Glomerular Proteomic Profiles in the NZB/W F1 Hybrid Mouse Model of Lupus Nephritis.

BACKGROUND Lupus nephritis is one of the most serious complications of systemic lupus erythematosus (SLE) and is associated with patient mortality. This study aimed to investigate the proteomic profiles of the glomerulus in the NZB/W F1 hybrid mouse model of mild and severe lupus nephritis using two-dimensional fluorescence difference gel electrophoresis (2D-DIGE) combined with matrix-assisted laser desorption time-of-flight mass spectrometry (MALDI-TOF-MS). MATERIAL AND METHODS Female NZB/WF1 mice (n=60) at 28 weeks of age were divided into the mild proteinuria group (+1), the moderate proteinuria group (+2), and the severe proteinuria group (+3) using paper strip urine testing, and then later divided into a mild (≤1+) and severe (≥3+) proteinuria group to allow comparison of upregulation and down-regulation of proteins between the two groups. Renal glomeruli were isolated following renal perfusion with magnetic beads. Protein expression was determined by Western blot, immunohistochemistry, 2D-DIGE, and MALDI-TOF-MS. RESULTS A total of 56 differentially expressed proteins were identified from 133 protein spots, of which 18 were upregulated and 23 were down-regulated between groups 1 and 2. Expression of the proteins Ras-related GTP-binding protein B (RRAGB), serine/threonine-protein kinase 1 (SMG1), angiopoietin 2 (ANGP2), methylmalonate semialdehyde (MMSA), and ATP beta chain (ATPB) were identified by Western blot and SMG1, ANGP2, and MMSA were identified by immunohistochemistry. CONCLUSIONS In a mouse model of lupus nephritis, expression of SMG1, MMSA, and ATPB were down-regulated, and RRAGB and ANGP2 were upregulated.

Identification of hepatic biomarkers for physiological imbalance of dairy cows in early and mid lactation using proteomic technology.

Identification of biomarkers for degree of physiological imbalance (PI), a situation in which physiological parameters deviate from normal, is needed to reduce disease risk and improve production and reproduction performance of cows. The objective was to describe the liver proteome in early and mid lactation for cows with different degrees of PI with a special focus on biomarkers and pathways involved in periparturient disease complexes. Twenty-nine cows in early [49 ± 22d in milk (DIM); n=14] and mid (159 ± 39 DIM; n=15) lactation were nutrient restricted for 4d to increase PI by supplementing the ration with 60% wheat straw. Liver biopsies were collected -1 and 3d relative to restriction. Before restriction, an index for PI was calculated based on plasma nonesterified fatty acids, ß-hydroxybutyrate, and glucose concentrations. Within E and M cows, a subsets of 6 cow was classified as having either the greatest (PI) or least (normal; N) degree of PI and were used for isobaric tags for relative and absolute quantitation (iTRAQ)-based quantitative profiling in liver using liquid chromatography-tandem mass spectrometry. We identified pyruvate carboxylase and isocitrate dehydrogenase as potential hepatic biomarkers for PI for cows during early lactation and alcohol dehydrogenase-4 and methylmalonate-semialdehyde dehydrogenase for cows in mid lactation. This preliminary study identified new biomarkers in liver for PI and provided a better understanding of the differences in coping strategies used for cows in PI. Despite the small sample size (n=3/group), the results lay a foundation for future research focused on the usefulness of the hepatic biomarkers for predicting PI and thereby cows at risk for disease during lactation.