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Biology subjects

Stocker, S. D.

Publications and source records attributed to Stocker, S. D..

2 recordsLinked to original sources

Neuron-like function of the nephron central command

Interoceptive neurons that sense and regulate our internal milieu have been identified in several organs except in the kidney cortex despite its major importance in maintaining body homeostasis. Here we report that the chief kidney cell type of the macula densa (MD) forms coordinated neural networks in each nephron that resemble peripheral ganglia. A combined in vivo single-cell 4D physiology (sc4DP) and scRNA sequencing approach identified the MD mechanisms of neuronal differentiation, heterogeneity (pacemaker MD cells), sensing of the local and systemic environment via multi-organ crosstalk, and regulation of organ functions by acting as the nephron central command. Consistent with their neuron-like nature, MD cells express the molecular fingerprint of neurodegeneration. Here we put forth the single-cell MD model and concept of local neural networks that control organ and body functions via interoception in normal physiological state and use an integrated mechanism of neurodegeneration in disease.

physiology↗

Kidney-Specific WNK1 Amplifies NCC Responsiveness to Potassium Imbalance

To maintain potassium homeostasis, the kidneys distal convoluted tubule (DCT) converts small changes in blood [K+] into robust effects on salt reabsorption. This process requires NaCl cotransporter (NCC) activation by WNK kinases. During hypokalemia, the Kidney-Specific WNK1 isoform (KS-WNK1) scaffolds the DCT-expressed WNK signaling pathway within biomolecular condensates of unknown function termed WNK bodies. Here, we show that KS-WNK1 amplifies the dynamic range of NCC activity in response to potassium imbalance, in part via WNK bodies. Targeted condensate disruption traps the WNK pathway, causing renal salt-wasting that is more pronounced in females. In humans, WNK bodies accumulate as plasma potassium falls below 4.0mmol/L, suggesting avid condensate-mediated salt reabsorption even when [K+] is low-normal. These data identify WNK bodies as signal amplifiers that mediate tubular potassium responsiveness, nephron sexual dimorphism, and blood pressure salt-sensitivity. Our results illustrate how condensate specialization can optimize a mammalian physiologic stress response that impacts human health.

physiology↗