Hypertension and age-related focal global glomerulosclerosis are associated with biomarkers for cellular senescence.

Abstract

Arterionephrosclerosis is characterized by focal global glomerulosclerosis (FGGS), which is a constant feature of aging and hypertension. FGGS begins as normal-appearing glomeruli that undergo tuft contraction (TC) and progress to global glomerulosclerosis (GGS). Kidney tissue from 26 hypertensive and 25 age-matched non-hypertensive patients was analyzed for glomerular volume and for podocyte number using a WT1 antibody. Immunohistochemistry (IHC) was employed to detect the senescence-related biomarkers p16, p21, β-galactosidase (GLB1), and 5-nucleotidase (CD73). Antibodies against annexin 3 (ANXA3), cytokeratin 7, and CD44 were used to evaluate parietal epithelial cell (PEC) activation. The relationships between biomarkers, hypertension, TC, and GGS were quantitatively analyzed. With TC, podocyte numbers decreased in association with increased glomerular p16, p21, GLB1, and CD73 expression. With TC, WT1, CK7, and CD44-expressing PEC increased. TC and GGS expressed senescent markers in hypertensive and non-hypertensive kidneys; however, the frequency of TC (p < 0.01) and GGS (p < 0.001) was greater in hypertensive kidneys, and glomerular expression of senescence markers was correspondingly higher. Additionally, greater p16 and p21 expression was observed in the tubular atrophy of hypertension. As FGGS developed, podocyte depletion, cellular senescence markers, and PEC activation were associated with TC and increased with hypertension.