New Concepts in JGA Physiology

Symposium — Monday, April 23, 2024 — 8:30 AM - 10:00 AM — Convention Center, Room 25B
Renal Section — Chair: Janos Peti-Peterdi — Co-Chair: Charlotte Buckley

The juxtaglomerular apparatus (JGA) is a critically important microanatomical region in each nephron that is known as a chief regulator of renal and glomerular hemodynamics, body fluid and electrolyte homeostasis, and blood pressure maintenance. Among the JGA cell types, macula densa (MD) cells of the distal nephron are traditionally known as sensors of tubular fluid salt content, while the adjacent JG renin cells, mesangial cells, and afferent arteriole (AA) vascular smooth muscle cell function as the vascular effector component of the JGA. Classic physiological JGA functions include tubuloglomerular feedback (TGF) control of AA vasoactivity and renin secretion via the synthesis, release, and paracrine actions of MD-derived chemical mediators. However, several non-traditional functions of JGA cells are emerging. New data suggest that MD cells are master regulators of renal and cardiovascular tissue remodeling via new, locally and systemically acting secreted angiogenic peptides.  Cells of the renin lineage may function as precursors for glomerular epithelial cells. Also, renin cells and the renal interstitium play new endocrine roles. New anti-diabetic therapies shed new light on the clinical importance of the classic TGF mechanism in glomerular repair and renoprotection. These are exciting new developments for the audience this symposium aims to target. The purpose of this symposium is to address new mechanisms and aspects of traditional JGA functions (hemodynamics and renin) as well as totally new non-traditional JGA functions (tissue repair and regeneration, endocrine). Our goal is to emphasize that classic JGA physiology is key to improve our understanding of endogenous nephron repair, tissue regeneration, and renal and body homeostasis.

Speakers

• SGLT2 inhibitors and glomerular hemodynamics.
  Volker Vallon — Medicine, UCSD


• New role of macula densa cells in tissue remodeling.
  Georgina Gyarmati — Physiology and Biophysics, USC


• Imaging and manipulation of renin cells.
  Charlotte Buckley — Queen’s Medical Research Institute


• Non-canonical functions of renin cells: renal physiology, regeneration and beyond.
  Vladimir T. Todorov — Div. of Nephrology, Dept. of Med III, TU Dresden