Renal microdissection revisited: Lectin-aided sorting of intact tubular nephron segments as a new tool to study sex-related differences in kidney disease

Abstract In our aging society an increasing prevalence of chronic kidney disease (CKD) meets a general shortage of organ donors. As the economic burden of CKD is increasing, kidney research made significant progress in the early detection, repair, or replacement of damaged renal tissue, taking in consideration sex-related differences, and precision medicine principles. Despite recent advancements in renal organoid research, the generation of fully functional nephrons in-vitro is so far not achievable. Here we describe a novel lectin-guided protocol to sort renal tissue into four pure, functionally diverse nephron segments with high yield and intact 3D tubular morphology. We validated tissue-sorted fragments with proximal or distal convoluted tubular identity using bottom-up proteomics and assessed sex-related differences. Compared to males, females showed higher abundance of proteins involved in metabolism and excretion of xenobiotics, as well as in cell cycle progression or proliferation, which together might enhance their ability to better cope with renal injury. The major advantage of our protocol – high yield of sorted nephron segments with preserved 3D structure – will allow us to reconstruct miniature kidneys ex-vivo, by combining it with cutting-edge bio-printing techniques. Besides large-scale drug screening or the identification of segment specific biomarkers in renal disease, they could pave the way to generate functional renal replacement units for regenerative medicine. Furthermore, if applied to human biopsies, our method could improve patient-specific renal disease assessment. In conclusion, our method represents a cost-efficient and broadly applicable tool with the potential to propel personalized regenerative kidney research.