Dataset Information

Proteomic-based research strategy identified laminin subunit alpha 2 as a potential urinary-specific biomarker for the medullary sponge kidney disease

ABSTRACT: Medullary sponge kidney (MSK) disease, a rare kidney malformation featuring recurrent renal stones and nephrocalcinosis, continues to be diagnosed using expensive and time-consuming clinical/instrumental tests (mainly urography). Currently, no molecular diagnostic biomarkers are available. To identify such we employed a proteomic-based research strategy utilizing urine from 22 patients with MSK and 22 patients affected by idiopathic calcium nephrolithiasis (ICN) as controls. Notably, two patients with ICN presented cysts. In the discovery phase, the urine of 11 MSK and 10 controls, were randomly selected, processed, and analyzed by mass spectrometry. Subsequently, several statistical algorithms were undertaken to select the most discriminative proteins between the two study groups. ELISA, performed on the entire patients’ cohort, was used to validate the proteomic results. After an initial statistical analysis, 249 and 396 proteins were identified exclusive for ICN and MSK, respectively. A Volcano plot and ROC analysis, performed to restrict the number of MSK-associated proteins, indicated that 328 and 44 proteins, respectively, were specific for MSK. Interestingly, 119 proteins were found to differentiate patients with cysts (all patients with MSK and the two ICN with renal cysts) from ICN without cysts. Eventually, 16 proteins were found to be common to three statistical methods with laminin subunit alpha 2 (LAMA-2) reaching the higher rank by a Support Vector Machine, a binary classification/prediction scheme. ELISA for LAMA-2 validated proteomic results. Thus, using high-throughput technology, our study identified a candidate MSK biomarker possibly employable in future for the early diagnosis of this disease.

INSTRUMENT(S): LTQ Orbitrap Velos

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Urine

SUBMITTER: Martina Bartolucci

LAB HEAD: Andrea Petretto

PROVIDER: PXD025744 | Pride | 2021-05-24

REPOSITORIES: Pride

ACCESS DATA

Similar Datasets

Project description:Purpose: Determine if gene expression profiles in urine sediment could provide non-invasive candidate markers for painful bladder syndrome (PBS) with and/or without Hunner lesions. Materials and Methods: Fresh catheterized urine was collected and centrifuged from control (n = 5), lesion-free (n = 5), and Hunner lesion bearing (n = 3) patients. RNA was extracted from the pelleted material and quantified by gene expression microarray (Affymetrix Human Gene ST Array). Results: Three biologically likely hypotheses were tested: A) all three groups are distinct from one another; B) controls are distinct from both types of PBS patients combined, and C) Hunner lesion PBS patients are distinct from controls and non-Hunner-lesion PBS combined. For statistical parity an unlikely fourth hypothesis was included: non-Hunner-lesion PBS patients are distinct from controls and Hunner lesion PBS combined. Analyses supported selective upregulation of genes in the Hunner lesion PBS group (hypothesis C), and these were primarily associated with inflammatory function. This profile is similar to that reported in a prior microarray study of bladder biopsies in Hunner lesion PBS. Conclusions: Urine sediment gene expression from non-Hunner-lesion PBS patients lacked a clear difference from that of control subjects, while the array signatures from PBS patients with Hunner lesions showed a clear, primarily inflammatory, signature. This signature was highly similar to that seen in a prior microarray study of bladder biopsies. Thus, although sample sizes were small, this work suggests that gene expression in urine sediment may provide a non-invasive biomarker for Hunner lesion, but not non-Hunner lesion, PBS. Urine (40-100 ml) was immediately placed on ice, transported to the laboratory and centrifuged at -4C for 5 minutes. Pellets were washed twice with ice-cold phosphate-buffered saline, suspended in 0.8 ml TRIzol and RNA was extracted according to the manufacturer's instructions. RNA was stored at -80oC until all samples had been collected, then analyzed at our Microarray Core Facility using the Affymetrix GeneChip Whole Transcript (WT) Sense Target Labeling Assay protocol, added to Human Gene 1.0 ST array chips, and annotated with gene symbol and functional information (Affymetrix). Probe level data were produced by Partek GS (6.10) using the gcRMA output option. Probe set signal intensities < 4.2 were considered absent, and if > 10 chips rated a probe set absent, that probe set was not considered for further analysis. Additionally, probe sets that did not have a gene symbol-level annotation (e.g., were considered 'hypothetical', or 'expressed sequence tags') were not considered for further analysis.

Dataset Information

Proteomic-based research strategy identified laminin subunit alpha 2 as a potential urinary-specific biomarker for the medullary sponge kidney disease

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure