and SSc with normal renal function.Conclusion.Urinary levels of candidate molecular markers appear to reflect SSc–CKD more than serum markers. MCP1 and ICAM-1 are promising molecular markers for SSc–CKD and might be potential biomarkers of SSc renal involvement. This might be explored in future prospective analyses.

Urinary protein analysis in mice lacking major urinary proteins.

Mouse urine contains major urinary proteins (MUPs) that are not found in human urine. Therefore, even healthy mice exhibit proteinuria, unlike healthy humans, making it challenging to use mice as models for human diseases. It was also unknown whether dipsticks for urinalysis could measure protein concentrations precisely in urine containing MUPs. To resolve these problems, we produced MUP-knockout (Mup-KO) mice by removing the Mup gene cluster using Cas9 proteins and two guide RNAs and characterized the urinary proteins in these mice. We measured the urinary protein concentrations in Mup-KO and wild-type mice using a protein quantitation kit and dipsticks. We also examined the urinary protein composition using SDS-PAGE and two-dimensional electrophoresis (2DE). The urinary protein concentration was significantly lower (P<0.001) in Mup-KO mice (17.9 ± 1.8 mg/dl, mean ± SD, n=3) than in wild-type mice (73.7 ± 8.2 mg/dl, n=3). This difference was not reflected in the dipstick values, perhaps due to the low sensitivity to MUPs. This suggests that dipsticks have limited ability to measure changes in MUPs with precision. SDS-PAGE and 2DE confirmed that Mup-KO mice, like humans, had no MUPs in their urine, whereas wild-type mice had abundant MUPs in their urine. The absence of the masking effect of MUPs in 2DE would enable clear comparisons of urinary proteins, especially low-molecular-weight proteins. Thus, Mup-KO mice may provide a useful model for human urinalysis.

Urinary exosome proteomic profiling defines stage-specific rapid progression of autosomal dominant polycystic kidney disease and tolvaptan efficacy

ADPKD is the most common genetic disease of the kidney leading to end-stage renal disease necessitating renal replacement therapy at any time between the 1st and 8th decades of life due to widely variable rates of disease progression. This presents significant patient anxiety and a significant prognostic and therapeutic challenge. Tolvaptan is the only approved drug licensed to slow ADPKD progression by reducing renal cystic expansion but side-effects can limit its efficacy.To address the need to identify new biomarkers to monitor progression of ADPKD and to evaluate the therapeutic effects of Tolvaptan, proteomic analysis was conducted on defined (40-100nm) urinary exosomes isolated from ADPKD patients phenotyped and clinically monitored over a 10-year period. Comparative Gene Ontology analysis of Tandem Mass Tag labelled mass spectrometry-derived protein profiles from urinary exosomes from ADPKD patients with rapid (>10ml/min/5 years decline in estimated glomerular filtration rate) versus slow progression showed distinctive patterns of pathway up-regulation. Clear discrimination between rapid and slowly-progressive profiles were seen in all stages functional decline in ADPKD patients whether with mild (>70ml/min), moderate (50-69ml/min) or severe (<49ml/min) disease at onset. Discriminatory pathways and proteins included Notch-, integrin- and growth factor-signalling; microtubular kinase, vesicular proteins and epidermal growth factor substrates.Confocal microscopy of fluorescently-labelled normal versus ADPKD epithelial cell-derived exosomes in vitro also identified ADPKD-dependent abnormalities in intracellular vesicular trafficking and implicated changes in ADPKD-dependent exosome secretion and target cell uptake as factors underlying urinary exosome excretion biomarker properties.Comparative proteomic analysis of urinary exosomal proteins in individual patients before and after treatment with Tolvaptan for 4 years also identified distinct patterns of pathway modification dependent on the degree of effectiveness of the therapeutic response. Up-regulation of Wnt-pathway and vesicular proteins were characteristic of urinary exosomes from ADPKD patients with good responses to Tolvaptan while upregulation of angiogenesis pathways and additional molecular forms of vasopressin receptor AVPR2 were characteristic in urinary exosomes of ADPKD patients with poor responses.Taken together, these studies conclude that proteomic profiling of urinary exosome biomarkers provides a specific, sensitive and practical non-invasive method to identify and monitor the rate of disease progression and the effects of Tolvaptan therapy in individual ADPKD patients. This provides a means to identify those patients most likely to benefit maximally from therapy and to progress towards a personalization of ADPKD prognosis and management.

The effect of ginger on blood sugar and urine protein in patients with type 2 diabetes mellitus; a clinical trial

Introduction: The prevalence of diabetes mellitus has been increasing exponentially and its complications are a major cause of morbidity and mortality. Ginger is one of the herbal remedies which has preventive effects on nephropathy in animal models in some studies. Objectives: We aimed to investigate the effect of ginger on urine protein analysis and blood glucose levels in diabetic patients. Patients and Methods: In a clinical trial, 98 patients with type 2 diabetes were randomly divided into two groups; the intervention group received 500 mg of Zingiber as capsule, daily in addition to routine therapies, since control group received only conventional treatments for diabetes. Before and after intervention, blood glucose, urine microalbumin and hemoglobin A1c (HbA1c) were measured. Results: The findings showed that Zingiber decreased HbA1c levels in diabetic patients (P=0.006), however, it did not have a significant effect on fasting blood glucose (P=0.179), 2 hours post-prandial glucose levels (P= 0.272), and the microalbuminuria quantity in urine (P=0.109). Conclusion: In our study, the hypoglycemic short-term effects of ginger observed as a reduction of HbA1c, however its effect on reducing blood glucose levels [FBS and 2 hours postprandial glucose (2hpp)] was not significant, therefore ginger can be considered as a supplementary agent in the treatment of diabetes. However it is recommended to conduct more studies to obtain results with more reliability. Trial registration: The trial protocol was approved by the Iranian Registry of Clinical Trial (identifier: IRCT2017103025732N27; https://www.irct.ir/trial/21503, ethical code; IR.SEMUMS.REC.1395.207).

