Proteomic analysis and identification of aqueous humor proteins with a pathophysiological role in diabetic retinopathy.

Diabetic retinopathy (DR) can cause irreversible blindness and is the severest microvascular complication in the eyes of patients with diabetic mellitus (DM). The identification of susceptibility factors contributing to development of DR is helpful for identifying predisposed patients and improving treatment efficacy. Although proteomics analysis is useful for identifying protein markers related to diseases, it has never been used to explore DR-associated susceptibility factors in the aqueous humor (AH). To better understand the pathophysiology of DR and to identify DR-associated risk factors, a gel-based proteomics analysis was performed to compare AH protein profiles of DM patients with and without development of DR. MALDI-TOF MS was then performed to identify protein spots that were differentially expressed between the two groups and western blot analysis was used to validate the expressional change of protein demonstrated by proteomics. Our proteomics and bioinformatics analysis identified 11 proteins differentially expressed between DR and control groups. These proteins are linked to biological networks associated with nutrition transport, microstructure reorganization, angiogenesis, anti-oxidation, and neuroprotection. The data may provide potential AH biomarkers and susceptibility factors for predicting DR development, and provide an insight into the underlying pathophysiological mechanisms of DR. This article is part of a Special Issue entitled: Proteomics: The clinical link.

Impact of taxol on dermal papilla cells--a proteomics and bioinformatics analysis.

Dermal papilla (DP) cells play a regulatory role in hair growth, and also play a role in alopecia (hair loss). However, effects of taxol, which is a widely used chemotherapy drug, on DP cells remain unclear, despite that theoretically taxol can impact on DP cells to contribute to taxol-induced alopecia. To better understand pathophysiology of taxol-induced damage in DP cells, morphological and biochemical analyses were performed to check whether taxol can cause apoptosis in cultured DP cells or not. If it can, proteomics and bioinformatics analyses were then performed to investigate the protein networks which are impacted by the taxol treatment. Our data showed that taxol can cause apoptotic damage in DP cells in a concentration-dependant manner, as demonstrated by various apoptotic markers. Proteomic analysis on DP cells treated with the lowest apoptosis-inducible concentration of taxol revealed that taxol can affect expression of proteins involved in Ca2+-regulated biological processes, vesicles transport, protein folding, reductive detoxification, and biomolecules metabolism. Furthermore, bioinformatics analysis indicated that taxol can impact on multiple biological networks. Taken together, this biochemical, proteomics, and bioinformatics data may give an insight into pathophysiology of taxol-induced damage in DP cells and shed light on mechanisms underlying taxol-induced alopecia.

Urinary proteome and potential biomarkers associated with serial pathogenesis steps of focal segmental glomerulosclerosis.

BACKGROUND: Focal segmental glomerulosclerosis (FSGS) is a chronic nephropathy showing characteristic glomerular sclerosis. So far, the diagnosis and prognosis of FSGS rely mainly on the invasive biopsy. Searching for potential FSGS-associated urinary biomarkers representing pre-sclerotic and serial sclerotic stages of FSGS could be helpful to the non-invasive diagnosis and prognosis of FSGS. METHODS: In the present study, we used a 2D gel-based proteomic approach to identify urinary proteins at pre-sclerotic and different sclerotic stages of an FSGS mouse model in order to find FSGS-related urinary proteins. The FSGS mouse model was established in Balb/c mice by a single injection of adriamycin, and disease severity was monitored by renal biological parameters and histopathological features. Urine was collected on days 0, 4, 7, 11, 15 and 20, and subjected to two-dimensional electrophoresis (2-DE) analysis. Proteins were identified by matrix-assisted laser desorption ionization/time of flight mass spectrometry (MALDI-TOF MS) and a protein database search. Some of the identified proteins were confirmed by western blot analysis. RESULTS: We identified 37 urinary proteins showing characteristic patterns of dynamic changes along the disease course of FSGS. Early urinary proteins appearing before glomerular sclerosis were noticed. Importantly, 11 urine proteins are novel to FSGS and have known functions highly associated with different pathogenetic steps of the disease, including haemodynamic disturbance, podocyte apoptosis, ECM-protein deposition and glomerular sclerosis. CONCLUSIONS: Some urinary proteins appearing earlier than glomerular sclerosis could serve as potential early diagnostic biomarkers. The proteins with the pathogenic roles could serve as potential non-invasive prognostic markers of FSGS, and give an insight into pathogenic mechanisms of this sclerosis disease.