Global analysis of enriched glomerular extracellular matrix of pre-term foetuses of normoglycemic and hyperglycaemic mothers using mass spectrometry-based proteomics

Abstract

Maternal hyperglycaemia is likely to be the primary cause of the fuel-mediated embryonic distress in diabetic pregnancies that damage kidney development. The functional mechanisms of kidney developmental reprogramming in diabetic pregnancies have been widely investigated, nevertheless, little is known about the alterations in the glomerular extracellular matrix (ECM) during kidney development under this condition. We have been investigating how severe maternal hyperglycaemia affects nephrogenesis and its impact on the glomerular ECM in preterm foetuses. Using stereological tools, and gene expression and immunoaffinity-based approaches, we have observed that foetuses of diabetic mothers feature alterations in the renal microarchitecture quite similar to those found in individuals with diabetic nephropathy, e.g. corpuscular hypertrophy, increased accumulation of ECM glycoproteins and reduced content of heparan-sulphate proteoglycans within the glomerulus, thickened glomerular basement membrane and podocyte foot effacement (unpublished data from our current PhD project supported by FAPESP, process number 2015/03525-2). Recently, global proteomic approaches have been applied to investigate the composition of tissue-specific ECM at systems biology level of analysis. Studies using mass spectrometry (MS)-based proteomics have proven that the glomerular ECM is a niche far more complex than what had been previously described. Addressing the glomerular ECM proteome of foetuses of diabetic mothers could help to better characterize the hyperglycaemia-promoted alterations in its protein composition, and appreciate the likely ECM dysregulation as one potential mechanism of kidney developmental reprogramming in diabetic pregnancies. Therefore, in order to complement our current investigation, the proposed study aims to define and compare the proteome of enriched glomerular ECM of E19.0 mouse foetuses of both normoglycemic and hyperglycaemic mothers using MS-based proteomics. (AU)