Electrophoretic analysis (sds-page) of canine urinary proteins according to the stage of chronic kidney disease

ABSTRACT Glomerular proteinuria is characterized by the loss of high-molecular-weight proteins (HMWPs), while tubulointerstitial proteinuria is characterized by the loss of low-molecular-weight proteins (LMWPs). The objective was to assess the molecular weight of urinary proteins (MWUP) in dogs with naturally acquired CKD and determine the proportion of HMWPs and LMWPs according to CKD stage. Twenty-eight dogs with CKD were recruited and divided into 4 groups based on serum creatinine (Cr) levels (group1: Cr&lt;1,4, n=8; group2: 1,4&lt;Cr&lt;2,0, n=6; group3: 2,1&lt;Cr&lt;5, n=9; group4: Cr&gt;5,0, n=5). The control group consisted of 5 healthy dogs. The MWUP was determined by SDS-PAGE. The urinary protein-to-creatinine ratio (UP/C) was used to quantitatively assess proteinuria. The electrophoresis pattern revealed a proportionally greater loss of HMWPthan of LMWP in all groups with CKD and an increased loss of LMWP in group 4 (P&lt;0.05). These results suggest a predominance of glomerular injuries throughout all stages of CKD in these dogs and an increase in tubulointerstitial injury towards the end-stage of the disease. The results of the present study support the recommendation of SDS-PAGE as an effective technique for the qualitative assessment of proteinuria, as well as a method for assessing the severity and location of renal injury.

Differential analysis of urinary albumin for membranous nephropathy patients by online capillary isoelectric focusing - Mass spectrometry

Membranous nephropathy (MN) is one of the most common causes of primary glomerular diseases worldwide. The M-type phospholipase A2 receptor (PLA2R), an antigen expressed in more than 70% of cases of idiopathic membranous nephropathy (IMN), is a biomarker which is now used by physicians for clinical diagnosis. Despite the prevalence of PLA2R in the cases of MN, it is not always effective to use PLA2R for differentiating primary or secondary MNs. On the other hand, urinary albumin assay is one of the de facto tests for kidney function testing for several decades. In this work, urinary albumin species between primary and secondary MN patients are compared using a newly developed capillary isoelectric focusing – mass spectrometry (CIEF-MS) technology. The distinct patterns of cationic and acidic urinary albumin species, as revealed by this novel CIEF-MS technology, suggest potential applications of this differential analysis for subtyping of membranous nephropathy. Further investigation of these cationic human albumin species in urine may provide clues to the disease onset and development of MN, thus facilitating treatment. In addition, this novel workflow of using CIEF-MS for urinary protein analysis may be beneficial to the research, pathology, prognosis, and diagnosis of many other types of kidney diseases, such as chronic kidney disease, diabetic nephrology, etc.

The role of podocyte damage in the etiology of ischemia-reperfusion acute kidney injury and post-injury fibrosis

BackgroundTo establish a model of chronic renal fibrosis following acute kidney injury (AKI) in BALB/c mice and to observe the effect of AKI on podocyte injury and chronic fibrosis of the kidney. Additional aims included using the model to explore the role of podocyte injury in AKI and post-injury fibrosis.MethodsFifty BALB/C mice were randomly divided into control group (Ctr), sham group (sham), AKI 20 group (renal ischemia, 20 min reperfusion), AKI 30 group (renal ischemia, 30 min reperfusion) and AKI 40 group (renal ischemia, 40 min reperfusion). Mice serum and 24-h urine were collected on the 8th, 9th, 10th, 14th, and 28th days for urinary protein, serum creatinine (Scr) and blood urea nitrogen (BUN) analysis. HE staining, transmission electron microscopy (TEM), Masson staining, Q-PCR, Western Blot and immunohistochemistry were applied.ResultsSerum Scr and BUN levels across all AKI groups at the 9th day were significantly higher (P < 0.05) than controls, with higher reperfusion groups maintaining that increase up to 28 days (P < 0.05). Compared with Ctr group, the urinary protein of the AKI 40 group significantly rose on the 9th day (P < 0.05), normalizing immediately on the 10th day (P < 0.05). In contrast, the AKI 30 group rose significantly on the 14th day (P < 0.05) maintaining elevated levels for two weeks (P < 0.05). HE staining demonstrated ischemia-dependent renal tissue damage was aggravated in the mild to aggravated AKI groups. Mesangial proliferation, glomerulosclerosis, and tubulointerstitial pathology were also significantly increased in these groups (P < 0.05). Masson staining further showed that glomerular, renal tubular, and interstitial collagen were increased by ischemia in a time-dependent manner. Transmission EM additionally that podocytes of the mild to severe AKI groups displayed extensive fusion, exfoliation and GBM exposure. Synaptopodin, Nephrin, and CD2AP mRNA and protein expression demonstrated ischemic time-dependent decreases, while the TRPC6 was increased. There was a significant difference in the levels of Synaptopodin, Nephrin, CD2AP, and TRPC6 between the mild and severe AKI groups (P < 0.05).Conclusions1) During the AKI process mice podocyte injury, proteinuria and the subsequent progression into chronic renal fibrosis is observed.2) Podocyte injury may be one of the causes of ischemia-reperfusion acute kidney injury and post-injury fibrosis.