Nile red spectroscopy to evaluate disease-specific lipid alterations in glomerular kidney disease

Lipid accumulation has been implicated in the progression of chronic kidney disease (CKD), yet its role in glomerulonephritis (GN) remains poorly characterized. Here we use Nile Red (NR), a solvatochromic fluorophore that stains for lipid droplets (LDs) to examine LD distribution and lipid chemistry in glomerular diseases. Seventy-two kidney biopsy samples, including histologically diagnosed GN subtypes and control nephrectomy tissues, were stained with NR.Lipid droplets (LDs) were quantified using a semi-automated MATLAB-based image analysis pipeline and spectral emission profiles were generated to assess the emission ratio, reflecting differences in lipid composition. We found that GN subtypes exhibit distinct patterns of lipid accumulation and lipid polarity as evaluated by using a Nile Red emission ratio (NRER). Our study demonstrates the utility of NR fluorescence spectroscopy in detecting disease-specific lipid alterations in GN. The findings suggest that distinct lipid signatures may serve as pathological indicators, offering potential new diagnostic and mechanistic insights into glomerular disease.