Dietary potassium restriction reprograms the distal convoluted tubule (DCT) and induces proliferative DCT populations

Low potassium (K) intake has adverse health effects, including hypertension, osteoporosis, and nephrolithiasis. Dietary K restriction rapidly activates a K switch in the distal nephron to maintain homeostasis by activating the sodium chloride cotransporter (NCC) and thereby reducing K excretion; when K deficiency (KD) is prolonged, however, tubule remodeling occurs. This study investigates how short-term dietary potassium deficiency (4-day KD) drives transcriptional reprogramming and cellular state changes in the distal convoluted tubule (DCT). Using previously described single-nucleus RNA sequencing (snRNA-seq) on enriched DCT cells (PMID: 38238903), combined with immunohistochemistry, Western blot analysis, and pseudotime trajectory mapping, we evaluated early transcriptomic changes in DCT cells from KD-treated mice compared to normal K (NK) controls. Female NCC-Cre-INTACT mice were provided either normal K (NK) or KD diet for 4 days and kidneys were snap-frozen for targeted snRNAseq (10X Chromium, NovaSeq) (n=3, 10,000 nuclei per mouse). Four-day KD activates DCT cells, shifting them toward a K-sparing transcriptional state. Both DCT1 and DCT2 cells show altered expression profiles that reduce K excretion and promote sodium/chloride reabsorption. KD induces a 5.7-fold increase in proliferating cells (PMID: 33769948) in the DCT, predominantly within the DCT1 segment. These cells exhibit reduced expression of DCT1 markers (e.g., Parvalbumin) and enhanced expression of cell cycle-associated genes (e.g., Mki67), representing a de-differentiated, plastic state. Further analysis in cells expressing Mki67 or Top2a, two well-established proliferation markers, along with cells from the proliferation cells, identifies a novel proliferating-DCT1 (pro-DCT1) population, enriched under KD conditions. Pseudotime trajectory analysis indicates a linear trajectory from DCT1 to pro-DCT1, progressing to the proliferative population, with pro-DCT1 bridging differentiated DCT1 cells and proliferative population, reflecting adaptation to K deficiency. In summary, short-term K deficiency initiates transcriptional reprogramming in DCT cells, enabling rapid adaptation to prevent K wasting. The induction of the pro-DCT1 population highlights a previously unrecognized mechanism of cellular plasticity and proliferation. These findings provide insights into how acute dietary challenges remodel the distal nephron, with implications for understanding electrolyte homeostasis and associated pathologies. KidneyCure, DK51496, DK133220, DK098141, DK132066, K01DK121737, AHA 20CDA35320169, K01DK120790, LeDucq Transatlantic Network of Excellence 17CVD05 This abstract was presented at the American Physiology Summit 2025 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.