Tubule Epithelial Cell Markers

Tubule Epithelial Cell Overview

Renal tubules transport urinary filtrate from the renal corpuscle to the collecting duct. They consist of columnar epithelial cells that regulate osmotic balance and acid-base homeostasis. Distinct anatomical regions of the tubule show differential expression of electroneutral and electrogenic ion channels, water channels, and solute transporters. From Bowman’s capsule to the collecting duct, renal tubule sections include the proximal convoluted tubule (PCT), descending and ascending limbs of the loop of Henle, thick ascending limb (TAL), and distal convoluted tubule (DCT). Tight junctions between epithelial cells also allow selective paracellular ion flux. Epithelial cells of the macula densa regulate glomerular filtration rate (GFR) based on the Na⁺ concentration in the urinary filtrate. The high rate of glucose uptake by tubule epithelial cells is required to generate ATP for active sodium resorption. The cell surface localization of ion channels and transporters is under the control of various circulating molecules such as Vasopressin, Bradykinin, Aldosterone, Endothelin-1, Angiotensin, Prostaglandin E2, and Dopamine. Several tubule transporters (e.g. ENaC, SGLT2, NKCC2) are targets for loop diuretics and hyperglycemia medications. Renal cell carcinoma develops most commonly from tubule epithelial cells.