Multiscale Imaging of Human Adipose Tissue: A Neglected Partner in Proteinuria Linked to Obesity.

Nephrotic syndrome (NS) is a systemic disorder characterized not only by glomerular dysfunction but also by profound dysregulation of lipid metabolism and microvascular integrity. Adipose tissue, as a central lipid-handling and endocrine organ, undergoes structural and functional remodeling in chronic renal conditions yet remains underexplored in this context. The aim of this manuscript is to integrate adipose tissue imaging into the diagnostic and mechanistic framework of NS. To establish this perspective, we first summarize current knowledge on adipose tissue architecture and imaging in both physiological states and renal disease. We then present a multimodal imaging approach-combining ultrasound (US), histology, and atomic force microscopy (AFM)-applied to human adipose tissue as a potential diagnostic and pathophysiological marker in NS. Original imaging from our laboratory experience is presented as a demonstrative material, complemented by literature synthesis. Given that different modalities of imaging-based characterization of adipose tissue are sparse across the literature, this pictorial review offers a guide to identifying structural biomarkers of adipose remodeling in NS. By bridging imaging modalities with metabolic and vascular perturbations observed in NS, this work aims to guide future research toward the clinical application of adipose tissue imaging in renal disease. This provides insights into cell size heterogeneity, vascular topology, and subcellular features such as membrane wrinkles and nanodomain organization. We propose that such morphometric parameters, accessible via minimally invasive biopsies, could serve as surrogate markers of adipose remodeling in nephrotic syndrome. This sets the stage for integrating adipose tissue imaging into the diagnostic and mechanistic evaluation of systemic features in NS.