The expression of cytoskeletal proteins in kidney specimens of children with primary focal segmental glomerulosclerosis

CelLock TM: an innovative standardized cell-block preparation procedure

The CelLock™ procedure kit is used to collect and prepare cellular specimens such as fine needle aspirates (FNA), cytology specimens, cultured cells, small tissue biopsies, and samples with scant tissue fragments or cells into a paraffin cell-block. This cell-block can be used for subsequent microtomy and staining using hematoxylin and eosin (H&E), special stains, immunohistochemistry (IHC), and applicable molecular techniques such as in situ hybridization (ISH). CelLock is a standardized method that provides optimal receipt, preservation, preparation, and processing of cell-blocks which, contain virtually all of the submitted specimens and are able to be embedded and sectioned in a reproducible fashion. The specimen contained within the cell-block is preserved such that all the cellular protein and genetic information is available for histological and ancillary testing.

Networks that link cytoskeletal regulators and diaphragm proteins underpin filtration function in Drosophila nephrocytes

Insect nephrocytes provide a valuable model for kidney disease, as they are structurally and functionally homologous to mammalian kidney podocytes. They possess an exceptional macromolecular assembly, the nephrocyte diaphragm (ND), which serves as a filtration barrier and helps maintain tissue homeostasis by filtering out wastes and toxic products. However, the elements that maintain nephrocyte architecture and the ND are not understood. We show that Drosophila nephrocytes have a unique cytoplasmic cluster of F-actin, which is maintained by the microtubule cytoskeleton and Rho-GTPases. A balance of Rac1 and Cdc42 activity as well as proper microtubule organization and endoplasmic reticulum structure, are required to position the actin cluster. Further, ND proteins Sns and Duf also localize to this cluster and regulate organization of the actin and microtubule cytoskeleton. Perturbation of any of these inter-dependent components impairs nephrocyte ultrafiltration. Thus cytoskeletal components, Rho-GTPases and ND proteins work in concert to maintain the specialized nephrocyte architecture and function.

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Drosophila nephrocytes have a unique cytoplasmic cluster of F-actin.

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Microtubules, Rho-GTPases and endoplasmic reticulum position the actin cluster.

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Nephrocyte diaphragm proteins localize to and regulate actin cluster organization.

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Perturbation of any of these inter-dependent components impairs ultrafiltration.

Glomerular nestin expression: possible predictor of outcome of focal segmental glomerulosclerosis in children

BACKGROUND

A high prevalence of chronic kidney disease among children with focal segmental glomerulosclerosis (FSGS) leads to a permanent quest for good predictors of kidney dysfunction. Thus, we carried out a retrospective cohort study in order to examine known clinical and morphological predictors of adverse outcome, as well as to investigate glomerular nestin expression as a potential new early predictor of kidney dysfunction in children with FSGS. Relationships between nestin expression and clinical and morphological findings were also investigated.

METHODS

Among 649 renal biopsy samples, obtained from two children's hospitals, FSGS was diagnosed in 60 children. Thirty-eight patients, who met the criteria for this study, were followed up for 9.0 ± 5.2 years. Using Kaplan-Meier and Cox's regression analysis, potential clinical and morphological predictors were applied in two models of prediction: after disease onset and after the biopsy.

RESULTS

The present study revealed the following significant predictors of kidney dysfunction: patients' ages at disease onset, as well as age at biopsy, resistance to corticosteroid treatment, serum creatinine level, urine protein/creatinine ratio, vascular involvement, tubular atrophy, interstitial fibrosis, and decreased glomerular nestin expression.

CONCLUSIONS

The most important finding of our study is that nestin can be used as a potential new early morphological predictor of kidney dysfunction in childhood onset of FSGS, since nestin has been obviously decreased in both sclerotic and normal glomeruli seen by light microscopy.

Association of neutrophil gelatinase associated lipocalin and cystatin-C with kidney function in children with nephrotic syndrome

BACKGROUND

Nephrotic syndrome (NS) is a major clinical concern in human health, especially in children. Despite of the etiology, the prediction of remission in different treatment regimens based on suitable biomarkers is under development. The goal of this evaluation was the demonstration of correlation between serum level of Neutrophil gelatinase associated lipocalin (NGAL) and cystatin-C with kidney function in patients with NS.

METHODS

During the period between September 2008 and December 2011, 52 patients admitted to St. Al Zahra University Hospital were selected for evaluation. The measured parameters consisted of NGAL, cystatin-C, creatinine, albumin, blood urea nitrogen, urine protein, glomerular filtration rate. Demographic data were collected and considered in comparisons. Comparison between variables and their correlations were examined.

RESULTS

Means of serum NGAL and cystatin-C were significantly higher in case than the control group, P < 0.05. The mean of serum NGAL in patients without remission and who achieved remission were 23.09 (standard deviation [SD] ±10.11) and 36.26 (SD ± 20.10) ng/ml respectively; P < 0.05. Serum NGAL levels had a correlation with the following factors: Systolic blood pressure, diastolic blood pressure (DBP), cystatin-C, remission. Linear regression analysis showed a significant correlation between cystatin-C and systolic and DBP.

CONCLUSIONS

Based on the results, serum NGAL can be used as a prognostic marker for remission. In addition, NGAL and cystatin-C are biomarkers of kidney injury in NS.